Add StepEntryTranslator for IStep to view entry mapping

Bridges the runner's IStep / IActionRunner types to the renderer's
JobExecutionViewEntry (#PR1b). Given a runtime step, produces the
data the renderer needs to emit one entry in the execution view.

Specifically:
  - Determines the entry's phase from ActionRunStage / IStep type.
  - Filters JobExtensionRunner and other non-IActionRunner steps:
    those represent runner-internal scaffolding, not user-visible
    steps.
  - Filters auto-generated step IDs (regex against `^__\d+$` and
    GUID-shaped strings) so only explicit `id:` fields surface.
  - Serializes `with:` and `env:` via TemplateTokenYamlAdapter
    (#PR1d) so `${{ ... }}` expressions are preserved verbatim in
    the rendered source.
  - Extracts `run:`, `shell:`, `working-directory:` from a script
    step's `Inputs` map using the constants defined in
    PipelineConstants.ScriptStepInputs (the runner stores these as
    camelCase `workingDirectory`, not the kebab-case spelling from
    workflow YAML).

This is part 5 of 5 splitting the previously-monolithic foundation.
The DAP-integration PR wires this into JobRunner / ExecutionContext
so steps actually flow into the execution view at runtime.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

.gitignore

@@ -27,5 +27,4 @@ TestResults
 TestLogs
 .DS_Store
 .mono
-**/*.DotSettings.user
-**/*.lscache
+**/*.DotSettings.user

src/Misc/externals.sh

@@ -7,7 +7,7 @@ NODE_ALPINE_URL=https://github.com/actions/alpine_nodejs/releases/download
 # When you update Node versions you must also create a new release of alpine_nodejs at that updated version.
 # Follow the instructions here: https://github.com/actions/alpine_nodejs?tab=readme-ov-file#getting-started
 NODE20_VERSION="20.20.2"
-NODE24_VERSION="24.16.0"
+NODE24_VERSION="24.15.0"
 
 get_abs_path() {
   # exploits the fact that pwd will print abs path when no args

src/Runner.Worker/Dap/DapDebugger.cs

@@ -16,10 +16,19 @@ using Microsoft.DevTunnels.Connections;
 using Microsoft.DevTunnels.Contracts;
 using Microsoft.DevTunnels.Management;
 using Newtonsoft.Json;
-using Pipelines = GitHub.DistributedTask.Pipelines;
 
 namespace GitHub.Runner.Worker.Dap
 {
+    /// <summary>
+    /// Stores information about a completed step for stack trace display.
+    /// </summary>
+    internal sealed class CompletedStepInfo
+    {
+        public string DisplayName { get; set; }
+        public TaskResult? Result { get; set; }
+        public int FrameId { get; set; }
+    }
+
     /// <summary>
     /// Single public facade for the Debug Adapter Protocol subsystem.
     /// Owns the full transport, handshake, step-level pauses, variable
@@ -42,12 +51,8 @@ namespace GitHub.Runner.Worker.Dap
         // Frame ID for the current step (always 1)
         private const int _currentFrameId = 1;
 
-        // Frame ID for the static "job" frame anchored at line 1 of the execution view.
-        private const int _jobFrameId = 2;
-
-        // MVP serves a single synthesized source per session (the job's execution view).
-        // Stable session-scoped ID 1; future sources (composite step-in) will use higher IDs.
-        private const int _executionViewSourceReference = 1;
+        // Frame IDs for completed steps start at 1000
+        private const int _completedFrameIdBase = 1000;
 
         private TcpListener _listener;
         private TcpClient _client;
@@ -88,11 +93,11 @@ namespace GitHub.Runner.Worker.Dap
         // Current execution context
         private IStep _currentStep;
         private IExecutionContext _jobContext;
+        private int _currentStepIndex;
 
-        // Set true once OnJobCompletedAsync begins its inspection pause.
-        // While set, HandleStackTrace surfaces the synthetic "Complete job"
-        // frame so the client highlights the cleanup line.
-        private bool _jobCompleted;
+        // Track completed steps for stack trace
+        private readonly List<CompletedStepInfo> _completedSteps = new List<CompletedStepInfo>();
+        private int _nextCompletedFrameId = _completedFrameIdBase;
 
         // Client connection tracking for reconnection support
         private volatile bool _isClientConnected;
@@ -103,8 +108,6 @@ namespace GitHub.Runner.Worker.Dap
         // REPL command executor for run() commands
         private DapReplExecutor _replExecutor;
 
-        private JobExecutionView _executionView;
-
         public bool IsActive =>
             _state == DapSessionState.Ready ||
             _state == DapSessionState.Paused ||
@@ -249,10 +252,6 @@ namespace GitHub.Runner.Worker.Dap
                     {
                         if (_jobContext != null)
                         {
-                            lock (_stateLock)
-                            {
-                                _jobCompleted = true;
-                            }
                             Trace.Info("Job completed — pausing for inspection");
                             SendStoppedEvent("completed", "Job completed — inspect variables before the session ends.");
 
@@ -261,8 +260,7 @@ namespace GitHub.Runner.Worker.Dap
                     }
                     catch (Exception ex)
                     {
-                        Trace.Warning("DAP job-completed pause error.");
-                        Trace.Error(ex);
+                        Trace.Warning($"DAP job-completed pause error: {ex.Message}");
                     }
                 }
 
@@ -272,8 +270,7 @@ namespace GitHub.Runner.Worker.Dap
                 }
                 catch (Exception ex)
                 {
-                    Trace.Warning("DAP OnJobCompleted error.");
-                    Trace.Error(ex);
+                    Trace.Warning($"DAP OnJobCompleted error: {ex.Message}");
                 }
             }
         }
@@ -390,8 +387,7 @@ namespace GitHub.Runner.Worker.Dap
             }
             catch (Exception ex)
             {
-                Trace.Warning("DAP OnStepStarting error.");
-                Trace.Error(ex);
+                Trace.Warning($"DAP OnStepStarting error: {ex.Message}");
             }
         }
 
@@ -404,7 +400,10 @@ namespace GitHub.Runner.Worker.Dap
 
             try
             {
+                var result = step.ExecutionContext?.Result;
                 Trace.Info("Step completed");
+
+                // Add to completed steps list for stack trace
                 lock (_stateLock)
                 {
                     if (_state != DapSessionState.Ready &&
@@ -414,336 +413,20 @@ namespace GitHub.Runner.Worker.Dap
                         return;
                     }
 
-                    // Clear current-step ref if it matches; otherwise leave alone
-                    // (defensive — OnStepStartingAsync may have already advanced it).
-                    if (ReferenceEquals(_currentStep, step))
+                    _completedSteps.Add(new CompletedStepInfo
                     {
-                        _currentStep = null;
-                    }
+                        DisplayName = step.DisplayName,
+                        Result = result,
+                        FrameId = _nextCompletedFrameId++
+                    });
                 }
             }
             catch (Exception ex)
             {
-                Trace.Warning("DAP OnStepCompleted error.");
-                Trace.Error(ex);
+                Trace.Warning($"DAP OnStepCompleted error: {ex.Message}");
             }
         }
 
-        /// <summary>
-        /// Snapshot of the current job execution view, or null if it has not
-        /// been built yet (debugger inactive, or InitializeJob has not yet
-        /// signalled). Phase 2c will consume this for DAP source/stack-trace
-        /// responses.
-        /// </summary>
-        internal JobExecutionView ExecutionView
-        {
-            get
-            {
-                lock (_stateLock)
-                {
-                    return _executionView;
-                }
-            }
-        }
-
-        public async Task OnJobStepsInitializedAsync(IEnumerable<IStep> mainQueue, IEnumerable<IStep> initialPostStack)
-        {
-            if (!IsActive)
-            {
-                return;
-            }
-
-            try
-            {
-                IExecutionContext jobContext;
-                lock (_stateLock)
-                {
-                    jobContext = _jobContext;
-                }
-
-                string jobId = jobContext?.GetGitHubContext("job");
-                if (string.IsNullOrWhiteSpace(jobId))
-                {
-                    jobId = "job";
-                }
-
-                // Materialize mainQueue once so we can iterate it twice
-                // (once for entries, once for the post-step predictor).
-                var mainSteps = mainQueue == null ? new List<IStep>() : new List<IStep>(mainQueue);
-
-                var entries = new List<(JobExecutionViewEntry entry, IStep stepIdentity)>();
-                foreach (var step in mainSteps)
-                {
-                    var entry = StepEntryTranslator.TryTranslate(step);
-                    if (entry != null)
-                    {
-                        entries.Add((entry, step));
-                    }
-                }
-                // Stack<T>.GetEnumerator() yields items in LIFO order — the
-                // same order callers will pop them. We materialize them into
-                // the view in that pop order so post-step entries appear in
-                // execution order.
-                if (initialPostStack != null)
-                {
-                    foreach (var step in initialPostStack)
-                    {
-                        var entry = StepEntryTranslator.TryTranslate(step);
-                        if (entry != null)
-                        {
-                            entries.Add((entry, step));
-                        }
-                    }
-                }
-
-                var view = new JobExecutionView(jobId);
-                if (entries.Count > 0)
-                {
-                    view.AppendRange(entries);
-                }
-
-                // Predict Post-step placeholders for actions that declare
-                // HasPost in their action manifest. Walking Pre+Main runners
-                // in declaration order, then prepending each prediction so
-                // the rendered post section matches the runner's LIFO
-                // post-execution order (the runner's post stack pops in
-                // reverse-registration order). Wrapped in a try/catch so a
-                // missing IActionManager or LoadAction failure cannot
-                // prevent the view from being published.
-                try
-                {
-                    PredictPostPlaceholders(jobContext, mainSteps, view);
-                }
-                catch (Exception ex)
-                {
-                    Trace.Warning("DAP predictor: predicting post placeholders failed; continuing without predictions.");
-                    Trace.Error(ex);
-                }
-
-                lock (_stateLock)
-                {
-                    _executionView = view;
-                }
-
-                Trace.Info($"DAP execution view initialized with {view.EntryCount} entries.");
-                SendLoadedSourceEvent("new");
-            }
-            catch (Exception ex)
-            {
-                Trace.Warning("DAP OnJobStepsInitialized error.");
-                Trace.Error(ex);
-            }
-
-            await Task.CompletedTask;
-        }
-
-        public void OnPostStepRegistered(IStep step)
-        {
-            if (!IsActive || step == null)
-            {
-                return;
-            }
-
-            try
-            {
-                JobExecutionView view;
-                lock (_stateLock)
-                {
-                    view = _executionView;
-                }
-
-                if (view == null)
-                {
-                    return;
-                }
-
-                // Try to claim a previously-predicted placeholder. When
-                // OnJobStepsInitializedAsync ran, we walked the Pre+Main
-                // queue and synthesized a Post placeholder for every action
-                // whose manifest declared HasPost. If this registration
-                // matches one of those placeholders by Action.Id, claim it
-                // in place — no view growth, no `loadedSource changed`
-                // event needed.
-                if (step is IActionRunner postRunner && postRunner.Action != null)
-                {
-                    var matchKey = MatchKeyFor(postRunner.Action.Id);
-                    if (view.TryClaim(matchKey, step).HasValue)
-                    {
-                        return;
-                    }
-                }
-
-                // Unpredicted path: composite-action JIT post discovery,
-                // container hooks, or any other registration we did not
-                // foresee at view-build time. Fall back to append + notify
-                // clients via `loadedSource changed`.
-                var entry = StepEntryTranslator.TryTranslate(step);
-                if (entry == null)
-                {
-                    return;
-                }
-
-                try
-                {
-                    view.Append(entry, step);
-                    SendLoadedSourceEvent("changed");
-                }
-                catch (InvalidOperationException ex)
-                {
-                    // Step already registered — RegisterPostJobStep tolerates
-                    // duplicate registrations in some workflow shapes; mirror
-                    // that semantics here so we don't propagate.
-                    Trace.Info($"DAP OnPostStepRegistered: duplicate step ignored ({ex.Message}).");
-                }
-            }
-            catch (Exception ex)
-            {
-                Trace.Warning("DAP OnPostStepRegistered error.");
-                Trace.Error(ex);
-            }
-        }
-
-        /// <summary>
-        /// Walks <paramref name="mainSteps"/> (the queue of Pre+Main
-        /// IActionRunners produced by JobRunner) and synthesizes a Post
-        /// placeholder entry on <paramref name="view"/> for every action
-        /// whose manifest declares <c>HasPost = true</c>.
-        ///
-        /// Conditions mirror <c>ActionRunner.RunAsync</c> exactly:
-        /// the runner is in Pre or Main stage, the action is a
-        /// <see cref="Pipelines.RepositoryPathReference"/> that is NOT the
-        /// self-repository alias, the action is not a script, and the
-        /// resolved <see cref="Definition"/> reports HasPost.
-        ///
-        /// Predictions are collected in declaration order, then APPENDED
-        /// in reverse so the rendered post section mirrors the runner's
-        /// LIFO post-execution order (the runner's post stack pops in
-        /// reverse-registration order — see ExecutionContext.RegisterPostJobStep).
-        /// </summary>
-        private void PredictPostPlaceholders(IExecutionContext jobContext, IReadOnlyList<IStep> mainSteps, JobExecutionView view)
-        {
-            if (jobContext == null || mainSteps == null || mainSteps.Count == 0 || view == null)
-            {
-                return;
-            }
-
-            IActionManager actionManager;
-            try
-            {
-                actionManager = HostContext.GetService<IActionManager>();
-            }
-            catch (Exception ex)
-            {
-                Trace.Info($"DAP predictor: IActionManager unavailable ({ex.Message}); skipping post-step prediction.");
-                return;
-            }
-
-            var predictions = new List<(JobExecutionViewEntry entry, string matchKey)>();
-            var seenActionIds = new HashSet<Guid>();
-
-            foreach (var step in mainSteps)
-            {
-                if (step is not IActionRunner runner)
-                {
-                    continue;
-                }
-                if (runner.Stage == ActionRunStage.Post)
-                {
-                    // Post entries are already seeded from initialPostStack.
-                    continue;
-                }
-                var action = runner.Action;
-                if (action == null)
-                {
-                    continue;
-                }
-                // ActionRunner.cs:113 — Post only created when the action is
-                // a RepositoryPathReference that is not the self-repository
-                // alias and not a script.
-                if (action.Reference is not Pipelines.RepositoryPathReference repoRef)
-                {
-                    continue;
-                }
-                if (string.Equals(repoRef.RepositoryType, Pipelines.PipelineConstants.SelfAlias, StringComparison.OrdinalIgnoreCase))
-                {
-                    continue;
-                }
-                // (A RepositoryPathReference is never a script — script
-                // run-steps surface as a different ActionStepDefinitionReference
-                // subclass, so the cast above already filtered them out.)
-                // Dedupe by Action.Id: the runtime dedups via
-                // Root.StepsWithPostRegistered.Add(actionRunner.Action.Id),
-                // so two steps referencing the same Action.Id only ever
-                // register one Post. Mirror that here so we don't synthesize
-                // two placeholders for one future registration.
-                if (!seenActionIds.Add(action.Id))
-                {
-                    continue;
-                }
-
-                Definition definition;
-                try
-                {
-                    definition = actionManager.LoadAction(jobContext, action);
-                }
-                catch (Exception ex)
-                {
-                    Trace.Info($"DAP predictor: LoadAction failed for {repoRef.Name} ({ex.Message}); skipping prediction.");
-                    continue;
-                }
-
-                if (definition?.Data?.Execution?.HasPost != true)
-                {
-                    continue;
-                }
-
-                // Compute the Post display name exactly as ActionRunner does
-                // when it constructs the Post IActionRunner (ActionRunner.cs:115-122).
-                var displayName = runner.DisplayName;
-                if (string.IsNullOrEmpty(displayName))
-                {
-                    displayName = "step";
-                }
-                if (runner.Stage == ActionRunStage.Pre &&
-                    displayName.StartsWith("Pre ", StringComparison.OrdinalIgnoreCase))
-                {
-                    displayName = displayName.Substring("Pre ".Length);
-                }
-                var postDisplayName = $"Post {displayName}";
-
-                var entry = new JobExecutionViewEntry(
-                    phase: JobExecutionPhase.Post,
-                    displayName: postDisplayName,
-                    uses: StepEntryTranslator.FormatActionReference(action.Reference));
-
-                predictions.Add((entry, MatchKeyFor(action.Id)));
-            }
-
-            // Reverse declaration order so the rendered post section
-            // matches the LIFO order in which the runner will pop posts.
-            predictions.Reverse();
-
-            foreach (var (entry, key) in predictions)
-            {
-                try
-                {
-                    view.Append(entry, stepIdentity: null, matchKey: key);
-                }
-                catch (Exception ex)
-                {
-                    Trace.Warning("DAP predictor: failed to append Post placeholder; skipping.");
-                    Trace.Error(ex);
-                }
-            }
-        }
-
-        // Stable, opaque key derived from an action's Pipelines.ActionStep.Id.
-        // All IActionRunner instances for the same action (Pre/Main/Post)
-        // share the same Action reference (see ActionRunner.cs:131), so the
-        // Id is constant across phases and is the right join key.
-        private static string MatchKeyFor(Guid actionId) =>
-            $"post:{actionId:N}";
-
         internal async Task HandleMessageAsync(string messageJson, CancellationToken cancellationToken)
         {
             Request request = null;
@@ -785,8 +468,6 @@ namespace GitHub.Runner.Worker.Dap
                         "next" => HandleNext(request),
                         "setBreakpoints" => HandleSetBreakpoints(request),
                         "setExceptionBreakpoints" => HandleSetExceptionBreakpoints(request),
-                        "source" => HandleSource(request),
-                        "loadedSources" => HandleLoadedSources(request),
                         "completions" => HandleCompletions(request),
                         "stepIn" => CreateResponse(request, false, "Step In is not supported. Actions jobs debug at the step level - use 'next' to advance to the next step.", body: null),
                         "stepOut" => CreateResponse(request, false, "Step Out is not supported. Actions jobs debug at the step level - use 'continue' to resume.", body: null),
@@ -1174,7 +855,7 @@ namespace GitHub.Runner.Worker.Dap
 
         internal async Task OnStepStartingAsync(IStep step, bool isFirstStep)
         {
-            bool shouldPause;
+            bool pauseOnNextStep;
             CancellationToken cancellationToken;
             lock (_stateLock)
             {
@@ -1186,14 +867,18 @@ namespace GitHub.Runner.Worker.Dap
                 }
 
                 _currentStep = step;
+                _currentStepIndex = _completedSteps.Count;
+                pauseOnNextStep = _pauseOnNextStep;
                 cancellationToken = _jobContext?.CancellationToken ?? CancellationToken.None;
-                shouldPause = ShouldPauseBefore(step, isFirstStep);
             }
 
             // Reset variable references so stale nested refs from the
             // previous step are not served to the client.
             _variableProvider?.Reset();
 
+            // Determine if we should pause
+            bool shouldPause = isFirstStep || pauseOnNextStep;
+
             if (!shouldPause)
             {
                 Trace.Info("Step starting without debugger pause");
@@ -1217,29 +902,6 @@ namespace GitHub.Runner.Worker.Dap
             await WaitForCommandAsync(cancellationToken);
         }
 
-        /// <summary>
-        /// Decides whether the debugger should pause before <paramref name="step"/>.
-        /// Today: pause on the first step always; otherwise pause when the user
-        /// has elected step-mode (the 'next' command). Future breakpoint support
-        /// will be a single additional check here against a per-step breakpoint set.
-        /// Caller MUST hold <c>_stateLock</c>.
-        /// </summary>
-        private bool ShouldPauseBefore(IStep step, bool isFirstStep)
-        {
-            if (isFirstStep)
-            {
-                return true;
-            }
-
-            if (_pauseOnNextStep)
-            {
-                return true;
-            }
-
-            // TODO Phase 2c+1: if (_breakpointSet.Contains(step)) return true;
-            return false;
-        }
-
         internal void OnJobCompleted()
         {
             Trace.Info("Job completed, sending terminated event");
@@ -1311,7 +973,7 @@ namespace GitHub.Runner.Worker.Dap
                 SupportsTerminateRequest = false,
                 SupportTerminateDebuggee = false,
                 SupportsDelayedStackTraceLoading = false,
-                SupportsLoadedSourcesRequest = true,
+                SupportsLoadedSourcesRequest = false,
                 SupportsProgressReporting = false,
                 SupportsRunInTerminalRequest = false,
                 SupportsCancelRequest = false,
@@ -1385,171 +1047,72 @@ namespace GitHub.Runner.Worker.Dap
             return CreateResponse(request, true, body: body);
         }
 
-        internal Response HandleStackTrace(Request request)
+        private Response HandleStackTrace(Request request)
         {
             IStep currentStep;
-            JobExecutionView view;
-            bool jobCompleted;
+            int currentStepIndex;
+            CompletedStepInfo[] completedSteps;
             lock (_stateLock)
             {
                 currentStep = _currentStep;
-                view = _executionView;
-                jobCompleted = _jobCompleted;
+                currentStepIndex = _currentStepIndex;
+                completedSteps = _completedSteps.ToArray();
             }
 
             var frames = new List<StackFrame>();
 
-            if (view != null)
+            // Add current step as the top frame
+            if (currentStep != null)
             {
-                var source = BuildExecutionViewSource(view.JobId);
+                var resultIndicator = currentStep.ExecutionContext?.Result != null
+                    ? $" [{currentStep.ExecutionContext.Result}]"
+                    : " [running]";
 
-                if (jobCompleted)
-                {
-                    // Surface the synthetic Complete job step so the client
-                    // highlights the cleanup line at end-of-job pause.
-                    frames.Add(new StackFrame
-                    {
-                        Id = _currentFrameId,
-                        Name = MaskUserVisibleText("Complete job"),
-                        Line = view.CompleteJobLine,
-                        Column = 1,
-                        Source = source,
-                        PresentationHint = "normal",
-                    });
-                }
-                else if (currentStep != null)
-                {
-                    // Frame 0: the currently-executing step (only when one is set).
-                    var stepLine = view.TryGetLineForStep(currentStep) ?? 1;
-                    frames.Add(new StackFrame
-                    {
-                        Id = _currentFrameId,
-                        Name = MaskUserVisibleText(currentStep.DisplayName ?? "step"),
-                        Line = stepLine,
-                        Column = 1,
-                        Source = source,
-                        PresentationHint = "normal",
-                    });
-                }
-
-                // Frame 1: the job (anchors the stack; line 1 = the synthesized header).
-                frames.Add(new StackFrame
-                {
-                    Id = _jobFrameId,
-                    Name = MaskUserVisibleText($"job: {view.JobId}"),
-                    Line = 1,
-                    Column = 1,
-                    Source = source,
-                    PresentationHint = "subtle",
-                });
-            }
-            else if (currentStep != null)
-            {
-                // Defensive: view not yet built but a step is executing.
-                // Still emit a single frame with no Source so the client doesn't choke.
                 frames.Add(new StackFrame
                 {
                     Id = _currentFrameId,
-                    Name = MaskUserVisibleText(currentStep.DisplayName ?? "step"),
+                    Name = MaskUserVisibleText($"{currentStep.DisplayName ?? "Current Step"}{resultIndicator}"),
+                    Line = currentStepIndex + 1,
+                    Column = 1,
+                    PresentationHint = "normal"
+                });
+            }
+            else
+            {
+                frames.Add(new StackFrame
+                {
+                    Id = _currentFrameId,
+                    Name = "(no step executing)",
+                    Line = 0,
+                    Column = 1,
+                    PresentationHint = "subtle"
+                });
+            }
+
+            // Add completed steps as additional frames (most recent first)
+            for (int i = completedSteps.Length - 1; i >= 0; i--)
+            {
+                var completedStep = completedSteps[i];
+                var resultStr = completedStep.Result.HasValue ? $" [{completedStep.Result}]" : "";
+                frames.Add(new StackFrame
+                {
+                    Id = completedStep.FrameId,
+                    Name = MaskUserVisibleText($"{completedStep.DisplayName}{resultStr}"),
                     Line = 1,
                     Column = 1,
-                    PresentationHint = "normal",
+                    PresentationHint = "subtle"
                 });
             }
 
             var body = new StackTraceResponseBody
             {
                 StackFrames = frames,
-                TotalFrames = frames.Count,
+                TotalFrames = frames.Count
             };
 
             return CreateResponse(request, true, body: body);
         }
 
-        /// <summary>
-        /// Builds the synthesized job execution view <see cref="Source"/> descriptor.
-        /// All frames in a session share one Source; the client retrieves its
-        /// content via the DAP <c>source</c> request keyed by <see cref="_executionViewSourceReference"/>.
-        /// </summary>
-        private Source BuildExecutionViewSource(string jobId)
-        {
-            return new Source
-            {
-                Name = MaskUserVisibleText("execution.yml"),
-                Path = MaskUserVisibleText($"{jobId}/execution.yml"),
-                SourceReference = _executionViewSourceReference,
-                PresentationHint = "normal",
-            };
-        }
-
-        internal Response HandleSource(Request request)
-        {
-            SourceArguments args;
-            try
-            {
-                args = request.Arguments?.ToObject<SourceArguments>();
-            }
-            catch (Exception ex)
-            {
-                Trace.Warning($"Failed to parse source arguments: {ex.GetType().Name}");
-                return CreateResponse(request, false, "Invalid source arguments.", body: null);
-            }
-
-            if (args == null)
-            {
-                return CreateResponse(request, false, "Missing source arguments.", body: null);
-            }
-
-            JobExecutionView view;
-            lock (_stateLock)
-            {
-                view = _executionView;
-            }
-
-            if (view == null)
-            {
-                return CreateResponse(request, false, "Execution view not yet available.", body: null);
-            }
-
-            if (args.SourceReference != _executionViewSourceReference)
-            {
-                return CreateResponse(request, false, $"Unknown source reference: {args.SourceReference}.", body: null);
-            }
-
-            var body = new SourceResponseBody
-            {
-                Content = MaskUserVisibleText(view.Yaml),
-                // MimeType intentionally unset: VS Code's debug content provider
-                // short-circuits language detection on the response's mimeType
-                // (exact-match against its registered language mimetypes) and
-                // falls back to plaintext on unknown values. The IANA YAML type
-                // "application/yaml" is not in VS Code's table (it only knows
-                // the legacy "text/x-yaml" synthesized for the built-in YAML
-                // language contribution). By omitting mimeType, clients fall
-                // through to path-extension detection — `.yml` in Source.Path
-                // is the universal mechanism every DAP client honors
-                // consistently (VS Code, nvim-dap, JetBrains).
-            };
-
-            return CreateResponse(request, true, body: body);
-        }
-
-        internal Response HandleLoadedSources(Request request)
-        {
-            JobExecutionView view;
-            lock (_stateLock)
-            {
-                view = _executionView;
-            }
-
-            var body = new LoadedSourcesResponseBody();
-            if (view != null)
-            {
-                body.Sources.Add(BuildExecutionViewSource(view.JobId));
-            }
-            return CreateResponse(request, true, body: body);
-        }
-
         private Response HandleScopes(Request request)
         {
             var args = request.Arguments?.ToObject<ScopesArguments>();
@@ -1770,40 +1333,11 @@ namespace GitHub.Runner.Worker.Dap
             return CreateResponse(request, true, body: null);
         }
 
-        internal Response HandleSetBreakpoints(Request request)
+        private Response HandleSetBreakpoints(Request request)
         {
-            SetBreakpointsArguments args = null;
-            try
-            {
-                args = request.Arguments?.ToObject<SetBreakpointsArguments>();
-            }
-            catch (Exception ex)
-            {
-                Trace.Warning($"Failed to parse setBreakpoints arguments: {ex.GetType().Name}");
-            }
-
-            JobExecutionView view;
-            lock (_stateLock)
-            {
-                view = _executionView;
-            }
-
-            var body = new SetBreakpointsResponseBody();
-            if (args?.Breakpoints != null && view != null)
-            {
-                var source = BuildExecutionViewSource(view.JobId);
-                foreach (var requested in args.Breakpoints)
-                {
-                    body.Breakpoints.Add(new Breakpoint
-                    {
-                        Verified = false,
-                        Line = requested.Line,
-                        Source = source,
-                        Message = "Breakpoint support is coming in a future runner release. The debugger currently pauses at every step boundary; use 'continue' to advance.",
-                    });
-                }
-            }
-            return CreateResponse(request, true, body: body);
+            // MVP: acknowledge but don't process breakpoints
+            // All steps pause automatically via _pauseOnNextStep
+            return CreateResponse(request, true, body: new { breakpoints = Array.Empty<object>() });
         }
 
         private Response HandleSetExceptionBreakpoints(Request request)
@@ -1868,7 +1402,8 @@ namespace GitHub.Runner.Worker.Dap
 
         /// <summary>
         /// Resolves the execution context for a given stack frame ID.
-        /// Frame 1 = current step; frame 2 = job-level (subtle anchor frame).
+        /// Frame 1 = current step; frames 1000+ = completed steps (no
+        /// context available - those steps have already finished).
         /// Falls back to the job-level context when no step is active.
         /// </summary>
         private IExecutionContext GetExecutionContextForFrame(int frameId)
@@ -1878,7 +1413,7 @@ namespace GitHub.Runner.Worker.Dap
                 return GetCurrentExecutionContext();
             }
 
-            // Job/anchor frame — no step-level context.
+            // Completed-step frames don't carry a live execution context.
             return null;
         }
 
@@ -1949,33 +1484,6 @@ namespace GitHub.Runner.Worker.Dap
             SendOutput("console", $"\nCommands will run on {target}\n");
         }
 
-        /// <summary>
-        /// Sends a loadedSource event with the current execution view's source.
-        /// No-op if the view has not been built yet.
-        /// </summary>
-        private void SendLoadedSourceEvent(string reason)
-        {
-            JobExecutionView view;
-            lock (_stateLock)
-            {
-                view = _executionView;
-            }
-            if (view == null)
-            {
-                return;
-            }
-
-            SendEvent(new Event
-            {
-                EventType = "loadedSource",
-                Body = new LoadedSourceEventBody
-                {
-                    Reason = reason,
-                    Source = BuildExecutionViewSource(view.JobId),
-                },
-            });
-        }
-
         private string MaskUserVisibleText(string value)
         {
             if (string.IsNullOrEmpty(value))

src/Runner.Worker/Dap/DapMessages.cs

@@ -537,132 +537,6 @@ namespace GitHub.Runner.Worker.Dap
 
     #endregion
 
-    #region Source Request/Response
-
-    /// <summary>
-    /// Arguments for 'source' request.
-    /// </summary>
-    public class SourceArguments
-    {
-        /// <summary>
-        /// Source descriptor (optional, redundant with sourceReference).
-        /// </summary>
-        [JsonProperty("source", NullValueHandling = NullValueHandling.Ignore)]
-        public Source Source { get; set; }
-
-        /// <summary>
-        /// The reference to the source. Required by DAP spec.
-        /// </summary>
-        [JsonProperty("sourceReference")]
-        public int SourceReference { get; set; }
-    }
-
-    /// <summary>
-    /// Response body for 'source' request.
-    /// </summary>
-    public class SourceResponseBody
-    {
-        /// <summary>
-        /// Content of the source as a string.
-        /// </summary>
-        [JsonProperty("content")]
-        public string Content { get; set; }
-
-        /// <summary>
-        /// Optional content type / mime type of the source.
-        /// </summary>
-        [JsonProperty("mimeType", NullValueHandling = NullValueHandling.Ignore)]
-        public string MimeType { get; set; }
-    }
-
-    #endregion
-
-    #region LoadedSources Request/Response
-
-    /// <summary>
-    /// Response body for 'loadedSources' request.
-    /// </summary>
-    public class LoadedSourcesResponseBody
-    {
-        [JsonProperty("sources")]
-        public List<Source> Sources { get; set; } = new List<Source>();
-    }
-
-    /// <summary>
-    /// Body for 'loadedSource' event.
-    /// </summary>
-    public class LoadedSourceEventBody
-    {
-        /// <summary>
-        /// "new" | "changed" | "removed"
-        /// </summary>
-        [JsonProperty("reason")]
-        public string Reason { get; set; }
-
-        [JsonProperty("source")]
-        public Source Source { get; set; }
-    }
-
-    #endregion
-
-    #region SetBreakpoints Request/Response
-
-    /// <summary>
-    /// Arguments for 'setBreakpoints' request.
-    /// </summary>
-    public class SetBreakpointsArguments
-    {
-        [JsonProperty("source", NullValueHandling = NullValueHandling.Ignore)]
-        public Source Source { get; set; }
-
-        [JsonProperty("breakpoints")]
-        public List<SourceBreakpoint> Breakpoints { get; set; } = new List<SourceBreakpoint>();
-    }
-
-    /// <summary>
-    /// Properties of a breakpoint passed to the setBreakpoints request.
-    /// </summary>
-    public class SourceBreakpoint
-    {
-        [JsonProperty("line")]
-        public int Line { get; set; }
-
-        [JsonProperty("condition", NullValueHandling = NullValueHandling.Ignore)]
-        public string Condition { get; set; }
-
-        [JsonProperty("logMessage", NullValueHandling = NullValueHandling.Ignore)]
-        public string LogMessage { get; set; }
-    }
-
-    /// <summary>
-    /// Response body for 'setBreakpoints' request.
-    /// </summary>
-    public class SetBreakpointsResponseBody
-    {
-        [JsonProperty("breakpoints")]
-        public List<Breakpoint> Breakpoints { get; set; } = new List<Breakpoint>();
-    }
-
-    /// <summary>
-    /// Information about a breakpoint created in setBreakpoints.
-    /// </summary>
-    public class Breakpoint
-    {
-        [JsonProperty("verified")]
-        public bool Verified { get; set; }
-
-        [JsonProperty("line", NullValueHandling = NullValueHandling.Ignore)]
-        public int? Line { get; set; }
-
-        [JsonProperty("source", NullValueHandling = NullValueHandling.Ignore)]
-        public Source Source { get; set; }
-
-        [JsonProperty("message", NullValueHandling = NullValueHandling.Ignore)]
-        public string Message { get; set; }
-    }
-
-    #endregion
-
     #region Scopes Request/Response
 
     /// <summary>

src/Runner.Worker/Dap/IDapDebugger.cs

@@ -1,5 +1,4 @@
-using System.Collections.Generic;
-using System.Threading.Tasks;
+using System.Threading.Tasks;
 using GitHub.Runner.Common;
 
 namespace GitHub.Runner.Worker.Dap
@@ -22,23 +21,6 @@ namespace GitHub.Runner.Worker.Dap
         Task WaitUntilReadyAsync();
         Task OnStepStartingAsync(IStep step);
         void OnStepCompleted(IStep step);
-
-        /// <summary>
-        /// Called after JobExtension.InitializeJob has returned and the initial
-        /// step queue + post-step stack have been populated. The debugger uses
-        /// these snapshots to build the synthesized job execution view served
-        /// via the DAP source request.
-        /// </summary>
-        Task OnJobStepsInitializedAsync(IEnumerable<IStep> mainQueue, IEnumerable<IStep> initialPostStack);
-
-        /// <summary>
-        /// Called from ExecutionContext.RegisterPostJobStep after a post-step
-        /// is pushed onto the post-job stack. The debugger appends the step
-        /// to the running execution view so the rendered YAML reflects the
-        /// newly-known post-step.
-        /// </summary>
-        void OnPostStepRegistered(IStep step);
-
         Task OnJobCompletedAsync();
         Task StopAsync();
     }

src/Runner.Worker/Dap/JobExecutionView.cs

@@ -40,7 +40,6 @@ namespace GitHub.Runner.Worker.Dap
             new(StringComparer.Ordinal);
         private string _yaml;
         private IReadOnlyList<int> _entryStartLines = Array.Empty<int>();
-        private int _completeJobLine;
 
         public JobExecutionView(string jobId)
         {
@@ -73,21 +72,6 @@ namespace GitHub.Runner.Worker.Dap
             }
         }
 
-        /// <summary>
-        /// 1-based line where the synthetic <c>- step: Complete job</c> entry
-        /// appears in <see cref="Yaml"/>. Always non-zero — Cleanup is always emitted.
-        /// </summary>
-        public int CompleteJobLine
-        {
-            get
-            {
-                lock (_lock)
-                {
-                    return _completeJobLine;
-                }
-            }
-        }
-
         /// <summary>Number of entries (excludes synthetic Setup/Cleanup boundaries).</summary>
         public int EntryCount
         {
@@ -277,7 +261,6 @@ namespace GitHub.Runner.Worker.Dap
             var result = JobExecutionViewRenderer.Render(_jobId, _entries.AsReadOnly());
             _yaml = result.Yaml;
             _entryStartLines = result.EntryStartLines;
-            _completeJobLine = result.CompleteJobLine;
 
             _lineByStep.Clear();
             for (int i = 0; i < _stepIdentities.Count; i++)

src/Runner.Worker/Dap/JobExecutionViewRenderer.cs

@@ -95,21 +95,14 @@ namespace GitHub.Runner.Worker.Dap
     /// </summary>
     internal readonly struct RenderResult
     {
-        public RenderResult(string yaml, IReadOnlyList<int> entryStartLines, int completeJobLine)
+        public RenderResult(string yaml, IReadOnlyList<int> entryStartLines)
         {
             Yaml = yaml;
             EntryStartLines = entryStartLines;
-            CompleteJobLine = completeJobLine;
         }
 
         public string Yaml { get; }
         public IReadOnlyList<int> EntryStartLines { get; }
-
-        /// <summary>
-        /// 1-based line where the synthetic <c>- step: Complete job</c> entry
-        /// appears in <see cref="Yaml"/>. Always non-zero — Cleanup is always emitted.
-        /// </summary>
-        public int CompleteJobLine { get; }
     }
 
     /// <summary>
@@ -167,11 +160,9 @@ namespace GitHub.Runner.Worker.Dap
             // cleanup: section — always present, preceded by a blank line.
             sb.Append('\n');
             sb.Append("cleanup:\n");
-            newlinesEmitted += 2;
-            int completeJobLine = newlinesEmitted + 1;
             sb.Append("  - step: Complete job\n");
 
-            return new RenderResult(sb.ToString(), Array.AsReadOnly(startLines), completeJobLine);
+            return new RenderResult(sb.ToString(), Array.AsReadOnly(startLines));
         }
 
         private static void EmitPhaseSection(

src/Runner.Worker/ExecutionContext.cs

@@ -338,14 +338,6 @@ namespace GitHub.Runner.Worker
 
             step.ExecutionContext = Root.CreatePostChild(step.DisplayName, IntraActionState, siblingScopeName);
             Root.PostJobSteps.Push(step);
-            // Only consult the DAP debugger when it was actually enabled for this job.
-            // Without this guard, HostContext.GetService<IDapDebugger>() would auto-
-            // instantiate the default singleton for every non-debug job, violating the
-            // "no debugger, no risk" containment property.
-            if (Global.Debugger?.Enabled == true)
-            {
-                HostContext.GetService<Dap.IDapDebugger>().OnPostStepRegistered(step);
-            }
         }
 
         public IExecutionContext CreateChild(

src/Runner.Worker/Handlers/NodeScriptActionHandler.cs

@@ -12,7 +12,6 @@ using GitHub.Runner.Common.Util;
 using GitHub.Runner.Sdk;
 using GitHub.Runner.Worker.Container;
 using GitHub.Runner.Worker.Container.ContainerHooks;
-using GitHub.Services.Common;
 
 namespace GitHub.Runner.Worker.Handlers
 {
@@ -129,15 +128,6 @@ namespace GitHub.Runner.Worker.Handlers
             // file name character on Linux.
             string arguments = StepHost.ResolvePathForStepHost(ExecutionContext, StringUtil.Format(@"""{0}""", target.Replace(@"""", @"\""")));
 
-            // Disable maglev jit compiler in node.js 24.x.x on x64 Windows until the node.js bug is fixed.
-            // https://github.com/nodejs/node/issues/62260
-            if (nodeRuntimeVersion.StartsWith("node24", StringComparison.OrdinalIgnoreCase) &&
-                (StringUtil.ConvertToBoolean(System.Environment.GetEnvironmentVariable("ACTIONS_RUNNER_DISABLE_NODE_MAGLEV")) || StringUtil.ConvertToBoolean(Environment.GetValueOrDefault("ACTIONS_RUNNER_DISABLE_NODE_MAGLEV"))))
-            {
-                Trace.Info("Disable maglev jit compiler in node.js");
-                arguments = $"--no-maglev {arguments}";
-            }
-
 #if OS_WINDOWS
             // It appears that node.exe outputs UTF8 when not in TTY mode.
             Encoding outputEncoding = Encoding.UTF8;

src/Runner.Worker/JobRunner.cs

@@ -230,24 +230,6 @@ namespace GitHub.Runner.Worker
                         jobContext.JobSteps.Enqueue(step);
                     }
 
-                    if (jobContext.Global.Debugger?.Enabled == true)
-                    {
-                        // Only consult the DAP debugger when it was actually enabled for this job.
-                        // Without this guard, HostContext.GetService<IDapDebugger>() would auto-
-                        // instantiate the default singleton for every non-debug job, violating the
-                        // "no debugger, no risk" containment property.
-                        var dapDebugger = HostContext.GetService<Dap.IDapDebugger>();
-                        try
-                        {
-                            await dapDebugger.OnJobStepsInitializedAsync(jobContext.JobSteps, jobContext.PostJobSteps);
-                        }
-                        catch (Exception ex)
-                        {
-                            Trace.Warning("DAP OnJobStepsInitialized error; continuing without DAP view.");
-                            Trace.Error(ex);
-                        }
-                    }
-
                     await stepsRunner.RunAsync(jobContext);
                 }
                 catch (Exception ex)

src/Sdk/DTPipelines/workflow-v1.0.json

@@ -186,16 +186,7 @@
         "vars",
         "needs",
         "strategy",
-        "matrix",
-        "steps",
-        "job",
-        "runner",
-        "env",
-        "always(0,0)",
-        "failure(0,0)",
-        "cancelled(0,0)",
-        "success(0,0)",
-        "hashFiles(1,255)"
+        "matrix"
       ],
       "string": {}
     },

src/Sdk/WorkflowParser/Conversion/WorkflowTemplateConverter.cs

@@ -2291,10 +2291,6 @@ namespace GitHub.Actions.WorkflowParser.Conversion
             new NamedValueInfo<NoOperationNamedValue>(WorkflowTemplateConstants.Needs),
             new NamedValueInfo<NoOperationNamedValue>(WorkflowTemplateConstants.Strategy),
             new NamedValueInfo<NoOperationNamedValue>(WorkflowTemplateConstants.Matrix),
-            new NamedValueInfo<NoOperationNamedValue>(WorkflowTemplateConstants.Steps),
-            new NamedValueInfo<NoOperationNamedValue>(WorkflowTemplateConstants.Job),
-            new NamedValueInfo<NoOperationNamedValue>(WorkflowTemplateConstants.Runner),
-            new NamedValueInfo<NoOperationNamedValue>(WorkflowTemplateConstants.Env),
         };
         private static readonly IFunctionInfo[] s_jobConditionFunctions = new IFunctionInfo[]
         {
@@ -2311,13 +2307,6 @@ namespace GitHub.Actions.WorkflowParser.Conversion
             new FunctionInfo<NoOperation>(WorkflowTemplateConstants.Success, 0, 0),
             new FunctionInfo<NoOperation>(WorkflowTemplateConstants.HashFiles, 1, Byte.MaxValue),
         };
-        private static readonly IFunctionInfo[] s_snapshotConditionFunctions = new IFunctionInfo[]
-        {
-            new FunctionInfo<NoOperation>(WorkflowTemplateConstants.Always, 0, 0),
-            new FunctionInfo<NoOperation>(WorkflowTemplateConstants.Cancelled, 0, 0),
-            new FunctionInfo<NoOperation>(WorkflowTemplateConstants.Failure, 0, 0),
-            new FunctionInfo<NoOperation>(WorkflowTemplateConstants.Success, 0, 0),
-            new FunctionInfo<NoOperation>(WorkflowTemplateConstants.HashFiles, 1, Byte.MaxValue),
-        };
+        private static readonly IFunctionInfo[] s_snapshotConditionFunctions = null;
     }
 }

src/Sdk/WorkflowParser/workflow-v1.0.json

@@ -2196,16 +2196,7 @@
         "vars",
         "needs",
         "strategy",
-        "matrix",
-        "steps",
-        "job",
-        "runner",
-        "env",
-        "always(0,0)",
-        "failure(0,0)",
-        "cancelled(0,0)",
-        "success(0,0)",
-        "hashFiles(1,255)"
+        "matrix"
       ],
       "description": "Use the if conditional to prevent a snapshot from being taken unless a condition is met. Any supported context and expression can be used to create a conditional. Expressions in an `if` conditional do not require the bracketed expression syntax. When you use expressions in an `if` conditional, you may omit the expression syntax because GitHub automatically evaluates the `if` conditional as an expression.",
       "string": {

src/Test/L0/Worker/DapDebuggerL0.cs

@@ -1090,576 +1090,5 @@ namespace GitHub.Runner.Common.Tests.Worker
                 await _debugger.StopAsync();
             }
         }
-
-        // ---------------------------------------------------------------------
-        // Phase 2c: synthesized execution view as DAP source.
-        // ---------------------------------------------------------------------
-
-        private static Mock<GitHub.Runner.Worker.IActionRunner> NewActionRunner(
-            GitHub.Runner.Worker.ActionRunStage stage,
-            string displayName,
-            string actionName = "actions/checkout",
-            string actionRef = "v4")
-        {
-            var mock = new Mock<GitHub.Runner.Worker.IActionRunner>();
-            mock.SetupGet(x => x.Stage).Returns(stage);
-            mock.SetupGet(x => x.DisplayName).Returns(displayName);
-            mock.SetupGet(x => x.Action).Returns(new GitHub.DistributedTask.Pipelines.ActionStep
-            {
-                Reference = new GitHub.DistributedTask.Pipelines.RepositoryPathReference
-                {
-                    Name = actionName,
-                    Ref = actionRef,
-                },
-            });
-            return mock;
-        }
-
-        private async Task DriveDebuggerToReadyAsync(int port)
-        {
-            var waitTask = _debugger.WaitUntilReadyAsync();
-            var client = new TcpClient();
-            await client.ConnectAsync(IPAddress.Loopback, port);
-            var stream = client.GetStream();
-            await SendRequestAsync(stream, new Request
-            {
-                Seq = 1,
-                Type = "request",
-                Command = "configurationDone",
-            });
-            await waitTask;
-            // Hold the client alive via GC root in caller scope through field.
-            _liveDriveClient = client;
-        }
-
-        private TcpClient _liveDriveClient;
-
-        private static Request MakeRequest(string command, object args = null)
-        {
-            return new Request
-            {
-                Seq = 1,
-                Type = "request",
-                Command = command,
-                Arguments = args == null ? null : Newtonsoft.Json.Linq.JObject.FromObject(args),
-            };
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task HandleSource_ReturnsExecutionViewYaml()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    var step = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Run").Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { step }, Array.Empty<IStep>());
-
-                    var response = _debugger.HandleSource(MakeRequest("source", new SourceArguments { SourceReference = 1 }));
-                    Assert.True(response.Success);
-                    var body = Assert.IsType<SourceResponseBody>(response.Body);
-                    Assert.Equal(_debugger.ExecutionView.Yaml, body.Content);
-                    Assert.Null(body.MimeType);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task HandleSource_UnknownReference_Fails()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    var step = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Run").Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { step }, Array.Empty<IStep>());
-
-                    var response = _debugger.HandleSource(MakeRequest("source", new SourceArguments { SourceReference = 999 }));
-                    Assert.False(response.Success);
-                    Assert.Contains("Unknown source reference", response.Message);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task HandleSource_NoView_Fails()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    // No OnJobStepsInitializedAsync call — view is null.
-                    var response = _debugger.HandleSource(MakeRequest("source", new SourceArguments { SourceReference = 1 }));
-                    Assert.False(response.Success);
-                    Assert.Contains("Execution view not yet available", response.Message);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task HandleSource_OmitsMimeType()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    var step = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Run").Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { step }, Array.Empty<IStep>());
-
-                    var response = _debugger.HandleSource(MakeRequest("source", new SourceArguments { SourceReference = 1 }));
-                    Assert.True(response.Success);
-                    var body = Assert.IsType<SourceResponseBody>(response.Body);
-                    // MimeType is intentionally omitted so DAP clients fall through
-                    // to path-extension detection (`.yml`) — the most consistently
-                    // honored mechanism across VS Code, nvim-dap, and JetBrains.
-                    Assert.Null(body.MimeType);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task HandleSource_MasksSecrets()
-        {
-            const string Secret = "supersecret-shhh-value";
-            using (var hc = CreateTestContext())
-            {
-                hc.SecretMasker.AddValue(Secret);
-
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    // Embed the secret in a step display name so it ends up in the rendered YAML.
-                    var step = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, $"Run {Secret} step").Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { step }, Array.Empty<IStep>());
-
-                    // Sanity-check the raw view actually contains the secret;
-                    // otherwise the masking assertion below would pass vacuously.
-                    Assert.Contains(Secret, _debugger.ExecutionView.Yaml);
-
-                    var response = _debugger.HandleSource(MakeRequest("source", new SourceArguments { SourceReference = 1 }));
-                    Assert.True(response.Success);
-                    var body = Assert.IsType<SourceResponseBody>(response.Body);
-                    Assert.DoesNotContain(Secret, body.Content);
-                    Assert.Contains("***", body.Content);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task HandleStackTrace_MasksSecretsInSourcePath()
-        {
-            const string Secret = "secret-job-name-xyz";
-            using (var hc = CreateTestContext())
-            {
-                hc.SecretMasker.AddValue(Secret);
-
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                // Job name (== GitHub context "job") embeds the secret.
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, Secret);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    var step = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Run").Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { step }, Array.Empty<IStep>());
-
-                    _ = _debugger.OnStepStartingAsync(step, isFirstStep: false);
-                    await Task.Delay(50);
-
-                    var response = _debugger.HandleStackTrace(MakeRequest("stackTrace"));
-                    var body = Assert.IsType<StackTraceResponseBody>(response.Body);
-                    Assert.NotEmpty(body.StackFrames);
-                    foreach (var frame in body.StackFrames)
-                    {
-                        if (frame.Source != null)
-                        {
-                            Assert.DoesNotContain(Secret, frame.Source.Path ?? string.Empty);
-                            Assert.DoesNotContain(Secret, frame.Source.Name ?? string.Empty);
-                            Assert.Contains("***", frame.Source.Path ?? string.Empty);
-                        }
-                        Assert.DoesNotContain(Secret, frame.Name ?? string.Empty);
-                    }
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task HandleStackTrace_TwoFramesWhenStepping()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    var step1 = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Step One").Object;
-                    var step2 = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Step Two", "actions/setup-node", "v3").Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { step1, step2 }, Array.Empty<IStep>());
-
-                    // Fire-and-forget: first step pauses, but we just want _currentStep set.
-                    _ = _debugger.OnStepStartingAsync(step1, isFirstStep: false);
-                    await Task.Delay(50);
-
-                    var response = _debugger.HandleStackTrace(MakeRequest("stackTrace"));
-                    var body = Assert.IsType<StackTraceResponseBody>(response.Body);
-                    Assert.Equal(2, body.StackFrames.Count);
-
-                    var frame0 = body.StackFrames[0];
-                    Assert.Equal(1, frame0.Source.SourceReference);
-                    Assert.Equal(_debugger.ExecutionView.TryGetLineForStep(step1), frame0.Line);
-                    Assert.Equal("normal", frame0.PresentationHint);
-
-                    var frame1 = body.StackFrames[1];
-                    Assert.Equal(1, frame1.Line);
-                    Assert.Equal("subtle", frame1.PresentationHint);
-                    Assert.Equal(1, frame1.Source.SourceReference);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task HandleStackTrace_OneFrameWhenViewMissing()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    var step = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Lonely").Object;
-                    // No view built — but pause the step so _currentStep is set.
-                    _ = _debugger.OnStepStartingAsync(step, isFirstStep: false);
-                    await Task.Delay(50);
-
-                    var response = _debugger.HandleStackTrace(MakeRequest("stackTrace"));
-                    var body = Assert.IsType<StackTraceResponseBody>(response.Body);
-                    Assert.Single(body.StackFrames);
-                    Assert.Null(body.StackFrames[0].Source);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task HandleStackTrace_NoFramesWhenIdle()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    var response = _debugger.HandleStackTrace(MakeRequest("stackTrace"));
-                    var body = Assert.IsType<StackTraceResponseBody>(response.Body);
-                    Assert.Empty(body.StackFrames);
-                    Assert.Equal(0, body.TotalFrames);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task HandleLoadedSources_ReturnsExecutionView()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    var step = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Run").Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { step }, Array.Empty<IStep>());
-
-                    var response = _debugger.HandleLoadedSources(MakeRequest("loadedSources"));
-                    Assert.True(response.Success);
-                    var body = Assert.IsType<LoadedSourcesResponseBody>(response.Body);
-                    Assert.Single(body.Sources);
-                    Assert.Equal("execution.yml", body.Sources[0].Name);
-                    Assert.Equal("ci-job/execution.yml", body.Sources[0].Path);
-                    Assert.Equal(1, body.Sources[0].SourceReference);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task HandleLoadedSources_NoView_ReturnsEmpty()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    var response = _debugger.HandleLoadedSources(MakeRequest("loadedSources"));
-                    Assert.True(response.Success);
-                    var body = Assert.IsType<LoadedSourcesResponseBody>(response.Body);
-                    Assert.Empty(body.Sources);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task HandleSetBreakpoints_ReturnsUnverifiedPlaceholders()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    var step = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Run").Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { step }, Array.Empty<IStep>());
-
-                    var args = new SetBreakpointsArguments
-                    {
-                        Source = new Source { SourceReference = 1 },
-                        Breakpoints = new System.Collections.Generic.List<SourceBreakpoint>
-                        {
-                            new SourceBreakpoint { Line = 5 },
-                            new SourceBreakpoint { Line = 10 },
-                            new SourceBreakpoint { Line = 15 },
-                        },
-                    };
-
-                    var response = _debugger.HandleSetBreakpoints(MakeRequest("setBreakpoints", args));
-                    Assert.True(response.Success);
-                    var body = Assert.IsType<SetBreakpointsResponseBody>(response.Body);
-                    Assert.Equal(3, body.Breakpoints.Count);
-                    Assert.All(body.Breakpoints, bp => Assert.False(bp.Verified));
-                    Assert.Equal(new[] { 5, 10, 15 }, body.Breakpoints.ConvertAll(b => b.Line ?? -1));
-                    Assert.All(body.Breakpoints, bp => Assert.False(string.IsNullOrEmpty(bp.Message)));
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnJobStepsInitialized_EmitsLoadedSourceNewEvent()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                using var client = await ConnectClientAsync(port);
-                try
-                {
-                    var stream = client.GetStream();
-                    await SendRequestAsync(stream, new Request { Seq = 1, Type = "request", Command = "configurationDone" });
-                    await ReadDapMessageAsync(stream, TimeSpan.FromSeconds(5)); // configurationDone response
-                    await ReadDapMessageAsync(stream, TimeSpan.FromSeconds(5)); // welcome output event
-                    await _debugger.WaitUntilReadyAsync();
-
-                    var step = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Run").Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { step }, Array.Empty<IStep>());
-
-                    var msg = await ReadDapMessageAsync(stream, TimeSpan.FromSeconds(5));
-                    Assert.Contains("\"event\":\"loadedSource\"", msg);
-                    Assert.Contains("\"reason\":\"new\"", msg);
-                    Assert.Contains("\"sourceReference\":1", msg);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnPostStepRegistered_EmitsLoadedSourceChangedEvent()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                using var client = await ConnectClientAsync(port);
-                try
-                {
-                    var stream = client.GetStream();
-                    await SendRequestAsync(stream, new Request { Seq = 1, Type = "request", Command = "configurationDone" });
-                    await ReadDapMessageAsync(stream, TimeSpan.FromSeconds(5)); // configurationDone response
-                    await ReadDapMessageAsync(stream, TimeSpan.FromSeconds(5)); // welcome output event
-                    await _debugger.WaitUntilReadyAsync();
-
-                    var main = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Run").Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { main }, Array.Empty<IStep>());
-                    // Drain the "new" loadedSource event.
-                    await ReadDapMessageAsync(stream, TimeSpan.FromSeconds(5));
-
-                    var post = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Post, "Post Run", "actions/cache", "v3").Object;
-                    _debugger.OnPostStepRegistered(post);
-
-                    var msg = await ReadDapMessageAsync(stream, TimeSpan.FromSeconds(5));
-                    Assert.Contains("\"event\":\"loadedSource\"", msg);
-                    Assert.Contains("\"reason\":\"changed\"", msg);
-                    Assert.Contains("\"sourceReference\":1", msg);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task StackTrace_LineUpdatesAsStepsAdvance()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port, "ci-job");
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveDebuggerToReadyAsync(port);
-                    var s1 = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Step 1", "a/b", "v1").Object;
-                    var s2 = NewActionRunner(GitHub.Runner.Worker.ActionRunStage.Main, "Step 2", "c/d", "v2").Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { s1, s2 }, Array.Empty<IStep>());
-
-                    _ = _debugger.OnStepStartingAsync(s1, isFirstStep: true);
-                    await Task.Delay(50);
-
-                    var first = _debugger.HandleStackTrace(MakeRequest("stackTrace"));
-                    var firstBody = Assert.IsType<StackTraceResponseBody>(first.Body);
-                    int firstLine = firstBody.StackFrames[0].Line;
-                    Assert.Equal(_debugger.ExecutionView.TryGetLineForStep(s1), firstLine);
-
-                    _ = _debugger.OnStepStartingAsync(s2, isFirstStep: false);
-                    await Task.Delay(50);
-
-                    var second = _debugger.HandleStackTrace(MakeRequest("stackTrace"));
-                    var secondBody = Assert.IsType<StackTraceResponseBody>(second.Body);
-                    int secondLine = secondBody.StackFrames[0].Line;
-                    Assert.Equal(_debugger.ExecutionView.TryGetLineForStep(s2), secondLine);
-                    Assert.NotEqual(firstLine, secondLine);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
     }
 }

src/Test/L0/Worker/ExecutionContextL0.cs

@@ -7,7 +7,6 @@ using GitHub.DistributedTask.Pipelines.ContextData;
 using GitHub.DistributedTask.WebApi;
 using GitHub.Runner.Worker;
 using GitHub.Runner.Worker.Container;
-using GitHub.Runner.Worker.Dap;
 using GitHub.Runner.Worker.Handlers;
 using Moq;
 using Xunit;
@@ -406,7 +405,6 @@ namespace GitHub.Runner.Common.Tests.Worker
                 hc.EnqueueInstance(pagingLogger5.Object);
                 hc.EnqueueInstance(actionRunner1 as IActionRunner);
                 hc.EnqueueInstance(actionRunner2 as IActionRunner);
-                hc.SetSingleton(new Mock<IDapDebugger>().Object);
                 hc.SetSingleton(jobServerQueue.Object);
 
                 var jobContext = new Runner.Worker.ExecutionContext();
@@ -505,7 +503,6 @@ namespace GitHub.Runner.Common.Tests.Worker
                 hc.EnqueueInstance(pagingLogger5.Object);
                 hc.EnqueueInstance(actionRunner1 as IActionRunner);
                 hc.EnqueueInstance(actionRunner2 as IActionRunner);
-                hc.SetSingleton(new Mock<IDapDebugger>().Object);
                 hc.SetSingleton(jobServerQueue.Object);
 
                 var jobContext = new Runner.Worker.ExecutionContext();
@@ -547,75 +544,6 @@ namespace GitHub.Runner.Common.Tests.Worker
             }
         }
 
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public void RegisterPostJobAction_DebuggerDisabled_DoesNotInvokeDapDebugger()
-        {
-            using (TestHostContext hc = CreateTestContext())
-            {
-                // Arrange: Create a job request message with EnableDebugger left at the default (false).
-                TaskOrchestrationPlanReference plan = new();
-                TimelineReference timeline = new();
-                Guid jobId = Guid.NewGuid();
-                string jobName = "some job name";
-                var jobRequest = new Pipelines.AgentJobRequestMessage(plan, timeline, jobId, jobName, jobName, null, null, null, new Dictionary<string, VariableValue>(), new List<MaskHint>(), new Pipelines.JobResources(), new Pipelines.ContextData.DictionaryContextData(), new Pipelines.WorkspaceOptions(), new List<Pipelines.ActionStep>(), null, null, null, null, null);
-                jobRequest.Resources.Repositories.Add(new Pipelines.RepositoryResource()
-                {
-                    Alias = Pipelines.PipelineConstants.SelfAlias,
-                    Id = "github",
-                    Version = "sha1"
-                });
-                jobRequest.ContextData["github"] = new Pipelines.ContextData.DictionaryContextData();
-
-                var pagingLogger = new Mock<IPagingLogger>();
-                var jobServerQueue = new Mock<IJobServerQueue>();
-                jobServerQueue.Setup(x => x.QueueTimelineRecordUpdate(It.IsAny<Guid>(), It.IsAny<TimelineRecord>()));
-                jobServerQueue.Setup(x => x.QueueWebConsoleLine(It.IsAny<Guid>(), It.IsAny<string>(), It.IsAny<long?>()));
-
-                var actionRunner = new ActionRunner();
-                actionRunner.Initialize(hc);
-
-                hc.EnqueueInstance(pagingLogger.Object);
-                hc.EnqueueInstance(pagingLogger.Object);
-                hc.EnqueueInstance(pagingLogger.Object);
-                hc.EnqueueInstance(pagingLogger.Object);
-                hc.EnqueueInstance(pagingLogger.Object);
-                hc.EnqueueInstance(pagingLogger.Object);
-                hc.EnqueueInstance(pagingLogger.Object);
-                hc.EnqueueInstance(actionRunner as IActionRunner);
-
-                // Register a strict mock IDapDebugger. If the production code calls
-                // ANY method on it, the test fails — proving the containment guard
-                // short-circuited before HostContext.GetService<IDapDebugger>().
-                var dapMock = new Mock<IDapDebugger>(MockBehavior.Strict);
-                hc.SetSingleton(dapMock.Object);
-                hc.SetSingleton(jobServerQueue.Object);
-
-                var jobContext = new Runner.Worker.ExecutionContext();
-                jobContext.Initialize(hc);
-                jobContext.InitializeJob(jobRequest, CancellationToken.None);
-
-                var action = jobContext.CreateChild(Guid.NewGuid(), "action_1", "action_1", null, null, 0);
-
-                var postRunner = hc.CreateService<IActionRunner>();
-                postRunner.Action = new Pipelines.ActionStep() { Id = Guid.NewGuid(), Name = "post", DisplayName = "Post", Reference = new Pipelines.RepositoryPathReference() { Name = "actions/action" } };
-                postRunner.Stage = ActionRunStage.Post;
-                postRunner.Condition = "always()";
-                postRunner.DisplayName = "post";
-
-                // Sanity: ensure the production code path actually believes the debugger is disabled.
-                Assert.True(jobContext.Global.Debugger == null || jobContext.Global.Debugger.Enabled == false);
-
-                // Act.
-                action.RegisterPostJobStep(postRunner);
-
-                // Assert: the debugger was never consulted on the non-debug path.
-                dapMock.VerifyNoOtherCalls();
-                Assert.Equal(1, jobContext.PostJobSteps.Count);
-            }
-        }
-
         [Fact]
         [Trait("Level", "L0")]
         [Trait("Category", "Worker")]

src/Test/L0/Worker/JobExecutionViewLifecycleL0.cs

@@ -1,660 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Net;
-using System.Net.Sockets;
-using System.Runtime.CompilerServices;
-using System.Text;
-using System.Threading;
-using System.Threading.Tasks;
-using GitHub.DistributedTask.Pipelines;
-using GitHub.DistributedTask.WebApi;
-using GitHub.Runner.Worker;
-using GitHub.Runner.Worker.Dap;
-using Moq;
-using Newtonsoft.Json;
-using Xunit;
-
-namespace GitHub.Runner.Common.Tests.Worker
-{
-    public sealed class JobExecutionViewLifecycleL0
-    {
-        private DapDebugger _debugger;
-
-        private TestHostContext CreateTestContext([CallerMemberName] string testName = "")
-        {
-            var hc = new TestHostContext(this, testName);
-            _debugger = new DapDebugger();
-            _debugger.Initialize(hc);
-            _debugger.SkipTunnelRelay = true;
-            _debugger.SkipWebSocketBridge = true;
-            return hc;
-        }
-
-        private static ushort GetFreePort()
-        {
-            using var listener = new TcpListener(IPAddress.Loopback, 0);
-            listener.Start();
-            return (ushort)((IPEndPoint)listener.LocalEndpoint).Port;
-        }
-
-        private static Mock<IExecutionContext> CreateJobContextWithTunnel(CancellationToken cancellationToken, ushort port, string jobName = "ci-job")
-        {
-            var tunnel = new GitHub.DistributedTask.Pipelines.DebuggerTunnelInfo
-            {
-                TunnelId = "test-tunnel",
-                ClusterId = "test-cluster",
-                HostToken = "test-token",
-                Port = port
-            };
-            var debuggerConfig = new DebuggerConfig(true, tunnel);
-            var jobContext = new Mock<IExecutionContext>();
-            jobContext.Setup(x => x.CancellationToken).Returns(cancellationToken);
-            jobContext.Setup(x => x.Global).Returns(new GlobalContext { Debugger = debuggerConfig });
-            jobContext
-                .Setup(x => x.GetGitHubContext(It.IsAny<string>()))
-                .Returns((string contextName) => string.Equals(contextName, "job", StringComparison.Ordinal) ? jobName : null);
-            return jobContext;
-        }
-
-        private static async Task DriveToReadyAsync(DapDebugger debugger, int port)
-        {
-            var waitTask = debugger.WaitUntilReadyAsync();
-            var client = new TcpClient();
-            await client.ConnectAsync(IPAddress.Loopback, port);
-            var stream = client.GetStream();
-            var request = new Request { Seq = 1, Type = "request", Command = "configurationDone" };
-            var json = JsonConvert.SerializeObject(request);
-            var body = Encoding.UTF8.GetBytes(json);
-            var header = Encoding.ASCII.GetBytes($"Content-Length: {body.Length}\r\n\r\n");
-            await stream.WriteAsync(header, 0, header.Length);
-            await stream.WriteAsync(body, 0, body.Length);
-            await stream.FlushAsync();
-            await waitTask;
-            // Keep client alive by holding a reference via GC root in caller scope.
-            // We deliberately don't dispose here; tests dispose the context.
-            _ = client;
-        }
-
-        private static Mock<IActionRunner> NewActionRunner(ActionRunStage stage, string displayName, string actionName = "actions/checkout", string actionRef = "v4", Guid actionId = default)
-        {
-            var mock = new Mock<IActionRunner>();
-            mock.SetupGet(x => x.Stage).Returns(stage);
-            mock.SetupGet(x => x.DisplayName).Returns(displayName);
-            mock.SetupGet(x => x.Action).Returns(new ActionStep
-            {
-                Id = actionId,
-                Reference = new RepositoryPathReference { Name = actionName, Ref = actionRef },
-            });
-            return mock;
-        }
-
-        private static Mock<IActionRunner> NewSelfActionRunner(ActionRunStage stage, string displayName, Guid actionId = default)
-        {
-            // RepositoryType = "self" — the predictor must skip these.
-            var mock = new Mock<IActionRunner>();
-            mock.SetupGet(x => x.Stage).Returns(stage);
-            mock.SetupGet(x => x.DisplayName).Returns(displayName);
-            mock.SetupGet(x => x.Action).Returns(new ActionStep
-            {
-                Id = actionId,
-                Reference = new RepositoryPathReference
-                {
-                    RepositoryType = GitHub.DistributedTask.Pipelines.PipelineConstants.SelfAlias,
-                    Path = "./.github/actions/local",
-                },
-            });
-            return mock;
-        }
-
-        private static Mock<IActionRunner> NewScriptActionRunner(ActionRunStage stage, string displayName, Guid actionId = default)
-        {
-            // ScriptReference — a `run:` step. Not a RepositoryPathReference,
-            // so the predictor's pattern match falls through.
-            var mock = new Mock<IActionRunner>();
-            mock.SetupGet(x => x.Stage).Returns(stage);
-            mock.SetupGet(x => x.DisplayName).Returns(displayName);
-            mock.SetupGet(x => x.Action).Returns(new ActionStep
-            {
-                Id = actionId,
-                Reference = new ScriptReference(),
-            });
-            return mock;
-        }
-
-        // IActionManager mock that returns specific Definitions per action by
-        // matching on the action's reference Name. Actions whose name is not
-        // in the map get a Definition with HasPost = false.
-        private static Mock<IActionManager> NewActionManagerWithPost(params string[] actionNamesWithPost)
-        {
-            var withPost = new HashSet<string>(actionNamesWithPost, StringComparer.Ordinal);
-            var mock = new Mock<IActionManager>();
-            mock.Setup(x => x.LoadAction(It.IsAny<IExecutionContext>(), It.IsAny<ActionStep>()))
-                .Returns((IExecutionContext _, ActionStep step) =>
-                {
-                    var name = (step.Reference as RepositoryPathReference)?.Name ?? "";
-                    return new Definition
-                    {
-                        Data = new ActionDefinitionData
-                        {
-                            Execution = withPost.Contains(name)
-                                ? new NodeJSActionExecutionData { Post = "post.js" }
-                                : new NodeJSActionExecutionData(),
-                        },
-                    };
-                });
-            return mock;
-        }
-
-        private static IStep NewJobExtensionRunner(string displayName)
-        {
-            return new JobExtensionRunner(
-                runAsync: (_, __) => Task.CompletedTask,
-                condition: null,
-                displayName: displayName,
-                data: null);
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnJobStepsInitialized_NotActive_NoOps()
-        {
-            using (CreateTestContext())
-            {
-                var step = NewActionRunner(ActionRunStage.Main, "Run").Object;
-
-                await _debugger.OnJobStepsInitializedAsync(new[] { step }, Array.Empty<IStep>());
-
-                Assert.Null(_debugger.ExecutionView);
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnPostStepRegistered_NotActive_NoOps()
-        {
-            using (CreateTestContext())
-            {
-                var step = NewActionRunner(ActionRunStage.Post, "Post Run").Object;
-                _debugger.OnPostStepRegistered(step); // must not throw
-                Assert.Null(_debugger.ExecutionView);
-                await Task.CompletedTask;
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnJobStepsInitialized_Active_BuildsView()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-
-                    var main1 = NewActionRunner(ActionRunStage.Main, "Run actions/checkout@v4").Object;
-                    var main2 = NewActionRunner(ActionRunStage.Main, "Run actions/setup-node@v3", "actions/setup-node", "v3").Object;
-                    var jobExt = NewJobExtensionRunner("Set up job");
-                    var post1 = NewActionRunner(ActionRunStage.Post, "Post Run actions/checkout@v4").Object;
-
-                    await _debugger.OnJobStepsInitializedAsync(
-                        new IStep[] { main1, jobExt, main2 },
-                        new IStep[] { post1 });
-
-                    var view = _debugger.ExecutionView;
-                    Assert.NotNull(view);
-                    Assert.Equal(3, view.EntryCount); // jobExt filtered out
-                    Assert.Contains("Run actions/checkout@v4", view.Yaml);
-                    Assert.Contains("Run actions/setup-node@v3", view.Yaml);
-                    Assert.Contains("Post Run actions/checkout@v4", view.Yaml);
-                    Assert.NotNull(view.TryGetLineForStep(main1));
-                    Assert.NotNull(view.TryGetLineForStep(main2));
-                    Assert.NotNull(view.TryGetLineForStep(post1));
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnJobStepsInitialized_PreservesQueueOrder()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-
-                    var s1 = NewActionRunner(ActionRunStage.Main, "Step 1", "a/b", "v1").Object;
-                    var s2 = NewActionRunner(ActionRunStage.Main, "Step 2", "c/d", "v2").Object;
-                    var s3 = NewActionRunner(ActionRunStage.Main, "Step 3", "e/f", "v3").Object;
-
-                    await _debugger.OnJobStepsInitializedAsync(new[] { s1, s2, s3 }, Array.Empty<IStep>());
-
-                    var view = _debugger.ExecutionView;
-                    Assert.Equal(3, view.EntryCount);
-                    var l1 = view.TryGetLineForStep(s1);
-                    var l2 = view.TryGetLineForStep(s2);
-                    var l3 = view.TryGetLineForStep(s3);
-                    Assert.NotNull(l1);
-                    Assert.NotNull(l2);
-                    Assert.NotNull(l3);
-                    Assert.True(l1 < l2);
-                    Assert.True(l2 < l3);
-                    Assert.Equal(view.GetLine(0), l1);
-                    Assert.Equal(view.GetLine(1), l2);
-                    Assert.Equal(view.GetLine(2), l3);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnPostStepRegistered_AppendsToView()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-
-                    var main1 = NewActionRunner(ActionRunStage.Main, "Run actions/checkout@v4").Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { main1 }, Array.Empty<IStep>());
-                    Assert.Equal(1, _debugger.ExecutionView.EntryCount);
-
-                    var post1 = NewActionRunner(ActionRunStage.Post, "Post Run actions/cache@v3", "actions/cache", "v3").Object;
-                    _debugger.OnPostStepRegistered(post1);
-
-                    var view = _debugger.ExecutionView;
-                    Assert.Equal(2, view.EntryCount);
-                    Assert.Contains("Post Run actions/cache@v3", view.Yaml);
-                    Assert.NotNull(view.TryGetLineForStep(post1));
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnPostStepRegistered_BeforeViewBuilt_NoOps()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-
-                    var post = NewActionRunner(ActionRunStage.Post, "Post Run").Object;
-                    _debugger.OnPostStepRegistered(post); // must not throw
-
-                    Assert.Null(_debugger.ExecutionView);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnPostStepRegistered_DuplicateStep_DoesNotThrow()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-                    await _debugger.OnJobStepsInitializedAsync(Array.Empty<IStep>(), Array.Empty<IStep>());
-
-                    var post = NewActionRunner(ActionRunStage.Post, "Post Run").Object;
-                    _debugger.OnPostStepRegistered(post);
-                    _debugger.OnPostStepRegistered(post); // duplicate, must be silently ignored
-
-                    Assert.Equal(1, _debugger.ExecutionView.EntryCount);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnPostStepRegistered_FilteredStep_NoOps()
-        {
-            using (CreateTestContext())
-            {
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-                    await _debugger.OnJobStepsInitializedAsync(Array.Empty<IStep>(), Array.Empty<IStep>());
-
-                    var before = _debugger.ExecutionView.EntryCount;
-                    _debugger.OnPostStepRegistered(NewJobExtensionRunner("Cleanup"));
-                    Assert.Equal(before, _debugger.ExecutionView.EntryCount);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        // ---- Predictive Post-step synthesis ----
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnJobStepsInitialized_PredictsPostForActionsWithHasPost()
-        {
-            using (var hc = CreateTestContext())
-            {
-                hc.SetSingleton<IActionManager>(NewActionManagerWithPost("actions/has-post").Object);
-
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-
-                    var withPost = NewActionRunner(ActionRunStage.Main, "Run actions/has-post@v1", "actions/has-post", "v1", actionId: Guid.NewGuid()).Object;
-                    var noPost = NewActionRunner(ActionRunStage.Main, "Run actions/no-post@v1", "actions/no-post", "v1", actionId: Guid.NewGuid()).Object;
-
-                    await _debugger.OnJobStepsInitializedAsync(new[] { withPost, noPost }, Array.Empty<IStep>());
-
-                    var view = _debugger.ExecutionView;
-                    Assert.NotNull(view);
-                    // 2 main entries + 1 predicted post placeholder.
-                    Assert.Equal(3, view.EntryCount);
-                    Assert.Contains("post:\n", view.Yaml);
-                    Assert.Contains("Post Run actions/has-post@v1", view.Yaml);
-                    Assert.DoesNotContain("Post Run actions/no-post@v1", view.Yaml);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnJobStepsInitialized_PostPredictionsInReverseOrder()
-        {
-            using (var hc = CreateTestContext())
-            {
-                // Both actions have post — predictions must render in
-                // reverse declaration order to mirror the runner's LIFO
-                // post-execution order.
-                hc.SetSingleton<IActionManager>(NewActionManagerWithPost("actions/a", "actions/b").Object);
-
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-
-                    var aMain = NewActionRunner(ActionRunStage.Main, "Run actions/a@v1", "actions/a", "v1", actionId: Guid.NewGuid()).Object;
-                    var bMain = NewActionRunner(ActionRunStage.Main, "Run actions/b@v1", "actions/b", "v1", actionId: Guid.NewGuid()).Object;
-
-                    await _debugger.OnJobStepsInitializedAsync(new[] { aMain, bMain }, Array.Empty<IStep>());
-
-                    string yaml = _debugger.ExecutionView.Yaml;
-                    int idxPostB = yaml.IndexOf("Post Run actions/b@v1", StringComparison.Ordinal);
-                    int idxPostA = yaml.IndexOf("Post Run actions/a@v1", StringComparison.Ordinal);
-                    Assert.True(idxPostB > 0 && idxPostA > 0, "both post placeholders expected");
-                    // Reverse declaration order: Post B appears BEFORE Post A.
-                    Assert.True(idxPostB < idxPostA, $"expected Post B before Post A (b={idxPostB} a={idxPostA})");
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnJobStepsInitialized_SkipsScriptSteps()
-        {
-            using (var hc = CreateTestContext())
-            {
-                // Even if the action manager would say HasPost, the predictor
-                // must skip script run-steps because their reference is not
-                // a RepositoryPathReference.
-                hc.SetSingleton<IActionManager>(NewActionManagerWithPost(/* nothing */).Object);
-
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-
-                    var script = NewScriptActionRunner(ActionRunStage.Main, "Run script", Guid.NewGuid()).Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { script }, Array.Empty<IStep>());
-
-                    var view = _debugger.ExecutionView;
-                    Assert.NotNull(view);
-                    Assert.DoesNotContain("post:\n", view.Yaml);
-                    Assert.DoesNotContain("Post ", view.Yaml);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnJobStepsInitialized_SkipsSelfActions()
-        {
-            using (var hc = CreateTestContext())
-            {
-                // Self-action: ActionRunner.cs:106 guards against creating a
-                // Post for self-repository references. The predictor mirrors
-                // that, regardless of what the manifest reports.
-                hc.SetSingleton<IActionManager>(NewActionManagerWithPost("anything").Object);
-
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-
-                    var selfRunner = NewSelfActionRunner(ActionRunStage.Main, "Run ./local-action", Guid.NewGuid()).Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { selfRunner }, Array.Empty<IStep>());
-
-                    Assert.DoesNotContain("post:\n", _debugger.ExecutionView.Yaml);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnPostStepRegistered_ClaimsExistingPlaceholder()
-        {
-            using (var hc = CreateTestContext())
-            {
-                hc.SetSingleton<IActionManager>(NewActionManagerWithPost("actions/has-post").Object);
-
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-
-                    var actionId = Guid.NewGuid();
-                    var mainRunner = NewActionRunner(ActionRunStage.Main, "Run actions/has-post@v1", "actions/has-post", "v1", actionId: actionId).Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { mainRunner }, Array.Empty<IStep>());
-
-                    var view = _debugger.ExecutionView;
-                    int before = view.EntryCount;
-                    Assert.Equal(2, before); // main + predicted post placeholder
-
-                    // The real Post IActionRunner shares the same Action.Id
-                    // as the Main runner (ActionRunner.cs:131).
-                    var postRunner = NewActionRunner(ActionRunStage.Post, "Post actions/has-post@v1", "actions/has-post", "v1", actionId: actionId).Object;
-                    _debugger.OnPostStepRegistered(postRunner);
-
-                    // No new entry: the placeholder was claimed.
-                    Assert.Equal(before, view.EntryCount);
-                    Assert.NotNull(view.TryGetLineForStep(postRunner));
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnPostStepRegistered_UnpredictedFallsBackToAppend()
-        {
-            using (var hc = CreateTestContext())
-            {
-                // Manager returns no HasPost — no predictions made.
-                hc.SetSingleton<IActionManager>(NewActionManagerWithPost(/* nothing */).Object);
-
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-
-                    var mainRunner = NewActionRunner(ActionRunStage.Main, "Run actions/a@v1", "actions/a", "v1", actionId: Guid.NewGuid()).Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { mainRunner }, Array.Empty<IStep>());
-
-                    var view = _debugger.ExecutionView;
-                    int before = view.EntryCount;
-                    Assert.Equal(1, before); // just main, no predicted post
-
-                    var unpredictedPost = NewActionRunner(ActionRunStage.Post, "Post Surprise", "actions/surprise", "v1", actionId: Guid.NewGuid()).Object;
-                    _debugger.OnPostStepRegistered(unpredictedPost);
-
-                    // Falls back to Append.
-                    Assert.Equal(before + 1, view.EntryCount);
-                    Assert.NotNull(view.TryGetLineForStep(unpredictedPost));
-                    Assert.Contains("Post Surprise", view.Yaml);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task OnPostStepRegistered_DuplicateClaim_NoDoubleEntry()
-        {
-            using (var hc = CreateTestContext())
-            {
-                hc.SetSingleton<IActionManager>(NewActionManagerWithPost("actions/has-post").Object);
-
-                var port = GetFreePort();
-                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
-                var jobContext = CreateJobContextWithTunnel(cts.Token, port);
-                await _debugger.StartAsync(jobContext.Object);
-                try
-                {
-                    await DriveToReadyAsync(_debugger, port);
-
-                    var actionId = Guid.NewGuid();
-                    var mainRunner = NewActionRunner(ActionRunStage.Main, "Run actions/has-post@v1", "actions/has-post", "v1", actionId: actionId).Object;
-                    await _debugger.OnJobStepsInitializedAsync(new[] { mainRunner }, Array.Empty<IStep>());
-                    Assert.Equal(2, _debugger.ExecutionView.EntryCount);
-
-                    // First registration claims the placeholder.
-                    var post1 = NewActionRunner(ActionRunStage.Post, "Post actions/has-post@v1", "actions/has-post", "v1", actionId: actionId).Object;
-                    _debugger.OnPostStepRegistered(post1);
-                    Assert.Equal(2, _debugger.ExecutionView.EntryCount);
-
-                    // Second registration with the same Action.Id but a
-                    // different IStep: TryClaim returns null (already
-                    // claimed). Falls through to Append. But the entry
-                    // it builds matches no existing step, so a new entry
-                    // would be added — UNLESS we constructed the second
-                    // post as a duplicate IStep registration of the same
-                    // step. Here we intentionally pass the same `post1`
-                    // step a second time — Append will reject the
-                    // already-registered step, the handler swallows it.
-                    _debugger.OnPostStepRegistered(post1);
-
-                    Assert.Equal(2, _debugger.ExecutionView.EntryCount);
-                }
-                finally
-                {
-                    await _debugger.StopAsync();
-                }
-            }
-        }
-    }
-}

src/Test/L0/Worker/JobExecutionViewRendererL0.cs

@@ -517,36 +517,6 @@ namespace GitHub.Runner.Common.Tests.Worker
             Assert.Contains("  - step: Complete job\n", result.Yaml);
         }
 
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public void Render_ReportsCompleteJobLineMatchingYaml()
-        {
-            // Empty entries — Cleanup still emitted.
-            var emptyResult = JobExecutionViewRenderer.Render("j", new List<JobExecutionViewEntry>());
-            AssertCompleteJobLineMatchesYaml(emptyResult);
-
-            // Non-empty entries across phases.
-            var populatedResult = JobExecutionViewRenderer.Render("build", WorkedExampleEntries());
-            AssertCompleteJobLineMatchesYaml(populatedResult);
-        }
-
-        private static void AssertCompleteJobLineMatchesYaml(RenderResult result)
-        {
-            var lines = result.Yaml.Split('\n');
-            int? actual = null;
-            for (int i = 0; i < lines.Length; i++)
-            {
-                if (lines[i] == "  - step: Complete job")
-                {
-                    actual = i + 1;
-                    break;
-                }
-            }
-            Assert.NotNull(actual);
-            Assert.Equal(actual.Value, result.CompleteJobLine);
-        }
-
         [Fact]
         [Trait("Level", "L0")]
         [Trait("Category", "Worker")]

src/Test/L0/Worker/JobExtensionL0.cs

@@ -141,7 +141,6 @@ namespace GitHub.Runner.Common.Tests.Worker
             hc.SetSingleton(_diagnosticLogManager.Object);
             hc.SetSingleton(_jobHookProvider.Object);
             hc.SetSingleton(_snapshotOperationProvider.Object);
-            hc.SetSingleton(new Mock<IDapDebugger>().Object);
             hc.EnqueueInstance<IPagingLogger>(_logger.Object); // JobExecutionContext
             hc.EnqueueInstance<IPagingLogger>(_logger.Object); // job start hook
             hc.EnqueueInstance<IPagingLogger>(_logger.Object); // Initial Job

src/Test/L0/Worker/JobRunnerL0.cs

@@ -1,6 +1,5 @@
 using GitHub.DistributedTask.WebApi;
 using GitHub.Runner.Worker;
-using GitHub.Runner.Worker.Dap;
 using Moq;
 using System;
 using System.Collections.Generic;
@@ -84,7 +83,6 @@ namespace GitHub.Runner.Common.Tests.Worker
             hc.SetSingleton(_extensions.Object);
             hc.SetSingleton(_temp.Object);
             hc.SetSingleton(_diagnosticLogManager.Object);
-            hc.SetSingleton(new Mock<IDapDebugger>().Object);
             hc.EnqueueInstance<IExecutionContext>(_jobEc);
             hc.EnqueueInstance<IPagingLogger>(_logger.Object);
             hc.EnqueueInstance<IJobExtension>(_jobExtension.Object);
@@ -177,29 +175,5 @@ namespace GitHub.Runner.Common.Tests.Worker
                 Assert.Equal(TaskResult.Succeeded, _jobEc.Result);
             }
         }
-
-        [Fact]
-        [Trait("Level", "L0")]
-        [Trait("Category", "Worker")]
-        public async Task DebuggerDisabled_DoesNotInvokeDapDebugger()
-        {
-            using (TestHostContext hc = CreateTestContext())
-            {
-                // Override the lenient IDapDebugger singleton from CreateTestContext
-                // with a strict mock. If the containment guard fails, the production
-                // code will call OnJobStepsInitializedAsync and the strict mock will throw.
-                var dapMock = new Mock<IDapDebugger>(MockBehavior.Strict);
-                hc.SetSingleton(dapMock.Object);
-
-                var message = GetMessage();
-                // EnableDebugger defaults to false on AgentJobRequestMessage.
-                Assert.False(message.EnableDebugger);
-
-                await _jobRunner.RunAsync(message, _tokenSource.Token);
-
-                Assert.Equal(TaskResult.Succeeded, _jobEc.Result);
-                dapMock.VerifyNoOtherCalls();
-            }
-        }
     }
 }