feat: add Svelte task prompt

src/lib/constants.ts

@@ -1,23 +0,0 @@
-export const base_runes = [
-	'$state',
-	'$effect',
-	'$derived',
-	'$inspect',
-	'$props',
-	'$bindable',
-	'$host',
-] as const;
-
-export const nested_runes = [
-	'$state.raw',
-	'$state.snapshot',
-	'$effect.pre',
-	'$effect.tracking',
-	'$effect.pending',
-	'$effect.root',
-	'$derived.by',
-	'$inspect.trace',
-	'$props.id',
-] as const;
-
-export const runes = [...base_runes, ...nested_runes] as const;

src/lib/mcp/autofixers/add-autofixers-issues.test.ts

@@ -1,25 +1,18 @@
 import { describe, expect, it } from 'vitest';
-import { add_autofixers_issues } from './add-autofixers-issues.js';
-import { base_runes } from '../../constants.js';
-
-const dollarless_runes = base_runes.map((r) => ({ rune: r.replace('$', '') }));
-
-function run_autofixers_on_code(code: string, desired_svelte_version = 5) {
-	const content = { issues: [], suggestions: [] };
-	add_autofixers_issues(content, code, desired_svelte_version);
-	return content;
-}
+import { add_autofixers_issues } from './add-autofixers-issues';
 
 describe('add_autofixers_issues', () => {
 	describe('assign_in_effect', () => {
-		it(`should add suggestions when assigning to a stateful variable inside an effect`, () => {
-			const content = run_autofixers_on_code(`
+		it('should add suggestions when assigning to a stateful variable inside an effect', () => {
+			const content = { issues: [], suggestions: [] };
+			const code = `
 			<script>
 				const count = $state(0);
 				$effect(() => {
 					count = 43;
 				});
-			</script>`);
+			</script>`;
+			add_autofixers_issues(content, code, 5);
 
 			expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
 			expect(content.suggestions).toContain(
@@ -27,8 +20,9 @@ describe('add_autofixers_issues', () => {
 			);
 		});
 
-		it(`should add a suggestion for each variable assigned within an effect`, () => {
-			const content = run_autofixers_on_code(`
+		it('should add a suggestion for each variable assigned within an effect', () => {
+			const content = { issues: [], suggestions: [] };
+			const code = `
 			<script>
 				const count = $state(0);
 				const count2 = $state(0);
@@ -36,7 +30,8 @@ describe('add_autofixers_issues', () => {
 					count = 43;
 					count2 = 44;
 				});
-			</script>`);
+			</script>`;
+			add_autofixers_issues(content, code, 5);
 
 			expect(content.suggestions.length).toBeGreaterThanOrEqual(2);
 			expect(content.suggestions).toContain(
@@ -46,14 +41,16 @@ describe('add_autofixers_issues', () => {
 				'The stateful variable "count2" is assigned inside an $effect which is generally consider a malpractice. Consider using $derived if possible.',
 			);
 		});
-		it(`should not add a suggestion for variables that are not assigned within an effect`, () => {
-			const content = run_autofixers_on_code(`
+		it('should not add a suggestion for variables that are not assigned within an effect', () => {
+			const content = { issues: [], suggestions: [] };
+			const code = `
 			<script>
 				const count = $state(0);
 			</script>
 			
 			<button onclick={() => count = 43}>Increment</button>
-			`);
+			`;
+			add_autofixers_issues(content, code, 5);
 
 			expect(content.suggestions).not.toContain(
 				'The stateful variable "count" is assigned inside an $effect which is generally consider a malpractice. Consider using $derived if possible.',
@@ -61,22 +58,25 @@ describe('add_autofixers_issues', () => {
 		});
 
 		it("should not add a suggestions for variables that are assigned within an effect but aren't stateful", () => {
-			const content = run_autofixers_on_code(`
+			const content = { issues: [], suggestions: [] };
+			const code = `
 			<script>
 				const count = 0;
 				
 				$effect(() => {
 					count = 43;
 				});
-			</script>`);
+			</script>`;
+			add_autofixers_issues(content, code, 5);
 
 			expect(content.suggestions).not.toContain(
 				'The stateful variable "count" is assigned inside an $effect which is generally consider a malpractice. Consider using $derived if possible.',
 			);
 		});
 
-		it(`should add a suggestion for variables that are assigned within an effect with an update`, () => {
-			const content = run_autofixers_on_code(`
+		it('should add a suggestion for variables that are assigned within an effect with an update', () => {
+			const content = { issues: [], suggestions: [] };
+			const code = `
 			<script>
 				let count = $state(0);
 				
@@ -84,15 +84,17 @@ describe('add_autofixers_issues', () => {
 					count++;
 				});
 			</script>
-			`);
+			`;
+			add_autofixers_issues(content, code, 5);
 
 			expect(content.suggestions).toContain(
 				'The stateful variable "count" is assigned inside an $effect which is generally consider a malpractice. Consider using $derived if possible.',
 			);
 		});
 
-		it(`should add a suggestion for variables that are mutated within an effect`, () => {
-			const content = run_autofixers_on_code(`
+		it('should add a suggestion for variables that are mutated within an effect', () => {
+			const content = { issues: [], suggestions: [] };
+			const code = `
 			<script>
 				let count = $state({ value: 0 });
 				
@@ -100,248 +102,12 @@ describe('add_autofixers_issues', () => {
 					count.value = 42;
 				});
 			</script>
-			`);
+			`;
+			add_autofixers_issues(content, code, 5);
 
 			expect(content.suggestions).toContain(
 				'The stateful variable "count" is assigned inside an $effect which is generally consider a malpractice. Consider using $derived if possible.',
 			);
 		});
 	});
-
-	describe.each([{ method: 'set' }, { method: 'update' }])(
-		'set_or_update_state ($method)',
-		({ method }) => {
-			it(`should add suggestions when using .${method}() on a stateful variable with a literal init`, () => {
-				const content = run_autofixers_on_code(`
-			<script>
-				const count = $state(0);
-				function update_count() {
-					count.${method}(43);
-				}
-			</script>`);
-
-				expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
-				expect(content.suggestions).toContain(
-					`You are trying to update the stateful variable "count" using "${method}". stateful variables should be updated with a normal assignment/mutation, do not use methods to update them.`,
-				);
-			});
-
-			it(`should add suggestions when using .${method}() on a stateful variable with an array init`, () => {
-				const content = run_autofixers_on_code(`
-			<script>
-				const count = $state([0]);
-				function update_count() {
-					count.${method}([1]);
-				}
-			</script>`);
-
-				expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
-				expect(content.suggestions).toContain(
-					`You are trying to update the stateful variable "count" using "${method}". stateful variables should be updated with a normal assignment/mutation, do not use methods to update them.`,
-				);
-			});
-
-			it(`should add suggestions when using .${method}() on a stateful variable with conditional if it's not sure if the method could actually be present on the variable ($state({}))`, () => {
-				const content = run_autofixers_on_code(`
-			<script>
-				const count = $state({ value: 0 });
-				function update_count() {
-					count.${method}({ value: 43 });
-				}
-			</script>`);
-
-				expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
-				expect(content.suggestions).toContain(
-					`You are trying to update the stateful variable "count" using "${method}". stateful variables should be updated with a normal assignment/mutation, do not use methods to update them. However I can't verify if "count" is a state variable of an object or a class with a "${method}" method on it. Please verify that before updating the code to use a normal assignment`,
-				);
-			});
-
-			it(`should add suggestions when using .${method}() on a stateful variable with conditional if it's not sure if the method could actually be present on the variable ($state(new Class()))`, () => {
-				const content = run_autofixers_on_code(`
-			<script>
-				const count = $state(new Class());
-				function update_count() {
-					count.${method}(new Class());
-				}
-			</script>`);
-
-				expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
-				expect(content.suggestions).toContain(
-					`You are trying to update the stateful variable "count" using "${method}". stateful variables should be updated with a normal assignment/mutation, do not use methods to update them. However I can't verify if "count" is a state variable of an object or a class with a "${method}" method on it. Please verify that before updating the code to use a normal assignment`,
-				);
-			});
-
-			it(`should add suggestions when using .${method}() on a stateful variable with conditional if it's not sure if the method could actually be present on the variable ($state(variable_name))`, () => {
-				const content = run_autofixers_on_code(`
-			<script>
-				const { init } = $props();
-				const count = $state(init);
-				function update_count() {
-					count.${method}(43);
-				}
-			</script>`);
-
-				expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
-				expect(content.suggestions).toContain(
-					`You are trying to update the stateful variable "count" using "${method}". stateful variables should be updated with a normal assignment/mutation, do not use methods to update them. However I can't verify if "count" is a state variable of an object or a class with a "${method}" method on it. Please verify that before updating the code to use a normal assignment`,
-				);
-			});
-
-			it(`should not add suggestions when using .${method} on a stateful variable if it's not a method call`, () => {
-				const content = run_autofixers_on_code(`
-			<script>
-				const count = $state({});
-				function update_count() {
-					console.log(count.${method});
-				}
-			</script>`);
-
-				expect(content.suggestions).not.toContain(
-					`You are trying to update the stateful variable "count" using "${method}". stateful variables should be updated with a normal assignment/mutation, do not use methods to update them. However I can't verify if "count" is a state variable of an object or a class with a "${method}" method on it. Please verify that before updating the code to use a normal assignment`,
-				);
-			});
-		},
-	);
-
-	describe('imported_runes', () => {
-		describe.each([{ source: 'svelte' }, { source: 'svelte/runes' }])(
-			'from "$source"',
-			({ source }) => {
-				describe.each(dollarless_runes)('single import ($rune)', ({ rune }) => {
-					it(`should add suggestions when importing '${rune}' from '${source}'`, () => {
-						const content = run_autofixers_on_code(`
-					<script>
-						import { ${rune} } from '${source}';
-					</script>`);
-
-						expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
-						expect(content.suggestions).toContain(
-							`You are importing "${rune}" from "${source}". This is not necessary, all runes are globally available. Please remove this import and use "$${rune}" directly.`,
-						);
-					});
-
-					it(`should add suggestions when importing "${rune}" as the default export from '${source}'`, () => {
-						const content = run_autofixers_on_code(`
-					<script>
-						import ${rune} from '${source}';
-					</script>`);
-
-						expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
-						expect(content.suggestions).toContain(
-							`You are importing "${rune}" from "${source}". This is not necessary, all runes are globally available. Please remove this import and use "$${rune}" directly.`,
-						);
-					});
-
-					it(`should add suggestions when importing '${rune}' as the namespace export from '${source}'`, () => {
-						const content = run_autofixers_on_code(`
-					<script>
-						import * as ${rune} from '${source}';
-					</script>`);
-
-						expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
-						expect(content.suggestions).toContain(
-							`You are importing "${rune}" from "${source}". This is not necessary, all runes are globally available. Please remove this import and use "$${rune}" directly.`,
-						);
-					});
-				});
-
-				it(`should add suggestions when importing multiple runes from '${source}'`, () => {
-					const content = run_autofixers_on_code(`
-					<script>
-						import { onMount, state, effect } from '${source}';
-					</script>`);
-
-					expect(content.suggestions.length).toBeGreaterThanOrEqual(2);
-					expect(content.suggestions).toContain(
-						`You are importing "state" from "${source}". This is not necessary, all runes are globally available. Please remove this import and use "$state" directly.`,
-					);
-					expect(content.suggestions).toContain(
-						`You are importing "effect" from "${source}". This is not necessary, all runes are globally available. Please remove this import and use "$effect" directly.`,
-					);
-				});
-
-				it(`should not add suggestions when importing other identifiers from '${source}'`, () => {
-					const content = run_autofixers_on_code(`
-					<script>
-						import { onMount } from '${source}';
-					</script>`);
-
-					expect(content.suggestions).not.toContain(
-						`You are importing "onMount" from "${source}". This is not necessary, all runes are globally available. Please remove this import and use "$onMount" directly.`,
-					);
-				});
-			},
-		);
-	});
-
-	describe('derived_with_function', () => {
-		it(`should add suggestions when using a function as the first argument to $derived`, () => {
-			const content = run_autofixers_on_code(`
-			<script>
-				const value = $derived(() => {
-					return 43;
-				});
-			</script>`);
-
-			expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
-			expect(content.suggestions).toContain(
-				'You are passing a function to $derived when declaring "value" but $derived expects an expression. You can use $derived.by instead.',
-			);
-		});
-
-		it(`should add suggestions when using a function as the first argument to $derived in classes`, () => {
-			const content = run_autofixers_on_code(`
-			<script>
-				class Double {
-					value = $derived(() => 43);
-				}
-			</script>`);
-
-			expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
-			expect(content.suggestions).toContain(
-				'You are passing a function to $derived when declaring "value" but $derived expects an expression. You can use $derived.by instead.',
-			);
-		});
-
-		it(`should add suggestions when using a function as the first argument to $derived in classes constructors`, () => {
-			const content = run_autofixers_on_code(`
-			<script>
-				class Double {
-					value;
-
-					constructor(){
-						this.value = $derived(function() { return 44; });
-					}
-				}
-			</script>`);
-
-			expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
-			expect(content.suggestions).toContain(
-				'You are passing a function to $derived when declaring "value" but $derived expects an expression. You can use $derived.by instead.',
-			);
-		});
-
-		it(`should add suggestions when using a function as the first argument to $derived without the declaring part if it's not an identifier`, () => {
-			const content = run_autofixers_on_code(`
-			<script>
-				const { destructured } = $derived(() => 43);
-			</script>`);
-
-			expect(content.suggestions.length).toBeGreaterThanOrEqual(1);
-			expect(content.suggestions).toContain(
-				'You are passing a function to $derived but $derived expects an expression. You can use $derived.by instead.',
-			);
-		});
-
-		it(`should add suggestions when using a function as the first argument to $derived.by`, () => {
-			const content = run_autofixers_on_code(`
-			<script>
-				const { destructured } = $derived.by(() => 43);
-			</script>`);
-
-			expect(content.suggestions).not.toContain(
-				'You are passing a function to $derived but $derived expects an expression. You can use $derived.by instead.',
-			);
-		});
-	});
 });

src/lib/mcp/autofixers/visitors/assign-in-effect.ts

@@ -1,6 +1,6 @@
 import type { AssignmentExpression, Identifier, Node, UpdateExpression } from 'estree';
 import type { Autofixer, AutofixerState } from '.';
-import { left_most_id } from '../ast/utils.js';
+import { left_most_id } from '../ast/utils';
 import type { SvelteNode } from 'svelte-eslint-parser/lib/ast';
 import type { Context } from 'zimmerframe';
 

src/lib/mcp/autofixers/visitors/derived-with-function.ts

@@ -1,41 +0,0 @@
-import type { Identifier, PrivateIdentifier } from 'estree';
-import type { Autofixer } from '.';
-
-export const derived_with_function: Autofixer = {
-	CallExpression(node, { state, path }) {
-		if (
-			node.callee.type === 'Identifier' &&
-			node.callee.name === '$derived' &&
-			state.parsed.is_rune(node, ['$derived']) &&
-			(node.arguments[0].type === 'ArrowFunctionExpression' ||
-				node.arguments[0].type === 'FunctionExpression')
-		) {
-			const parent = path[path.length - 1];
-			let variable_id: Identifier | PrivateIdentifier | undefined;
-			if (parent.type === 'VariableDeclarator' && parent.id.type === 'Identifier') {
-				// const something = $derived(...)
-				variable_id = parent.id;
-			} else if (parent.type === 'PropertyDefinition') {
-				// class X { something = $derived(...) }
-				variable_id =
-					parent.key.type === 'Identifier'
-						? parent.key
-						: parent.key.type === 'PrivateIdentifier'
-							? parent.key
-							: undefined;
-			} else if (parent.type === 'AssignmentExpression') {
-				// this.something = $derived(...)
-				variable_id =
-					parent.left.type === 'MemberExpression'
-						? parent.left.property.type === 'Identifier'
-							? parent.left.property
-							: undefined
-						: undefined;
-			}
-
-			state.output.suggestions.push(
-				`You are passing a function to $derived ${variable_id ? `when declaring "${variable_id.name}" ` : ''}but $derived expects an expression. You can use $derived.by instead.`,
-			);
-		}
-	},
-};

src/lib/mcp/autofixers/visitors/imported-runes.ts

@@ -1,28 +0,0 @@
-import { base_runes } from '../../../constants.js';
-import type { Autofixer } from '.';
-
-const dollarless_runes = base_runes.map((r) => r.replace('$', ''));
-
-export const imported_runes: Autofixer = {
-	ImportDeclaration(node, { state, next }) {
-		const source = (node.source.value || node.source.raw?.slice(1, -1))?.toString();
-		if (source && source.startsWith('svelte')) {
-			for (const specifier of node.specifiers) {
-				const id =
-					specifier.type === 'ImportDefaultSpecifier'
-						? specifier.local
-						: specifier.type === 'ImportNamespaceSpecifier'
-							? specifier.local
-							: specifier.type === 'ImportSpecifier'
-								? specifier.imported
-								: null;
-				if (id && id.type === 'Identifier' && dollarless_runes.includes(id.name)) {
-					state.output.suggestions.push(
-						`You are importing "${id.name}" from "${source}". This is not necessary, all runes are globally available. Please remove this import and use "$${id.name}" directly.`,
-					);
-				}
-			}
-		}
-		next();
-	},
-};

src/lib/mcp/autofixers/visitors/index.ts

@@ -12,6 +12,3 @@ export type AutofixerState = {
 export type Autofixer = Visitors<Node | AST.SvelteNode, AutofixerState>;
 
 export * from './assign-in-effect.js';
-export * from './set-or-update-state.js';
-export * from './imported-runes.js';
-export * from './derived-with-function.js';

src/lib/mcp/autofixers/visitors/set-or-update-state.ts

@@ -1,37 +0,0 @@
-import type { Autofixer } from '.';
-import { left_most_id } from '../ast/utils.js';
-
-const UPDATE_PROPERTIES = ['set', 'update'];
-
-export const set_or_update_state: Autofixer = {
-	MemberExpression(node, { state, next, path }) {
-		const parent = path[path.length - 1];
-		if (
-			parent.type === 'CallExpression' &&
-			parent.callee === node &&
-			node.property.type === 'Identifier' &&
-			UPDATE_PROPERTIES.includes(node.property.name)
-		) {
-			const id = left_most_id(node);
-			if (id) {
-				const reference = state.parsed.find_reference_by_id(id);
-				const definition = reference?.resolved?.defs[0];
-				if (definition && definition.type === 'Variable') {
-					const init = definition.node.init;
-					if (
-						init?.type === 'CallExpression' &&
-						state.parsed.is_rune(init, ['$state', '$state.raw'])
-					) {
-						let suggestion = `You are trying to update the stateful variable "${id.name}" using "${node.property.name}". stateful variables should be updated with a normal assignment/mutation, do not use methods to update them.`;
-						const argument = init.arguments[0];
-						if (!argument || (argument.type !== 'Literal' && argument.type !== 'ArrayExpression')) {
-							suggestion += ` However I can't verify if "${id.name}" is a state variable of an object or a class with a "${node.property.name}" method on it. Please verify that before updating the code to use a normal assignment`;
-						}
-						state.output.suggestions.push(suggestion);
-					}
-				}
-			}
-		}
-		next();
-	},
-};

src/lib/mcp/index.ts

@@ -89,6 +89,46 @@ server.tool(
 	},
 );
 
+server.prompt(
+	{
+		name: 'svelte-task-prompt',
+		title: 'Svelte Task Prompt',
+		description:
+			'Use this Prompt to ask for any svelte related task. It will automatically instruct the LLM on how to best use the autofixer and how to query for documentation pages.',
+		schema: v.object({
+			task: v.pipe(v.string(), v.description('The task to be performed')),
+		}),
+	},
+	async ({ task }) => {
+		// TODO: implement logic to fetch the available docs paths to return in the prompt
+		const available_docs: string[] = [];
+
+		return {
+			messages: [
+				{
+					role: 'user',
+					content: {
+						type: 'text',
+						text: `You are a Svelte expert tasked to build components and utilities for Svelte developers. If you need documentation for anything related to Svelte you can invoke the tool \`get_documentation\` with one of the following paths:
+<available-docs-paths>						
+${JSON.stringify(available_docs, null, 2)}
+</available-docs-paths>
+
+Every time you write a Svelte component or a Svelte module you MUST invoke the \`svelte-autofixer\` tool providing the code. The tool will return a list of issues or suggestions. If there are any issues or suggestions you MUST fix them and call the tool again with the updated code. You MUST keep doing this until the tool returns no issues or suggestions. Only then you can return the code to the user.
+
+This is the task you will work on:
+
+<task>
+${task}
+</task>
+`,
+					},
+				},
+			],
+		};
+	},
+);
+
 export const http_transport = new HttpTransport(server, {
 	cors: true,
 });

src/lib/parse/parse.ts

@@ -2,7 +2,6 @@ import ts_parser from '@typescript-eslint/parser';
 import type { CallExpression, Identifier } from 'estree';
 import type { Reference, Variable } from 'eslint-scope';
 import { parseForESLint as svelte_eslint_parse } from 'svelte-eslint-parser';
-import { runes } from '../constants.js';
 
 type Scope = {
 	variables?: Variable[];
@@ -19,6 +18,25 @@ function collect_scopes(scope: Scope, acc: Scope[] = []) {
 	return acc;
 }
 
+const runes = [
+	'$state',
+	'$state.raw',
+	'$state.snapshot',
+	'$effect',
+	'$effect.pre',
+	'$effect.tracking',
+	'$effect.pending',
+	'$effect.root',
+	'$derived',
+	'$derived.by',
+	'$inspect',
+	'$inspect.trace',
+	'$props',
+	'$props.id',
+	'$bindable',
+	'$host',
+] as const;
+
 export type ParseResult = ReturnType<typeof parse>;
 
 export function parse(code: string, file_path: string) {