Warn when Mutator in directive does not exist

packages/instrumenter/src/instrumenter.ts

@@ -37,7 +37,7 @@ export class Instrumenter {
     const parse = this._createParser(options);
     for await (const { name, mutate, content } of files) {
       const ast = await parse(content, name);
-      this._transform(ast, mutantCollector, { options, mutateDescription: toBabelLineNumber(mutate) });
+      this._transform(ast, mutantCollector, { options, mutateDescription: toBabelLineNumber(mutate), logger: this.logger });
       const mutatedContent = this._print(ast);
       outFiles.push({
         name,

packages/instrumenter/src/transformers/babel-transformer.ts

@@ -27,7 +27,7 @@ type PlacementMap = Map<types.Node, MutantsPlacement<types.Node>>;
 export const transformBabel: AstTransformer<ScriptFormat> = (
   { root, originFileName, rawContent, offset },
   mutantCollector,
-  { options, mutateDescription },
+  { options, mutateDescription, logger },
   mutators = allMutators,
   mutantPlacers = allMutantPlacers
 ) => {
@@ -39,7 +39,7 @@ export const transformBabel: AstTransformer<ScriptFormat> = (
   const placementMap: PlacementMap = new Map();
 
   // Create the bookkeeper responsible for the // Stryker ... directives
-  const directiveBookkeeper = new DirectiveBookkeeper();
+  const directiveBookkeeper = new DirectiveBookkeeper(logger, mutators, originFileName);
 
   // Now start the actual traversing of the AST
   //

packages/instrumenter/src/transformers/directive-bookkeeper.ts

@@ -1,6 +1,10 @@
 import type { types } from '@babel/core';
 import { notEmpty } from '@stryker-mutator/util';
 
+import { Logger } from '@stryker-mutator/api/logging';
+
+import { NodeMutator } from '../mutators/node-mutator.js';
+
 const WILDCARD = 'all';
 const DEFAULT_REASON = 'Ignored using a comment';
 
@@ -47,18 +51,26 @@ export class DirectiveBookkeeper {
   private readonly strykerCommentDirectiveRegex = /^\s?Stryker (disable|restore)(?: (next-line))? ([a-zA-Z, ]+)(?::(.+)?)?/;
 
   private currentIgnoreRule = rootRule;
+  private readonly allMutatorNames: string[];
+
+  constructor(private readonly logger: Logger, private readonly allMutators: NodeMutator[], private readonly originFileName: string) {
+    this.allMutatorNames = this.allMutators.map((x) => x.name.toLowerCase());
+  }
 
   public processStrykerDirectives({ loc, leadingComments }: types.Node): void {
     leadingComments
-      ?.map(
-        (comment) =>
-          this.strykerCommentDirectiveRegex.exec(comment.value) as
-            | [fullMatch: string, directiveType: string, scope: string | undefined, mutators: string, reason: string | undefined]
-            | null
-      )
-      .filter(notEmpty)
-      .forEach(([, directiveType, scope, mutators, optionalReason]) => {
-        const mutatorNames = mutators.split(',').map((mutator) => mutator.trim().toLowerCase());
+      ?.map((comment) => ({
+        comment,
+        matchResult: this.strykerCommentDirectiveRegex.exec(comment.value) as
+          | [fullMatch: string, directiveType: string, scope: string | undefined, mutators: string, reason: string | undefined]
+          | null,
+      }))
+      .filter(({ matchResult }) => notEmpty(matchResult))
+      .forEach(({ comment, matchResult }) => {
+        const [, directiveType, scope, mutators, optionalReason] = matchResult!;
+        let mutatorNames = mutators.split(',').map((mutator) => mutator.trim());
+        this.warnAboutUnusedDirective(mutatorNames, directiveType, scope, comment);
+        mutatorNames = mutatorNames.map((mutator) => mutator.toLowerCase());
         const reason = (optionalReason ?? DEFAULT_REASON).trim();
         switch (directiveType) {
           case 'disable':
@@ -89,4 +101,20 @@ export class DirectiveBookkeeper {
     mutatorName = mutatorName.toLowerCase();
     return this.currentIgnoreRule.findIgnoreReason(mutatorName, line);
   }
+
+  private warnAboutUnusedDirective(mutators: string[], directiveType: string, scope: string | undefined, comment: types.Comment) {
+    for (const mutator of mutators) {
+      if (mutator === WILDCARD) continue;
+      if (!this.allMutatorNames.includes(mutator.toLowerCase())) {
+        this.logger.warn(
+          // Scope can be global and therefore undefined
+          `Unused 'Stryker ${
+            scope ? directiveType + ' ' + scope : directiveType
+          }' directive. Mutator with name '${mutator}' not found. Directive found at: ${this.originFileName}:${comment.loc!.start.line}:${
+            comment.loc!.start.column
+          }.`
+        );
+      }
+    }
+  }
 }

packages/instrumenter/src/transformers/transformer.ts

@@ -1,6 +1,8 @@
 import { MutateDescription } from '@stryker-mutator/api/core';
 import { I } from '@stryker-mutator/util';
 
+import { Logger } from '@stryker-mutator/api/src/logging/logger';
+
 import { Ast, AstByFormat, AstFormat } from '../syntax/index.js';
 
 import { TransformerOptions } from './transformer-options.js';
@@ -18,7 +20,7 @@ import { MutantCollector } from './mutant-collector.js';
 export function transform(
   ast: Ast,
   mutantCollector: I<MutantCollector>,
-  transformerContext: Pick<TransformerContext, 'mutateDescription' | 'options'>
+  transformerContext: Pick<TransformerContext, 'logger' | 'mutateDescription' | 'options'>
 ): void {
   const context: TransformerContext = {
     ...transformerContext,
@@ -42,4 +44,5 @@ export interface TransformerContext {
   transform: AstTransformer<AstFormat>;
   options: TransformerOptions;
   mutateDescription: MutateDescription;
+  logger: Logger;
 }

packages/instrumenter/test/helpers/stubs.ts

@@ -1,5 +1,7 @@
 import sinon from 'sinon';
 
+import { testInjector } from '@stryker-mutator/test-helpers';
+
 import { ParserContext } from '../../src/parsers/parser-context.js';
 import { PrinterContext } from '../../src/printers/index.js';
 import { TransformerContext } from '../../src/transformers/index.js';
@@ -23,5 +25,6 @@ export function transformerContextStub(): sinon.SinonStubbedInstance<Transformer
     transform: sinon.stub(),
     mutateDescription: true,
     options: createTransformerOptions(),
+    logger: testInjector.logger,
   };
 }

packages/instrumenter/test/integration/transformers.it.spec.ts

@@ -1,4 +1,5 @@
 import { expect } from 'chai';
+import { testInjector } from '@stryker-mutator/test-helpers';
 
 import { createHtmlAst, createJSAst, createTransformerOptions, createTSAst } from '../helpers/factories.js';
 import { transform } from '../../src/transformers/index.js';
@@ -9,21 +10,21 @@ describe('transformers integration', () => {
     const htmlAst = createHtmlAst();
     htmlAst.root.scripts.push(createJSAst({ rawContent: 'const foo = 40 + 2' }));
     const mutantCollector = new MutantCollector();
-    transform(htmlAst, mutantCollector, { options: createTransformerOptions(), mutateDescription: true });
+    transform(htmlAst, mutantCollector, { options: createTransformerOptions(), mutateDescription: true, logger: testInjector.logger });
     expect(mutantCollector.mutants).lengthOf(1);
     expect(htmlAst).matchSnapshot();
   });
   it('should transform a js file', () => {
     const jsAst = createJSAst({ rawContent: 'const foo = 40 + 2' });
     const mutantCollector = new MutantCollector();
-    transform(jsAst, mutantCollector, { options: createTransformerOptions(), mutateDescription: true });
+    transform(jsAst, mutantCollector, { options: createTransformerOptions(), mutateDescription: true, logger: testInjector.logger });
     expect(mutantCollector.mutants).lengthOf(1);
     expect(jsAst).matchSnapshot();
   });
   it('should transform a ts file', () => {
     const tsAst = createTSAst({ rawContent: 'const foo: number = 40 + 2' });
     const mutantCollector = new MutantCollector();
-    transform(tsAst, mutantCollector, { options: createTransformerOptions(), mutateDescription: true });
+    transform(tsAst, mutantCollector, { options: createTransformerOptions(), mutateDescription: true, logger: testInjector.logger });
     expect(mutantCollector.mutants).lengthOf(1);
     expect(tsAst).matchSnapshot();
   });

packages/instrumenter/test/unit/instrumenter.spec.ts

@@ -66,7 +66,11 @@ describe(Instrumenter.name, () => {
     const expected: transformers.TransformerOptions = createInstrumenterOptions({
       excludedMutations: [],
     });
-    expect(actual).deep.eq({ options: expected, mutateDescription: [{ start: { line: 1, column: 0 }, end: { line: 7, column: 42 } }] });
+    expect(actual).deep.eq({
+      options: expected,
+      mutateDescription: [{ start: { line: 1, column: 0 }, end: { line: 7, column: 42 } }],
+      logger: testInjector.logger,
+    });
   });
 
   it('should log about instrumenting', async () => {

packages/instrumenter/test/unit/transformers/babel-transformer.spec.ts

@@ -443,6 +443,68 @@ describe('babel-transformer', () => {
         expect(notIgnoredMutants()).lengthOf(1);
       });
 
+      it('should warn when a mutator name without scope does not match any of the enabled mutators.', () => {
+        const ast = createTSAst({
+          rawContent: `// Stryker disable RandomName: This Mutator does not exist
+              function test(a, b) {
+                return a - b >= 0 ? 1 : -1;
+              }
+            `,
+        });
+        act(ast);
+
+        expect(context.logger.warn).calledWithMatch(
+          sinon.match("Unused 'Stryker disable' directive. Mutator with name 'RandomName' not found. Directive found at: example.ts:1")
+        );
+      });
+
+      it('should warn when a mutator name with scope does not match any of the enabled mutators.', () => {
+        const ast = createTSAst({
+          rawContent: `// Stryker disable next-line RandomName: This Mutator does not exist
+              function test(a, b) {
+                return a - b >= 0 ? 1 : -1;
+              }
+            `,
+        });
+        act(ast);
+
+        expect(context.logger.warn).calledWithMatch(
+          sinon.match("Unused 'Stryker disable next-line' directive. Mutator with name 'RandomName' not found. Directive found at: example.ts:1")
+        );
+      });
+
+      it('should warn when a mutator name does not match any of the enabled mutators.', () => {
+        const ast = createTSAst({
+          rawContent: `// Stryker disable Foo
+              // Stryker disable RandomName: This Mutator does not exist
+              // Stryker disable Plus
+              function test(a, b) {
+                return a - b >= 0 ? 1 : -1;
+              }
+            `,
+        });
+        act(ast);
+
+        expect(context.logger.warn).calledWithMatch(
+          sinon.match("Unused 'Stryker disable' directive. Mutator with name 'RandomName' not found. Directive found at: example.ts:2")
+        );
+      });
+
+      it('should not warn when a disabled Mutator exists.', () => {
+        const ast = createTSAst({
+          rawContent: `
+              // Stryker disable Foo
+              // Stryker disable all
+              function test(a, b) {
+                return a - b >= 0 ? 1 : -1;
+              }
+            `,
+        });
+        act(ast);
+
+        expect(context.logger.warn).not.called;
+      });
+
       it('should allow to restore for next-line using a specific "Stryker restore next-line mutator" comment', () => {
         const ast = createTSAst({
           rawContent: `