VITEST_FILES_NOT_FOUND error when running Stryker with Angular 18 and Vitest

[cquilezg]

Summary

I've added Vitest to my project, which uses Angular 18 and TypeScript. The tests run successfully with Vitest. However, when I try to run Stryker (using the Vitest runner extension), I encounter the following error:
15:45:22 (15888) ERROR DryRunExecutor One or more tests resulted in an error: Test runner crashed. Tried twice to restart it without any luck. Last time the error message was: Error: Error: VITEST_FILES_NOT_FOUND (undefined) Error: No test files found at Vitest.start (file:///C:/projects/github/angular18-vitest-stryker/node_modules/vitest/dist/chunks/cli-api.btGgw3PC.js:10518:15) at async VitestTestRunner.run (file:///C:/projects/github/angular18-vitest-stryker/node_modules/@stryker-mutator/vitest-runner/dist/src/vitest-test-runner.js:94:13) at async VitestTestRunner.dryRun (file:///C:/projects/github/angular18-vitest-stryker/node_modules/@stryker-mutator/vitest-runner/dist/src/vitest-test-runner.js:58:28) at async ChildProcessTestRunnerWorker.dryRun (file:///C:/projects/github/angular18-vitest-stryker/node_modules/@stryker-mutator/core/dist/src/test-runner/child-process-test-runner-worker.js:25:30)

Here the complete stryker.log for the command npx stryker run --fileLogLevel trace.

What I've Tried

• Tested in my real project with Angular 17 and with a new project also with Angular 17 -> same error.
• Confirmed that tests run correctly using vitest.
• Reviewed the Stryker documentation to ensure the configuration is accurate: https://stryker-mutator.io/docs/stryker-js/guides/angular/ and https://stryker-mutator.io/docs/stryker-js/vitest-runner/ .
• Debugged Stryker in VS Code adding this configuration to .vscode/launch.json:
  { "type": "node", "request": "launch", "name": "Debug Stryker", "skipFiles": ["<node_internals>/**"], "program": "${workspaceFolder}/node_modules/@stryker-mutator/core/bin/stryker", "args": ["run"], "console": "integratedTerminal", "outputCapture": "std" }

What I've seen when debugging is that in @stryker-mutator/core/dist/src/test-runner/child-process-test-runner-worker.js is invoking the corresponding testing runner with dryRun(options),

but vitest-test-runner.js is not accepting arguments.

Idk if this could be related with the problem.

Any Ideas for a Solution?
I would greatly appreciate any guidance or suggestions on how to resolve this issue.

I've uploaded the project here: angular18-vitest-stryker

Steps to Reproduce

• Create a new Angular 18 project with TypeScript.
• Set up Vitest as the testing framework.
• Ensure tests run correctly by executing vitest.
• Add Stryker and configure it to use the Vitest runner.
• Run Stryker with the following command:
  npx stryker run

Relevant Configuration

Angular: 18.2.0
TypeScript: 5.5.2
Vitest: 2.1.3
Stryker: 8.6.0

Stryker config

{
  "$schema": "./node_modules/@stryker-mutator/core/schema/stryker-schema.json",
  "packageManager": "npm",
  "reporters": ["html", "clear-text", "progress"],
  "testRunner": "vitest",
  "vitest": {
    "configFile": "vite.config.ts",
    "dir": "src"
  },
  "tsconfigFile": "tsconfig.json",
  "mutate": [
    "src/**/*.ts",
    "!src/**/*.spec.ts",
    "!src/main.ts",
    "!src/test-setup.ts",
    "!src/app/app.config.ts",
    "!src/environments/*.ts"
   ],
  "timeoutMS": 30000,
  "thresholds": {
    "high": 100,
    "low": 85,
    "break": 80
  },
  "incremental": true
 }

Test runner config

vite.config.ts

/// <reference types="vitest" />
import { defineConfig } from 'vite';

import angular from '@analogjs/vite-plugin-angular';

export default defineConfig(({ mode }) => ({
  plugins: [angular()],
  test: {
    globals: true,
    setupFiles: ['src/test-setup.ts'],
    environment: 'jsdom',
    include: ['src/**/*.{test,spec}.{js,mjs,cjs,ts,mts,cts,jsx,tsx}'],
    reporters: ['default'],
  },
  define: {
    'import.meta.vitest': mode !== 'production',
  },
}));

Stryker environment
Stryker dependencies:

+-- @stryker-mutator/[email protected]
+-- @stryker-mutator/[email protected]
+-- @stryker-mutator/[email protected]

Test runner dependencies:

+-- [email protected]
+-- @analogjs/[email protected]
+-- @analogjs/[email protected]
+-- @vitest/[email protected]

Test runner environment

# Test command
npx stryker run

src/test-setup.ts

import '@analogjs/vitest-angular/setup-snapshots';

import {
  BrowserDynamicTestingModule,
  platformBrowserDynamicTesting,
} from '@angular/platform-browser-dynamic/testing';
import { getTestBed } from '@angular/core/testing';

getTestBed().initTestEnvironment(
  BrowserDynamicTestingModule,
  platformBrowserDynamicTesting()
);

Your Environment

software	version(s)
node	22.11.0
npm	10.9.0
Operating System	Windows 10

Thank you in advance!