@vitest/mocker 4.1.11: redirect.findMockRedirect

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify @vitest/mocker/redirect.findMockRedirect in pkg:npm/%40vitest/mocker@4.1.11
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40vitest/mocker@4.1.11
Demonstrate these symbols/APIs:
  - @vitest/mocker/redirect.findMockRedirect

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:9605a29ef29c740615a0ce3e7c59d7bb5b58391cf9e23f984ec18888957600c2","contract":["assert findMockRedirect is exported as a function","assert findMockRedirect resolves adjacent __mocks__/\u003cfilename\u003e for existing local source files","assert findMockRedirect resolves external package mocks in \u003croot\u003e/__mocks__/\u003cpackage\u003e.\u003cext\u003e","assert findMockRedirect resolves package mocks nested in directory index files","assert findMockRedirect resolves scoped package mocks under \u003croot\u003e/__mocks__/@scope/\u003cpackage\u003e.\u003cext\u003e","assert findMockRedirect resolves Node.js built-in modules under \u003croot\u003e/__mocks__/\u003cmodule\u003e.\u003cext\u003e","assert findMockRedirect returns null when no matching mock file exists in __mocks__"],"goal":"verify @vitest/mocker/redirect.findMockRedirect in pkg:npm/%40vitest/mocker@4.1.11","kind":"HOW","packages":["pkg:npm/%40vitest/mocker@4.1.11"],"schemaVersion":1,"symbols":["@vitest/mocker/redirect.findMockRedirect"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/%40vitest/mocker@4.1.11"],"schemaVersion":1,"subject":"pkg:npm/%40vitest/mocker@4.1.11","symbols":["@vitest/mocker/redirect.findMockRedirect"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-vitest-mocker",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-vitest-mocker",
      "version": "1.0.0",
      "license": "MIT-0",
      "dependencies": {
        "@vitest/mocker": "4.1.11"
      }
    },
    "node_modules/@jridgewell/sourcemap-codec": {
      "version": "1.6.0",
      "resolved": "https://registry.npmjs.org/@jridgewell/sourcemap-codec/-/sourcemap-codec-1.6.0.tgz",
      "integrity": "sha512-T7jf+5zgsZHwNJ4lvQ7/aezbyk0nNX+zJVWpmHA7VYsEx7a7qr5Rg5IbtJFqkgze5Y2sruq1RUY8Q837Od7iFw==",
      "license": "MIT"
    },
    "node_modules/@types/estree": {
      "version": "1.0.9",
      "resolved": "https://registry.npmjs.org/@types/estree/-/estree-1.0.9.tgz",
      "integrity": "sha512-GhdPgy1el4/ImP05X05Uw4cw2/M93BCUmnEvWZNStlCzEKME4Fkk+YpoA5OiHNQmoS7Cafb8Xa3Pya8m1Qrzeg==",
      "license": "MIT"
    },
    "node_modules/@vitest/mocker": {
      "version": "4.1.11",
      "resolved": "https://registry.npmjs.org/@vitest/mocker/-/mocker-4.1.11.tgz",
      "integrity": "sha512-2XJVD55d1o5AZous5CCGKS74g/riOj9odEt2bQpCVZeblHyHdnMeFl4jl0XjU21stf4mbjUkew2eXQZt65g5CQ==",
      "license": "MIT",
      "dependencies": {
        "@vitest/spy": "4.1.11",
        "estree-walker": "^3.0.3",
        "magic-string": "^0.30.21"
      },
      "funding": {
        "url": "https://opencollective.com/vitest"
      },
      "peerDependencies": {
        "msw": "^2.4.9",
        "vite": "^6.0.0 || ^7.0.0 || ^8.0.0"
      },
      "peerDependenciesMeta": {
        "msw": {
          "optional": true
        },
        "vite": {
          "optional": true
        }
      }
    },
    "node_modules/@vitest/spy": {
      "version": "4.1.11",
      "resolved": "https://registry.npmjs.org/@vitest/spy/-/spy-4.1.11.tgz",
      "integrity": "sha512-apNa/prQy2qCeywhnixOHPRCgGNhvg7T4Dapfl1GahLp/R+uhBm5cPyFoNVyqsNd2h1nJxL6BqqdIjiABL60YA==",
      "license": "MIT",
      "funding": {
        "url": "https://opencollective.com/vitest"
      }
    },
    "node_modules/estree-walker": {
      "version": "3.0.3",
      "resolved": "https://registry.npmjs.org/estree-walker/-/estree-walker-3.0.3.tgz",
      "integrity": "sha512-7RUKfXgSMMkzt6ZuXmqapOurLGPPfgj6l9uRZ7lRGolvk0y2yocc35LdcxKC5PQZdn2DMqioAQ2NoWcrTKmm6g==",
      "license": "MIT",
      "dependencies": {
        "@types/estree": "^1.0.0"
      }
    },
    "node_modules/magic-string": {
      "version": "0.30.21",
      "resolved": "https://registry.npmjs.org/magic-string/-/magic-string-0.30.21.tgz",
      "integrity": "sha512-vd2F4YUyEXKGcLHoq+TEyCjxueSeHnFxyyjNp80yg0XV4vUhnDer/lvvlqM/arB5bXQN5K2/3oinyCRyx8T2CQ==",
      "license": "MIT",
      "dependencies": {
        "@jridgewell/sourcemap-codec": "^1.5.5"
      }
    }
  }
}

{
  "name": "sample-vitest-mocker",
  "version": "1.0.0",
  "type": "module",
  "license": "MIT-0",
  "dependencies": {
    "@vitest/mocker": "4.1.11"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify @vitest/mocker/redirect.findMockRedirect in pkg:npm/%40vitest/mocker@4.1.11",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40vitest/mocker@4.1.11"
  ],
  "symbols": [
    "@vitest/mocker/redirect.findMockRedirect"
  ]
}

import assert from 'node:assert/strict';
import fs from 'node:fs';
import os from 'node:os';
import path from 'node:path';
import { findMockRedirect } from '@vitest/mocker/redirect';

// 1. Verify findMockRedirect is a function
assert.equal(typeof findMockRedirect, 'function');

const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'vitest-mocker-test-'));

try {
  const srcDir = path.join(tmpDir, 'src');
  const srcMocksDir = path.join(srcDir, '__mocks__');
  const rootMocksDir = path.join(tmpDir, '__mocks__');
  const scopedMocksDir = path.join(rootMocksDir, '@scoped');
  const complexLibDir = path.join(rootMocksDir, 'complex-lib');

  fs.mkdirSync(srcMocksDir, { recursive: true });
  fs.mkdirSync(scopedMocksDir, { recursive: true });
  fs.mkdirSync(complexLibDir, { recursive: true });

  const serviceFile = path.join(srcDir, 'service.js');
  const serviceMock = path.join(srcMocksDir, 'service.js');
  const helperFile = path.join(srcDir, 'helper.js');
  const axiosMock = path.join(rootMocksDir, 'axios.js');
  const fsMock = path.join(rootMocksDir, 'fs.js');
  const scopedMock = path.join(scopedMocksDir, 'pkg.js');
  const complexLibIndex = path.join(complexLibDir, 'index.js');

  fs.writeFileSync(serviceFile, 'export const run = () => "real";');
  fs.writeFileSync(serviceMock, 'export const run = () => "mocked";');
  fs.writeFileSync(helperFile, 'export const help = () => true;');
  fs.writeFileSync(axiosMock, 'export default { get: () => Promise.resolve({}) };');
  fs.writeFileSync(fsMock, 'export const readFileSync = () => "mock-fs";');
  fs.writeFileSync(scopedMock, 'export const value = 100;');
  fs.writeFileSync(complexLibIndex, 'export default {};');

  // 1. Resolves adjacent __mocks__/<filename> for existing local source files
  const resLocal = findMockRedirect(tmpDir, serviceFile, null);
  assert.equal(resLocal, serviceMock);

  // 2. Returns null when local file has no corresponding mock in __mocks__
  const resHelper = findMockRedirect(tmpDir, helperFile, null);
  assert.equal(resHelper, null);

  // 3. Resolves external package mocks in <root>/__mocks__/<package>.<ext>
  const resAxios = findMockRedirect(tmpDir, 'axios', null);
  assert.equal(resAxios, axiosMock);

  // 4. Resolves external package mocks when external argument is explicitly provided
  const resExternal = findMockRedirect(tmpDir, '/virtual/path/to/axios', 'axios');
  assert.equal(resExternal, axiosMock);

  // 5. Resolves scoped package mocks under <root>/__mocks__/@scope/<package>.<ext>
  const resScoped = findMockRedirect(tmpDir, '@scoped/pkg', null);
  assert.equal(resScoped, scopedMock);

  // 6. Resolves package mocks nested in directory index files
  const resNested = findMockRedirect(tmpDir, 'complex-lib', null);
  assert.equal(resNested, complexLibIndex);

  // 7. Resolves Node.js built-in modules under <root>/__mocks__/<module>.<ext>
  const resFs = findMockRedirect(tmpDir, 'fs', null);
  assert.equal(resFs, fsMock);

  // 8. Returns null when no corresponding mock file exists for external package
  const resNone = findMockRedirect(tmpDir, 'unmocked-package', null);
  assert.equal(resNone, null);
} finally {
  fs.rmSync(tmpDir, { recursive: true, force: true });
}