CodeSampleX

Ejemplo

jest-mock 29.7.0: fn

Muestra verificada para npm jest-mock 29.7.0: fn. El contrato se ejecutó en node 22 · linux debian/x64 · docker y pasó: fn creates a mock function that…

sha256:c3118cb3f4faa866d15da3d2999b2e580e5c5b4bdc9b892fd57fe4b4cd66ce39

Esta red ofrece una sola cosa: una muestra que compila. La ejecutó en un sandbox y guardó el recibo firmado. No califica ni garantiza nada: si el mismo código compila donde estás no es algo que haya medido. Cuántas claves de firma distintas presentaron un recibo de contrato aprobado. Una es solo el autor; más de una significa que alguien más también lo compiló. Una clave se genera sola y no tiene identidad registrada detrás, así que cuenta claves, no personas. MIT-0

Evidencia de ejecución

El entorno declarado y las ejecuciones firmadas se muestran por separado, para que veas exactamente qué ejecutó esta muestra y dónde.

Base de evidencia
Contrato firmado aprobado
Recibos de verificación
1
Claves de firma que lo compilaron
1
Entorno declarado node 22.23 linux 24 · ubuntu · glibc 2.39 x64 node 22.23 javascript npm 10

Entornos de las ejecuciones de verificación

Entorno Contrato Etapas Ejecución
node 22 · linux debian/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1node:22@sha256:8a34c4ab3ea2…		 2026-09-06

Caso

HOW
Objetivo
verify jest-mock.fn in pkg:npm/jest-mock@29.7.0
Paquetes
Símbolos
  • jest-mock.fn
Entorno
node 22.23.2
Creado
2026-09-06T07:53:28Z

Contrato

  1. fn creates a mock function that defaults to returning undefined and tracks call count and arguments
  2. fn records mock.calls, mock.results with return type, and mock.contexts for each invocation
  3. mockReturnValue and mockReturnValueOnce configure synchronous return values with once taking precedence
  4. mockResolvedValue and mockResolvedValueOnce return promises resolving to the configured values
  5. mockRejectedValue and mockRejectedValueOnce return promises rejecting with the configured errors
  6. mockImplementation and mockImplementationOnce override mock execution behavior sequentially
  7. mockReturnThis binds the returned value to the execution this context
  8. mockClear clears recorded calls and results while preserving current mock implementation
  9. mockReset clears recorded calls and resets implementation to return undefined
  10. withImplementation temporarily overrides mock implementation for the duration of a callback

Archivos

  • PROMPT.md
  • csx.json
  • index.js
  • package-lock.json
  • package.json
  • spec.json
  • test/contract.js

Descargar el artefacto de código fuente (tar.gz)

Código fuente

PROMPT.md
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 jest-mock.fn in pkg:npm/jest-mock@29.7.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/jest-mock@29.7.0
Demonstrate these symbols/APIs:
  - jest-mock.fn

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.
csx.json
{"case":{"caseId":"case:sha256:3e202a7070bf30aa087035d08a25b597461e31832c7801d94ca31210e7643435","contract":["fn creates a mock function that defaults to returning undefined and tracks call count and arguments","fn records mock.calls, mock.results with return type, and mock.contexts for each invocation","mockReturnValue and mockReturnValueOnce configure synchronous return values with once taking precedence","mockResolvedValue and mockResolvedValueOnce return promises resolving to the configured values","mockRejectedValue and mockRejectedValueOnce return promises rejecting with the configured errors","mockImplementation and mockImplementationOnce override mock execution behavior sequentially","mockReturnThis binds the returned value to the execution this context","mockClear clears recorded calls and results while preserving current mock implementation","mockReset clears recorded calls and resets implementation to return undefined","withImplementation temporarily overrides mock implementation for the duration of a callback"],"goal":"verify jest-mock.fn in pkg:npm/jest-mock@29.7.0","kind":"HOW","packages":["pkg:npm/jest-mock@29.7.0"],"schemaVersion":1,"symbols":["jest-mock.fn"]},"contractCommand":["node","test/contract.js"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"cjs","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/jest-mock@29.7.0"],"schemaVersion":1,"subject":"pkg:npm/jest-mock@29.7.0","symbols":["jest-mock.fn"],"verifierAdapter":"node-typescript@1"}
index.js
'use strict';

const jestMock = require('jest-mock');
const { fn } = jestMock;

/**
 * Creates a mock function with an optional implementation.
 * @param {Function} [implementation]
 * @returns {Function}
 */
function createMockFunction(implementation) {
  return fn(implementation);
}

/**
 * Creates an async mock function that resolves to the specified value.
 * @param {*} resolvedValue
 * @returns {Function}
 */
function createAsyncMock(resolvedValue) {
  const mock = fn();
  mock.mockResolvedValue(resolvedValue);
  return mock;
}

/**
 * Creates an async mock function that rejects with the specified reason.
 * @param {*} rejectionReason
 * @returns {Function}
 */
function createRejectingMock(rejectionReason) {
  const mock = fn();
  mock.mockRejectedValue(rejectionReason);
  return mock;
}

/**
 * Creates a mock function configured to return a sequence of values once,
 * then fall back to a default value.
 * @param {Array<*>} sequence
 * @param {*} [defaultValue]
 * @returns {Function}
 */
function createSequenceMock(sequence, defaultValue) {
  const mock = fn();
  if (defaultValue !== undefined) {
    mock.mockReturnValue(defaultValue);
  }
  for (const val of sequence) {
    mock.mockReturnValueOnce(val);
  }
  return mock;
}

/**
 * Creates a mock function that returns its `this` execution context.
 * @returns {Function}
 */
function createChainableMock() {
  const mock = fn();
  mock.mockReturnThis();
  return mock;
}

/**
 * Extracts metadata and call history from a mock function.
 * @param {Function} mockFn
 * @returns {object}
 */
function inspectMock(mockFn) {
  return {
    name: mockFn.getMockName(),
    callCount: mockFn.mock.calls.length,
    calls: [...mockFn.mock.calls],
    results: [...mockFn.mock.results],
    lastCall: mockFn.mock.lastCall
  };
}

module.exports = {
  fn,
  createMockFunction,
  createAsyncMock,
  createRejectingMock,
  createSequenceMock,
  createChainableMock,
  inspectMock
};
package-lock.json
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package.json
{
  "name": "sample-jest-mock-fn-verify",
  "version": "1.0.0",
  "private": true,
  "description": "verify jest-mock.fn in pkg:npm/jest-mock@29.7.0",
  "main": "index.js",
  "scripts": {
    "test": "node test/contract.js"
  },
  "dependencies": {
    "jest-mock": "29.7.0"
  },
  "license": "MIT-0"
}
spec.json
{
  "schemaVersion": 1,
  "goal": "verify jest-mock.fn in pkg:npm/jest-mock@29.7.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/jest-mock@29.7.0"
  ],
  "symbols": [
    "jest-mock.fn"
  ]
}
test/contract.js
'use strict';

const assert = require('assert');
const {
  fn,
  createMockFunction,
  createAsyncMock,
  createRejectingMock,
  createSequenceMock,
  createChainableMock,
  inspectMock
} = require('../index.js');

function testDefaultMockBehavior() {
  const mock = fn();
  assert.strictEqual(mock.getMockName(), 'jest.fn()');

  const result = mock('firstArg', 42);
  assert.strictEqual(result, undefined, 'default mock must return undefined');
  assert.strictEqual(mock.mock.calls.length, 1, 'call count must be 1');
  assert.deepStrictEqual(mock.mock.calls[0], ['firstArg', 42]);
  assert.deepStrictEqual(mock.mock.lastCall, ['firstArg', 42]);
}

function testInvocationRecordsAndContext() {
  const contextObj = { scope: 'test-scope' };
  const mock = fn(function (factor) {
    return factor * 10;
  });

  const returnedVal = mock.call(contextObj, 5);
  assert.strictEqual(returnedVal, 50);
  assert.strictEqual(mock.mock.calls.length, 1);
  assert.deepStrictEqual(mock.mock.calls[0], [5]);
  assert.strictEqual(mock.mock.contexts[0], contextObj);
  assert.strictEqual(mock.mock.results.length, 1);
  assert.strictEqual(mock.mock.results[0].type, 'return');
  assert.strictEqual(mock.mock.results[0].value, 50);

  const errorMock = fn(() => {
    throw new Error('intentional failure');
  });

  assert.throws(() => errorMock(), /intentional failure/);
  assert.strictEqual(errorMock.mock.results[0].type, 'throw');
  assert.strictEqual(errorMock.mock.results[0].value.message, 'intentional failure');
}

function testReturnValuesConfiguration() {
  const mock = fn();
  mock.mockReturnValue('fallback');
  mock.mockReturnValueOnce('one');
  mock.mockReturnValueOnce('two');

  assert.strictEqual(mock(), 'one');
  assert.strictEqual(mock(), 'two');
  assert.strictEqual(mock(), 'fallback');
  assert.strictEqual(mock(), 'fallback');
}

async function testAsyncResolvedValues() {
  const mock = fn();
  mock.mockResolvedValue('default-async');
  mock.mockResolvedValueOnce('first-async');

  const res1 = await mock();
  assert.strictEqual(res1, 'first-async');

  const res2 = await mock();
  assert.strictEqual(res2, 'default-async');

  const helperMock = createAsyncMock('helper-async');
  const helperRes = await helperMock();
  assert.strictEqual(helperRes, 'helper-async');
}

async function testAsyncRejectedValues() {
  const mock = fn();
  mock.mockRejectedValue(new Error('default-async-error'));
  mock.mockRejectedValueOnce(new Error('first-async-error'));

  await assert.rejects(async () => {
    await mock();
  }, {
    name: 'Error',
    message: 'first-async-error'
  });

  await assert.rejects(async () => {
    await mock();
  }, {
    name: 'Error',
    message: 'default-async-error'
  });

  const rejectingHelper = createRejectingMock(new Error('helper-reject'));
  await assert.rejects(async () => {
    await rejectingHelper();
  }, {
    name: 'Error',
    message: 'helper-reject'
  });
}

function testImplementationChaining() {
  const mock = fn(() => 'base');
  mock.mockImplementationOnce(() => 'temp1');
  mock.mockImplementationOnce(() => 'temp2');
  mock.mockImplementation((x) => `custom-${x}`);

  assert.strictEqual(mock('a'), 'temp1');
  assert.strictEqual(mock('b'), 'temp2');
  assert.strictEqual(mock('c'), 'custom-c');
  assert.strictEqual(mock('d'), 'custom-d');
}

function testMockReturnThis() {
  const mock = fn();
  mock.mockReturnThis();

  const receiver = {
    action: mock
  };

  const chained = receiver.action();
  assert.strictEqual(chained, receiver, 'mockReturnThis must return the execution context');

  const helperChain = createChainableMock();
  const host = { chain: helperChain };
  assert.strictEqual(host.chain(), host);
}

function testMockClear() {
  const mock = fn((val) => val * 3);
  assert.strictEqual(mock(4), 12);
  assert.strictEqual(mock.mock.calls.length, 1);
  assert.strictEqual(mock.mock.results.length, 1);

  mock.mockClear();

  assert.strictEqual(mock.mock.calls.length, 0);
  assert.strictEqual(mock.mock.results.length, 0);
  assert.strictEqual(mock.mock.instances.length, 0);
  assert.strictEqual(mock.mock.contexts.length, 0);

  // Implementation remains intact
  assert.strictEqual(mock(5), 15);
  assert.strictEqual(mock.mock.calls.length, 1);
}

function testMockReset() {
  const mock = fn((val) => val * 3);
  assert.strictEqual(mock(4), 12);

  mock.mockReset();

  assert.strictEqual(mock.mock.calls.length, 0);
  assert.strictEqual(mock.mock.results.length, 0);
  // Implementation reset to empty function returning undefined
  assert.strictEqual(mock(5), undefined);
}

function testWithImplementation() {
  const mock = fn(() => 'original');
  let innerResult;

  mock.withImplementation(() => 'override', () => {
    innerResult = mock();
  });

  assert.strictEqual(innerResult, 'override');
  assert.strictEqual(mock(), 'original');
}

function testSequenceAndInspectHelpers() {
  const sequenceMock = createSequenceMock(['alpha', 'beta'], 'omega');
  assert.strictEqual(sequenceMock(), 'alpha');
  assert.strictEqual(sequenceMock(), 'beta');
  assert.strictEqual(sequenceMock(), 'omega');
  assert.strictEqual(sequenceMock(), 'omega');

  const customNamed = createMockFunction();
  customNamed.mockName('inspectedMock');
  customNamed('arg1', 'arg2');

  const stats = inspectMock(customNamed);
  assert.strictEqual(stats.name, 'inspectedMock');
  assert.strictEqual(stats.callCount, 1);
  assert.deepStrictEqual(stats.calls, [['arg1', 'arg2']]);
  assert.deepStrictEqual(stats.lastCall, ['arg1', 'arg2']);
  assert.strictEqual(stats.results[0].type, 'return');
}

async function runAll() {
  testDefaultMockBehavior();
  testInvocationRecordsAndContext();
  testReturnValuesConfiguration();
  await testAsyncResolvedValues();
  await testAsyncRejectedValues();
  testImplementationChaining();
  testMockReturnThis();
  testMockClear();
  testMockReset();
  testWithImplementation();
  testSequenceAndInspectHelpers();

  console.log('Contract tests passed successfully.');
}

runAll().catch((err) => {
  console.error('Contract test failure:', err);
  process.exit(1);
});

Seeder de origen

anónimo