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Beispiel

expect 29.7.0: custom matchers and asymmetric matching with expect.extend

Verifiziertes Beispiel für npm expect 29.7.0: custom matchers and asymmetric matching with expect.extend. Der Vertrag lief auf node 22 · linux alpine/x64 …

sha256:01f9c6abdcb96a68d18b7023636cb7ec313499a3b4c550176442363638e97ac0

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Ausführungsbelege

Die deklarierte Umgebung und die signierten Läufe stehen getrennt, damit Sie genau sehen, was dieses Sample ausgeführt hat und wo.

Beleggrundlage
Signierter Vertrag bestanden
Verifizierungsbelege
1
Signaturschlüssel, die es gebaut haben
1
Deklarierte Umgebung node 22.23 linux 24 · ubuntu · glibc 2.39 x64 node 22.23 javascript npm 10

Umgebungen der Verifizierungsläufe

Umgebung Contract Stufen Lauf
node 22 · linux alpine/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1node:22-alpine@sha256:c610fcdfb1d5…		 2026-08-26

Fall

HOW
Ziel
custom matchers and asymmetric matching with expect.extend
Pakete
Symbole
  • expect.extend
Umgebung
node 22.23.2
Erstellt
2026-08-26T06:45:20Z

Contract

  1. expect.extend registers synchronous custom matchers that pass on satisfaction and throw descriptive error messages on failure
  2. expect.extend custom matchers support .not negation modifier
  3. expect.extend registers asynchronous custom matchers returning Promises that resolve with pass and failure message
  4. expect supports asymmetric matchers objectContaining, arrayContaining, stringContaining, stringMatching, and any with toEqual
  5. expect.addEqualityTesters registers custom equality comparators for deep equality checks
  6. expect.getState and expect.setState manage expectation context state
  7. expect.assertions and expect.hasAssertions track executed assertion count
  8. expect supports resolves and rejects promise assertion modifiers

Dateien

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

Quellartefakt herunterladen (tar.gz)

Quelltext

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: custom matchers and asymmetric matching with expect.extend
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/expect@29.7.0
Demonstrate these symbols/APIs:
  - expect.extend

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:sha256:289faef74a15e2b8f425ddb770dc220ca9c3b72363efec58d8a51ba007eccce6","constraints":{"executionContext":"node"},"contract":["expect.extend registers synchronous custom matchers that pass on satisfaction and throw descriptive error messages on failure","expect.extend custom matchers support .not negation modifier","expect.extend registers asynchronous custom matchers returning Promises that resolve with pass and failure message","expect supports asymmetric matchers objectContaining, arrayContaining, stringContaining, stringMatching, and any with toEqual","expect.addEqualityTesters registers custom equality comparators for deep equality checks","expect.getState and expect.setState manage expectation context state","expect.assertions and expect.hasAssertions track executed assertion count","expect supports resolves and rejects promise assertion modifiers"],"goal":"custom matchers and asymmetric matching with expect.extend","kind":"HOW","packages":["pkg:npm/expect@29.7.0"],"schemaVersion":1,"symbols":["expect.extend"]},"contractCommand":["node","test/contract.mjs"],"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/expect@29.7.0"],"schemaVersion":1,"subject":"pkg:npm/expect@29.7.0","symbols":["expect.extend"],"verifierAdapter":"node-typescript@1"}
index.mjs
import { expect } from 'expect';

/**
 * Custom matchers for numeric ranges, divisibility, and ISO date strings.
 */
export const customMatchers = {
  toBeWithinRange(received, floor, ceiling) {
    const pass = typeof received === 'number' && received >= floor && received <= ceiling;
    return {
      pass,
      message: () =>
        pass
          ? `expected ${received} not to be within range [${floor}, ${ceiling}]`
          : `expected ${received} to be within range [${floor}, ${ceiling}]`
    };
  },
  toBeDivisibleBy(received, divisor) {
    const pass =
      typeof received === 'number' &&
      typeof divisor === 'number' &&
      divisor !== 0 &&
      received % divisor === 0;
    return {
      pass,
      message: () =>
        pass
          ? `expected ${received} not to be divisible by ${divisor}`
          : `expected ${received} to be divisible by ${divisor}`
    };
  },
  toBeValidIsoDate(received) {
    const isString = typeof received === 'string';
    const parsed = isString ? Date.parse(received) : NaN;
    const pass = !Number.isNaN(parsed) && new Date(parsed).toISOString() === received;
    return {
      pass,
      message: () =>
        pass
          ? `expected ${received} not to be a valid ISO 8601 date string`
          : `expected ${received} to be a valid ISO 8601 date string`
    };
  },
  async toBeResolvedWithStatus(receivedPromise, expectedStatus) {
    const resolved = await receivedPromise;
    const pass = resolved !== null && typeof resolved === 'object' && resolved.status === expectedStatus;
    return {
      pass,
      message: () =>
        pass
          ? `expected promise not to resolve with status ${expectedStatus}`
          : `expected promise to resolve with status ${expectedStatus}, received ${resolved ? resolved.status : resolved}`
    };
  }
};

/**
 * Registers custom matchers into expect using expect.extend.
 * @param {Record<string, Function>} [matchers]
 */
export function registerCustomMatchers(matchers = customMatchers) {
  expect.extend(matchers);
}

/**
 * Validates a structured object with asymmetric matchers.
 * @param {object} payload
 * @returns {boolean}
 */
export function validatePayload(payload) {
  expect(payload).toEqual(
    expect.objectContaining({
      id: expect.any(Number),
      name: expect.any(String),
      tags: expect.arrayContaining(['active']),
      metadata: expect.objectContaining({
        version: expect.stringMatching(/^\d+\.\d+$/)
      })
    })
  );
  return true;
}

export { expect };
package-lock.json
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package.json
{
  "name": "sample-expect-extend",
  "version": "1.0.0",
  "description": "Clean-room verification sample for expect custom matchers with expect.extend",
  "type": "module",
  "main": "index.mjs",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "expect": "29.7.0"
  },
  "license": "MIT-0"
}
spec.json
{
  "schemaVersion": 1,
  "goal": "custom matchers and asymmetric matching with expect.extend",
  "kind": "HOW",
  "packages": [
    "pkg:npm/expect@29.7.0"
  ],
  "symbols": [
    "expect.extend"
  ]
}
test/contract.mjs
import assert from 'node:assert';
import {
  expect,
  customMatchers,
  registerCustomMatchers,
  validatePayload
} from '../index.mjs';

function testExtendRegistersSyncMatchers() {
  registerCustomMatchers();

  // Passing assertions
  expect(15).toBeWithinRange(10, 20);
  expect(10).toBeWithinRange(10, 20);
  expect(20).toBeWithinRange(10, 20);
  expect(12).toBeDivisibleBy(4);
  expect('2026-08-26T00:00:00.000Z').toBeValidIsoDate();

  // Failing assertions throw with expected message
  assert.throws(
    () => {
      expect(25).toBeWithinRange(10, 20);
    },
    (err) => {
      assert.ok(err.message.includes('expected 25 to be within range [10, 20]'));
      return true;
    }
  );

  assert.throws(
    () => {
      expect(13).toBeDivisibleBy(5);
    },
    (err) => {
      assert.ok(err.message.includes('expected 13 to be divisible by 5'));
      return true;
    }
  );

  assert.throws(
    () => {
      expect('not-a-date').toBeValidIsoDate();
    },
    (err) => {
      assert.ok(err.message.includes('expected not-a-date to be a valid ISO 8601 date string'));
      return true;
    }
  );
}

function testExtendSupportsNotModifier() {
  registerCustomMatchers();

  // Inverted passing assertions
  expect(5).not.toBeWithinRange(10, 20);
  expect(25).not.toBeWithinRange(10, 20);
  expect(13).not.toBeDivisibleBy(5);
  expect('invalid-iso-string').not.toBeValidIsoDate();

  // Inverted failing assertion throws
  assert.throws(
    () => {
      expect(15).not.toBeWithinRange(10, 20);
    },
    (err) => {
      assert.ok(err.message.includes('expected 15 not to be within range [10, 20]'));
      return true;
    }
  );
}

async function testExtendRegistersAsyncMatchers() {
  registerCustomMatchers();

  // Async matcher resolves pass
  await expect(Promise.resolve({ status: 200, body: 'ok' })).toBeResolvedWithStatus(200);

  // Async matcher with .not
  await expect(Promise.resolve({ status: 404, body: 'not found' })).not.toBeResolvedWithStatus(200);

  // Async failure throws with message
  let errorCaught = false;
  try {
    await expect(Promise.resolve({ status: 500 })).toBeResolvedWithStatus(200);
  } catch (err) {
    errorCaught = true;
    assert.ok(err.message.includes('expected promise to resolve with status 200, received 500'));
  }
  assert.strictEqual(errorCaught, true, 'Async matcher failure must throw error');
}

function testAsymmetricMatchers() {
  const payload = {
    id: 101,
    name: 'alpha-service',
    tags: ['active', 'internal'],
    metadata: {
      version: '2.5',
      environment: 'production'
    }
  };

  const validated = validatePayload(payload);
  assert.strictEqual(validated, true);

  expect(payload).toEqual(
    expect.objectContaining({
      id: expect.any(Number),
      name: expect.stringContaining('alpha'),
      tags: expect.arrayContaining(['internal'])
    })
  );

  expect('sample-identifier-99').toEqual(expect.stringMatching(/^sample-[a-z]+-\d+$/));
  expect(true).toEqual(expect.anything());

  // Inverted asymmetric matchers
  expect('unrelated-value').toEqual(expect.not.stringContaining('alpha'));
  expect(['a', 'b']).toEqual(expect.not.arrayContaining(['z']));
}

function testAddEqualityTesters() {
  class CustomId {
    constructor(val) {
      this.val = val;
    }
  }

  function customIdTester(a, b) {
    if (a instanceof CustomId && b instanceof CustomId) {
      return a.val === b.val;
    }
    return undefined;
  }

  expect.addEqualityTesters([customIdTester]);

  const id1 = new CustomId('item-42');
  const id2 = new CustomId('item-42');
  const id3 = new CustomId('item-99');

  expect({ id: id1 }).toEqual({ id: id2 });
  assert.throws(() => {
    expect({ id: id1 }).toEqual({ id: id3 });
  });
}

function testStateManagementAndAssertions() {
  const initialState = expect.getState();
  assert.ok(typeof initialState === 'object');

  expect.setState({ customTestTag: 'unit-contract-test' });
  const updatedState = expect.getState();
  assert.strictEqual(updatedState.customTestTag, 'unit-contract-test');

  expect.hasAssertions();
  expect.assertions(1);
  expect(42).toBe(42);
}

async function testResolvesAndRejectsModifiers() {
  await expect(Promise.resolve('expected-result')).resolves.toBe('expected-result');
  await expect(Promise.reject(new Error('operational error'))).rejects.toThrow('operational error');
}

async function runAll() {
  testExtendRegistersSyncMatchers();
  testExtendSupportsNotModifier();
  await testExtendRegistersAsyncMatchers();
  testAsymmetricMatchers();
  testAddEqualityTesters();
  testStateManagementAndAssertions();
  await testResolvesAndRejectsModifiers();

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

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

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