@vitest/expect 4.1.11

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 pkg:npm/%40vitest/expect@4.1.11
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40vitest/expect@4.1.11

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:sha256:398260778990bbae44d585704bee6b0697c5dbfee5b9c9d3ee245e5dc684b94a","contract":["expect performs strict primitive equality, boolean/nullish checks, and .not negation","toEqual and toStrictEqual perform deep structural equality assertions on objects and arrays","toMatchObject and toHaveProperty verify subset structures and nested object properties","toContain and toContainEqual assert collection containment and element equality","toBeGreaterThan, toBeLessThan, and toBeCloseTo validate numeric relationships and floating point values","toBeTypeOf and toBeInstanceOf evaluate type classifications and instance constructors","toSatisfy and toBeOneOf custom matchers evaluate predicate functions and element membership","toThrow verifies exception throwing and error type matching","Asymmetric matchers stringContaining, stringMatching, objectContaining, arrayContaining, any, anything, and closeTo match partial values","SchemaMatching and expect.schemaMatching validate data against Standard Schema V1 definitions","expect.extend registers custom matchers with custom pass and failure message logic","getState and setState inspect and update matcher execution context"],"goal":"verify pkg:npm/%40vitest/expect@4.1.11","kind":"HOW","packages":["pkg:npm/%40vitest/expect@4.1.11"],"schemaVersion":1},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","executionContext":"node","language":"javascript","libc":"glibc","libcVersion":"2.39","moduleSystem":"esm","os":"linux","osVersionBucket":"24","packageManager":"npm","packageManagerVersion":"10.9.8","runtime":"node","runtimeVersion":"22.23.2","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/%40vitest/expect@4.1.11"],"schemaVersion":1,"subject":"pkg:npm/%40vitest/expect@4.1.11","verifierAdapter":"node-typescript@1"}

import * as chai from 'chai';
import {
  JestChaiExpect,
  JestAsymmetricMatchers,
  JestExtend,
  ChaiStyleAssertions,
  customMatchers,
  getState,
  setState,
  equals,
  isA,
  isAsymmetric,
  hasAsymmetric,
  isStandardSchema,
  StringContaining,
  StringMatching,
  ObjectContaining,
  ArrayContaining,
  Any,
  Anything,
  SchemaMatching,
  addCustomEqualityTesters
} from '@vitest/expect';

chai.use(JestChaiExpect);
chai.use(JestAsymmetricMatchers);
chai.use(JestExtend);
chai.use(ChaiStyleAssertions);

chai.expect.extend(chai.expect, customMatchers);

export const expect = chai.expect;

export {
  chai,
  JestChaiExpect,
  JestAsymmetricMatchers,
  JestExtend,
  ChaiStyleAssertions,
  customMatchers,
  getState,
  setState,
  equals,
  isA,
  isAsymmetric,
  hasAsymmetric,
  isStandardSchema,
  StringContaining,
  StringMatching,
  ObjectContaining,
  ArrayContaining,
  Any,
  Anything,
  SchemaMatching,
  addCustomEqualityTesters
};

{
  "name": "sample-vitest-expect",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-vitest-expect",
      "version": "1.0.0",
      "dependencies": {
        "@vitest/expect": "4.1.11"
      }
    },
    "node_modules/@standard-schema/spec": {
      "version": "1.1.0",
      "resolved": "https://registry.npmjs.org/@standard-schema/spec/-/spec-1.1.0.tgz",
      "integrity": "sha512-l2aFy5jALhniG5HgqrD6jXLi/rUWrKvqN/qJx6yoJsgKhblVd+iqqU4RCXavm/jPityDo5TCvKMnpjKnOriy0w==",
      "license": "MIT"
    },
    "node_modules/@types/chai": {
      "version": "5.2.3",
      "resolved": "https://registry.npmjs.org/@types/chai/-/chai-5.2.3.tgz",
      "integrity": "sha512-Mw558oeA9fFbv65/y4mHtXDs9bPnFMZAL/jxdPFUpOHHIXX91mcgEHbS5Lahr+pwZFR8A7GQleRWeI6cGFC2UA==",
      "license": "MIT",
      "dependencies": {
        "@types/deep-eql": "*",
        "assertion-error": "^2.0.1"
      }
    },
    "node_modules/@types/deep-eql": {
      "version": "4.0.2",
      "resolved": "https://registry.npmjs.org/@types/deep-eql/-/deep-eql-4.0.2.tgz",
      "integrity": "sha512-c9h9dVVMigMPc4bwTvC5dxqtqJZwQPePsWjPlpSOnojbor6pGqdk541lfA7AqFQr5pB1BRdq0juY9db81BwyFw==",
      "license": "MIT"
    },
    "node_modules/@vitest/expect": {
      "version": "4.1.11",
      "resolved": "https://registry.npmjs.org/@vitest/expect/-/expect-4.1.11.tgz",
      "integrity": "sha512-VX2x5vNJXET47KAFzwERI+KRMtTTCSWTfSMKsW7JsUsXV4psq++e3DvZpuTDOpHcxytiDs6p2nhVb2tVDiiUYw==",
      "license": "MIT",
      "dependencies": {
        "@standard-schema/spec": "^1.1.0",
        "@types/chai": "^5.2.2",
        "@vitest/spy": "4.1.11",
        "@vitest/utils": "4.1.11",
        "chai": "^6.2.2",
        "tinyrainbow": "^3.1.0"
      },
      "funding": {
        "url": "https://opencollective.com/vitest"
      }
    },
    "node_modules/@vitest/pretty-format": {
      "version": "4.1.11",
      "resolved": "https://registry.npmjs.org/@vitest/pretty-format/-/pretty-format-4.1.11.tgz",
      "integrity": "sha512-yiZzPbGTS9Sr/JpFl8zHrcIkAofNbFV6k21vIgQN/cY/oxZeXhJv5sc/MBJ5jFKWmWs+oJHw0UXLZjmf931+Vw==",
      "license": "MIT",
      "dependencies": {
        "tinyrainbow": "^3.1.0"
      },
      "funding": {
        "url": "https://opencollective.com/vitest"
      }
    },
    "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/@vitest/utils": {
      "version": "4.1.11",
      "resolved": "https://registry.npmjs.org/@vitest/utils/-/utils-4.1.11.tgz",
      "integrity": "sha512-zTCVGpyFsGWBhllOyKlTw/vnr6D9qxsfSDyfbyZmTyjHw5N/VuvzHpHoQjm2ZJzn4RJgx5w4r7V0er69CmLgPQ==",
      "license": "MIT",
      "dependencies": {
        "@vitest/pretty-format": "4.1.11",
        "convert-source-map": "^2.0.0",
        "tinyrainbow": "^3.1.0"
      },
      "funding": {
        "url": "https://opencollective.com/vitest"
      }
    },
    "node_modules/assertion-error": {
      "version": "2.0.1",
      "resolved": "https://registry.npmjs.org/assertion-error/-/assertion-error-2.0.1.tgz",
      "integrity": "sha512-Izi8RQcffqCeNVgFigKli1ssklIbpHnCYc6AknXGYoB6grJqyeby7jv12JUQgmTAnIDnbck1uxksT4dzN3PWBA==",
      "license": "MIT",
      "engines": {
        "node": ">=12"
      }
    },
    "node_modules/chai": {
      "version": "6.2.2",
      "resolved": "https://registry.npmjs.org/chai/-/chai-6.2.2.tgz",
      "integrity": "sha512-NUPRluOfOiTKBKvWPtSD4PhFvWCqOi0BGStNWs57X9js7XGTprSmFoz5F0tWhR4WPjNeR9jXqdC7/UpSJTnlRg==",
      "license": "MIT",
      "engines": {
        "node": ">=18"
      }
    },
    "node_modules/convert-source-map": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/convert-source-map/-/convert-source-map-2.0.0.tgz",
      "integrity": "sha512-Kvp459HrV2FEJ1CAsi1Ku+MY3kasH19TFykTz2xWmMeq6bk2NU3XXvfJ+Q61m0xktWwt+1HSYf3JZsTms3aRJg==",
      "license": "MIT"
    },
    "node_modules/tinyrainbow": {
      "version": "3.1.1",
      "resolved": "https://registry.npmjs.org/tinyrainbow/-/tinyrainbow-3.1.1.tgz",
      "integrity": "sha512-yau8yJdTt989Mm0Bd/236QnzEiPf2xLLTqUZRUJOo/3CB078LSwzei343DgtJVmfJKJE3TMINY1u42SQsP6mXw==",
      "license": "MIT",
      "engines": {
        "node": ">=14.0.0"
      }
    }
  }
}

{
  "name": "sample-vitest-expect",
  "version": "1.0.0",
  "description": "Clean-room verification sample for @vitest/expect@4.1.11",
  "type": "module",
  "main": "index.mjs",
  "scripts": {
    "test": "node test/contract.mjs"
  },
  "dependencies": {
    "@vitest/expect": "4.1.11"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/%40vitest/expect@4.1.11",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40vitest/expect@4.1.11"
  ]
}

import assert from 'node:assert/strict';
import {
  expect,
  customMatchers,
  getState,
  setState,
  equals,
  isA,
  isAsymmetric,
  hasAsymmetric,
  isStandardSchema,
  StringContaining,
  StringMatching,
  ObjectContaining,
  ArrayContaining,
  Any,
  Anything,
  SchemaMatching,
  addCustomEqualityTesters
} from '../index.mjs';

// 1. Basic expect assertions and .not negation
{
  assert.equal(typeof expect, 'function');
  expect(42).toBe(42);
  expect('vitest').toBe('vitest');
  expect(true).toBe(true);
  expect(false).toBe(false);
  expect(null).toBeNull();
  expect(undefined).toBeUndefined();
  expect(NaN).toBeNaN();
  expect('value').toBeDefined();
  expect(true).toBeTruthy();
  expect(false).toBeFalsy();
  expect(10).not.toBe(20);
  expect('hello').not.toBe('world');
}

// 2. Deep equality with toEqual and toStrictEqual
{
  const obj1 = { id: 1, tags: ['a', 'b'], meta: { count: 3 } };
  const obj2 = { id: 1, tags: ['a', 'b'], meta: { count: 3 } };
  expect(obj1).toEqual(obj2);
  expect(obj1).toStrictEqual(obj2);
  expect([1, 2, 3]).toEqual([1, 2, 3]);
  expect([1, 2]).not.toEqual([1, 3]);
}

// 3. Object matching and property validation
{
  const user = { id: 100, name: 'Alex', profile: { role: 'admin', level: 5 } };
  expect(user).toMatchObject({ name: 'Alex', profile: { role: 'admin' } });
  expect(user).toHaveProperty('profile.role', 'admin');
  expect(user).toHaveProperty('id', 100);
}

// 4. Collection containment and length checks
{
  expect(['apple', 'banana', 'orange']).toContain('banana');
  expect('javascript string matcher').toContain('string');
  expect([{ key: 'a' }, { key: 'b' }]).toContainEqual({ key: 'b' });
  expect([10, 20, 30]).toHaveLength(3);
  expect('hello').toHaveLength(5);
}

// 5. Numerical comparisons (toBeGreaterThan, toBeLessThan, toBeCloseTo)
{
  expect(15).toBeGreaterThan(10);
  expect(15).toBeGreaterThanOrEqual(15);
  expect(5).toBeLessThan(10);
  expect(5).toBeLessThanOrEqual(5);
  expect(0.1 + 0.2).toBeCloseTo(0.3, 5);
}

// 6. Type assertions, toBeInstanceOf, and customMatchers (toSatisfy, toBeOneOf)
{
  expect('test-string').toBeTypeOf('string');
  expect(12345).toBeTypeOf('number');
  expect(true).toBeTypeOf('boolean');
  expect(Symbol('vitest')).toBeTypeOf('symbol');
  expect(new Date()).toBeInstanceOf(Date);
  expect(20).toSatisfy(n => n % 5 === 0);
  expect('admin@example.com').toSatisfy(s => s.includes('@'));
  expect('banana').toBeOneOf(['apple', 'banana', 'orange']);
  expect(2).toBeOneOf([1, 2, 3]);
}

// 7. Error handling assertions with toThrow
{
  expect(() => {
    throw new Error('invalid operation');
  }).toThrow('invalid operation');

  expect(() => {
    throw new TypeError('invalid argument');
  }).toThrow(TypeError);

  expect(() => {
    // normal execution
  }).not.toThrow();
}

// 8. Asymmetric matchers via expect properties and constructors
{
  expect('sample-test-case').toEqual(expect.stringContaining('test'));
  expect('vitest-4.1.11').toEqual(expect.stringMatching(/^vitest-\d+\.\d+\.\d+$/));
  expect({ x: 1, y: 2, extra: true }).toEqual(expect.objectContaining({ x: 1, y: 2 }));
  expect([1, 2, 3, 4]).toEqual(expect.arrayContaining([2, 4]));
  expect('hello').toEqual(expect.any(String));
  expect(99).toEqual(expect.any(Number));
  expect({ custom: true }).toEqual(expect.anything());
  expect(5.119).toEqual(expect.closeTo(5.12, 1));

  // Direct asymmetric matcher classes
  expect('prefix-val-suffix').toEqual(new StringContaining('val'));
  expect('abc-123').toEqual(new StringMatching(/^abc-\d+$/));
  expect({ a: 10, b: 20 }).toEqual(new ObjectContaining({ a: 10 }));
  expect([10, 20, 30]).toEqual(new ArrayContaining([20]));
  expect('str').toEqual(new Any(String));
  expect({}).toEqual(new Anything());
}

// 9. Standard Schema integration with schemaMatching
{
  const mockStandardSchema = {
    '~standard': {
      version: 1,
      vendor: 'test-vendor',
      validate: value => {
        if (typeof value === 'string' && value.startsWith('valid-')) {
          return { value };
        }
        return { issues: [{ message: 'Expected prefix valid-' }] };
      }
    }
  };

  assert.equal(isStandardSchema(mockStandardSchema), true);
  expect('valid-data').toEqual(expect.schemaMatching(mockStandardSchema));
  expect('valid-custom').toEqual(new SchemaMatching(mockStandardSchema));
}

// 10. Custom matcher registration with expect.extend
{
  expect.extend(expect, {
    toBeWithinRange(received, floor, ceiling) {
      const pass = received >= floor && received <= ceiling;
      return {
        pass,
        message: () => `expected ${received} ${pass ? 'not ' : ''}to be within range [${floor}, ${ceiling}]`,
      };
    },
  });

  expect(50).toBeWithinRange(1, 100);
  expect(150).not.toBeWithinRange(1, 100);
}

// 11. State management (getState, setState) and matcher utilities
{
  setState({ currentTestName: 'vitest-expect-contract-test', assertionCalls: 15 }, expect);
  const state = getState(expect);
  assert.equal(state.currentTestName, 'vitest-expect-contract-test');
  assert.equal(state.assertionCalls, 15);

  assert.equal(equals({ k: 1 }, { k: 1 }), true);
  assert.equal(equals({ k: 1 }, { k: 2 }), false);
  assert.equal(isA('String', 'hello'), true);
  assert.equal(isA('Number', 42), true);
  assert.equal(isAsymmetric(new Any(String)), true);
  assert.equal(hasAsymmetric({ matcher: new Any(Number) }), true);
}

console.log('All @vitest/expect contract assertions passed successfully.');