/** * The `node:test` module facilitates the creation of JavaScript tests. * To access it: * * ```js * import test from 'node:test'; * ``` * * This module is only available under the `node:` scheme. The following will not * work: * * ```js * import test from 'test'; * ``` * * Tests created via the `test` module consist of a single function that is * processed in one of three ways: * * 1. A synchronous function that is considered failing if it throws an exception, * and is considered passing otherwise. * 2. A function that returns a `Promise` that is considered failing if the`Promise` rejects, and is considered passing if the `Promise` fulfills. * 3. A function that receives a callback function. If the callback receives any * truthy value as its first argument, the test is considered failing. If a * falsy value is passed as the first argument to the callback, the test is * considered passing. If the test function receives a callback function and * also returns a `Promise`, the test will fail. * * The following example illustrates how tests are written using the`test` module. * * ```js * test('synchronous passing test', (t) => { * // This test passes because it does not throw an exception. * assert.strictEqual(1, 1); * }); * * test('synchronous failing test', (t) => { * // This test fails because it throws an exception. * assert.strictEqual(1, 2); * }); * * test('asynchronous passing test', async (t) => { * // This test passes because the Promise returned by the async * // function is settled and not rejected. * assert.strictEqual(1, 1); * }); * * test('asynchronous failing test', async (t) => { * // This test fails because the Promise returned by the async * // function is rejected. * assert.strictEqual(1, 2); * }); * * test('failing test using Promises', (t) => { * // Promises can be used directly as well. * return new Promise((resolve, reject) => { * setImmediate(() => { * reject(new Error('this will cause the test to fail')); * }); * }); * }); * * test('callback passing test', (t, done) => { * // done() is the callback function. When the setImmediate() runs, it invokes * // done() with no arguments. * setImmediate(done); * }); * * test('callback failing test', (t, done) => { * // When the setImmediate() runs, done() is invoked with an Error object and * // the test fails. * setImmediate(() => { * done(new Error('callback failure')); * }); * }); * ``` * * If any tests fail, the process exit code is set to `1`. * @since v18.0.0, v16.17.0 * @see [source](https://github.com/nodejs/node/blob/v20.4.0/lib/test.js) */ declare module "node:test" { import { Readable } from "node:stream"; import { AsyncResource } from "node:async_hooks"; /** * **Note:**`shard` is used to horizontally parallelize test running across * machines or processes, ideal for large-scale executions across varied * environments. It's incompatible with `watch` mode, tailored for rapid * code iteration by automatically rerunning tests on file changes. * * ```js * import { tap } from 'node:test/reporters'; * import { run } from 'node:test'; * import process from 'node:process'; * import path from 'node:path'; * * run({ files: [path.resolve('./tests/test.js')] }) * .compose(tap) * .pipe(process.stdout); * ``` * @since v18.9.0, v16.19.0 * @param options Configuration options for running tests. The following properties are supported: */ function run(options?: RunOptions): TestsStream; /** * The `test()` function is the value imported from the `test` module. Each * invocation of this function results in reporting the test to the `TestsStream`. * * The `TestContext` object passed to the `fn` argument can be used to perform * actions related to the current test. Examples include skipping the test, adding * additional diagnostic information, or creating subtests. * * `test()` returns a `Promise` that fulfills once the test completes. * if `test()` is called within a `describe()` block, it fulfills immediately. * The return value can usually be discarded for top level tests. * However, the return value from subtests should be used to prevent the parent * test from finishing first and cancelling the subtest * as shown in the following example. * * ```js * test('top level test', async (t) => { * // The setTimeout() in the following subtest would cause it to outlive its * // parent test if 'await' is removed on the next line. Once the parent test * // completes, it will cancel any outstanding subtests. * await t.test('longer running subtest', async (t) => { * return new Promise((resolve, reject) => { * setTimeout(resolve, 1000); * }); * }); * }); * ``` * * The `timeout` option can be used to fail the test if it takes longer than`timeout` milliseconds to complete. However, it is not a reliable mechanism for * canceling tests because a running test might block the application thread and * thus prevent the scheduled cancellation. * @since v18.0.0, v16.17.0 * @param [name='The name'] The name of the test, which is displayed when reporting test results. * @param options Configuration options for the test. The following properties are supported: * @param [fn='A no-op function'] The function under test. The first argument to this function is a {@link TestContext} object. If the test uses callbacks, the callback function is passed as the * second argument. * @return Fulfilled with `undefined` once the test completes, or immediately if the test runs within {@link describe}. */ function test(name?: string, fn?: TestFn): Promise; function test(name?: string, options?: TestOptions, fn?: TestFn): Promise; function test(options?: TestOptions, fn?: TestFn): Promise; function test(fn?: TestFn): Promise; namespace test { export { after, afterEach, before, beforeEach, describe, it, mock, only, run, skip, test, todo }; } /** * The `describe()` function imported from the `node:test` module. Each * invocation of this function results in the creation of a Subtest. * After invocation of top level `describe` functions, * all top level tests and suites will execute. * @param [name='The name'] The name of the suite, which is displayed when reporting test results. * @param options Configuration options for the suite. supports the same options as `test([name][, options][, fn])`. * @param [fn='A no-op function'] The function under suite declaring all subtests and subsuites. The first argument to this function is a {@link SuiteContext} object. * @return Immediately fulfilled with `undefined`. */ function describe(name?: string, options?: TestOptions, fn?: SuiteFn): Promise; function describe(name?: string, fn?: SuiteFn): Promise; function describe(options?: TestOptions, fn?: SuiteFn): Promise; function describe(fn?: SuiteFn): Promise; namespace describe { /** * Shorthand for skipping a suite, same as `describe([name], { skip: true }[, fn])`. */ function skip(name?: string, options?: TestOptions, fn?: SuiteFn): Promise; function skip(name?: string, fn?: SuiteFn): Promise; function skip(options?: TestOptions, fn?: SuiteFn): Promise; function skip(fn?: SuiteFn): Promise; /** * Shorthand for marking a suite as `TODO`, same as `describe([name], { todo: true }[, fn])`. */ function todo(name?: string, options?: TestOptions, fn?: SuiteFn): Promise; function todo(name?: string, fn?: SuiteFn): Promise; function todo(options?: TestOptions, fn?: SuiteFn): Promise; function todo(fn?: SuiteFn): Promise; /** * Shorthand for marking a suite as `only`, same as `describe([name], { only: true }[, fn])`. * @since v18.15.0 */ function only(name?: string, options?: TestOptions, fn?: SuiteFn): Promise; function only(name?: string, fn?: SuiteFn): Promise; function only(options?: TestOptions, fn?: SuiteFn): Promise; function only(fn?: SuiteFn): Promise; } /** * Shorthand for `test()`. * * The `it()` function is imported from the `node:test` module. * @since v18.6.0, v16.17.0 */ function it(name?: string, options?: TestOptions, fn?: TestFn): Promise; function it(name?: string, fn?: TestFn): Promise; function it(options?: TestOptions, fn?: TestFn): Promise; function it(fn?: TestFn): Promise; namespace it { /** * Shorthand for skipping a test, same as `it([name], { skip: true }[, fn])`. */ function skip(name?: string, options?: TestOptions, fn?: TestFn): Promise; function skip(name?: string, fn?: TestFn): Promise; function skip(options?: TestOptions, fn?: TestFn): Promise; function skip(fn?: TestFn): Promise; /** * Shorthand for marking a test as `TODO`, same as `it([name], { todo: true }[, fn])`. */ function todo(name?: string, options?: TestOptions, fn?: TestFn): Promise; function todo(name?: string, fn?: TestFn): Promise; function todo(options?: TestOptions, fn?: TestFn): Promise; function todo(fn?: TestFn): Promise; /** * Shorthand for marking a test as `only`, same as `it([name], { only: true }[, fn])`. * @since v18.15.0 */ function only(name?: string, options?: TestOptions, fn?: TestFn): Promise; function only(name?: string, fn?: TestFn): Promise; function only(options?: TestOptions, fn?: TestFn): Promise; function only(fn?: TestFn): Promise; } /** * Shorthand for skipping a test, same as `test([name], { skip: true }[, fn])`. * @since v20.2.0 */ function skip(name?: string, options?: TestOptions, fn?: TestFn): Promise; function skip(name?: string, fn?: TestFn): Promise; function skip(options?: TestOptions, fn?: TestFn): Promise; function skip(fn?: TestFn): Promise; /** * Shorthand for marking a test as `TODO`, same as `test([name], { todo: true }[, fn])`. * @since v20.2.0 */ function todo(name?: string, options?: TestOptions, fn?: TestFn): Promise; function todo(name?: string, fn?: TestFn): Promise; function todo(options?: TestOptions, fn?: TestFn): Promise; function todo(fn?: TestFn): Promise; /** * Shorthand for marking a test as `only`, same as `test([name], { only: true }[, fn])`. * @since v20.2.0 */ function only(name?: string, options?: TestOptions, fn?: TestFn): Promise; function only(name?: string, fn?: TestFn): Promise; function only(options?: TestOptions, fn?: TestFn): Promise; function only(fn?: TestFn): Promise; /** * The type of a function under test. The first argument to this function is a * {@link TestContext} object. If the test uses callbacks, the callback function is passed as * the second argument. */ type TestFn = (t: TestContext, done: (result?: any) => void) => void | Promise; /** * The type of a function under Suite. */ type SuiteFn = (s: SuiteContext) => void | Promise; interface TestShard { /** * A positive integer between 1 and `` that specifies the index of the shard to run. */ index: number; /** * A positive integer that specifies the total number of shards to split the test files to. */ total: number; } interface RunOptions { /** * If a number is provided, then that many files would run in parallel. * If truthy, it would run (number of cpu cores - 1) files in parallel. * If falsy, it would only run one file at a time. * If unspecified, subtests inherit this value from their parent. * @default true */ concurrency?: number | boolean | undefined; /** * An array containing the list of files to run. * If unspecified, the test runner execution model will be used. */ files?: readonly string[] | undefined; /** * Allows aborting an in-progress test execution. * @default undefined */ signal?: AbortSignal | undefined; /** * A number of milliseconds the test will fail after. * If unspecified, subtests inherit this value from their parent. * @default Infinity */ timeout?: number | undefined; /** * Sets inspector port of test child process. * If a nullish value is provided, each process gets its own port, * incremented from the primary's `process.debugPort`. */ inspectPort?: number | (() => number) | undefined; /** * That can be used to only run tests whose name matches the provided pattern. * Test name patterns are interpreted as JavaScript regular expressions. * For each test that is executed, any corresponding test hooks, such as `beforeEach()`, are also run. */ testNamePatterns?: string | RegExp | string[] | RegExp[]; /** * If truthy, the test context will only run tests that have the `only` option set */ only?: boolean; /** * A function that accepts the TestsStream instance and can be used to setup listeners before any tests are run. */ setup?: (root: Test) => void | Promise; /** * Whether to run in watch mode or not. * @default false */ watch?: boolean | undefined; /** * Running tests in a specific shard. * @default undefined */ shard?: TestShard | undefined; } class Test extends AsyncResource { concurrency: number; nesting: number; only: boolean; reporter: TestsStream; runOnlySubtests: boolean; testNumber: number; timeout: number | null; } /** * A successful call to `run()` method will return a new `TestsStream` object, streaming a series of events representing the execution of the tests.`TestsStream` will emit events, in the * order of the tests definition * @since v18.9.0, v16.19.0 */ class TestsStream extends Readable implements NodeJS.ReadableStream { addListener(event: "test:diagnostic", listener: (data: DiagnosticData) => void): this; addListener(event: "test:fail", listener: (data: TestFail) => void): this; addListener(event: "test:pass", listener: (data: TestPass) => void): this; addListener(event: "test:plan", listener: (data: TestPlan) => void): this; addListener(event: "test:start", listener: (data: TestStart) => void): this; addListener(event: "test:stderr", listener: (data: TestStderr) => void): this; addListener(event: "test:stdout", listener: (data: TestStdout) => void): this; addListener(event: string, listener: (...args: any[]) => void): this; emit(event: "test:diagnostic", data: DiagnosticData): boolean; emit(event: "test:fail", data: TestFail): boolean; emit(event: "test:pass", data: TestPass): boolean; emit(event: "test:plan", data: TestPlan): boolean; emit(event: "test:start", data: TestStart): boolean; emit(event: "test:stderr", data: TestStderr): boolean; emit(event: "test:stdout", data: TestStdout): boolean; emit(event: string | symbol, ...args: any[]): boolean; on(event: "test:diagnostic", listener: (data: DiagnosticData) => void): this; on(event: "test:fail", listener: (data: TestFail) => void): this; on(event: "test:pass", listener: (data: TestPass) => void): this; on(event: "test:plan", listener: (data: TestPlan) => void): this; on(event: "test:start", listener: (data: TestStart) => void): this; on(event: "test:stderr", listener: (data: TestStderr) => void): this; on(event: "test:stdout", listener: (data: TestStdout) => void): this; on(event: string, listener: (...args: any[]) => void): this; once(event: "test:diagnostic", listener: (data: DiagnosticData) => void): this; once(event: "test:fail", listener: (data: TestFail) => void): this; once(event: "test:pass", listener: (data: TestPass) => void): this; once(event: "test:plan", listener: (data: TestPlan) => void): this; once(event: "test:start", listener: (data: TestStart) => void): this; once(event: "test:stderr", listener: (data: TestStderr) => void): this; once(event: "test:stdout", listener: (data: TestStdout) => void): this; once(event: string, listener: (...args: any[]) => void): this; prependListener(event: "test:diagnostic", listener: (data: DiagnosticData) => void): this; prependListener(event: "test:fail", listener: (data: TestFail) => void): this; prependListener(event: "test:pass", listener: (data: TestPass) => void): this; prependListener(event: "test:plan", listener: (data: TestPlan) => void): this; prependListener(event: "test:start", listener: (data: TestStart) => void): this; prependListener(event: "test:stderr", listener: (data: TestStderr) => void): this; prependListener(event: "test:stdout", listener: (data: TestStdout) => void): this; prependListener(event: string, listener: (...args: any[]) => void): this; prependOnceListener(event: "test:diagnostic", listener: (data: DiagnosticData) => void): this; prependOnceListener(event: "test:fail", listener: (data: TestFail) => void): this; prependOnceListener(event: "test:pass", listener: (data: TestPass) => void): this; prependOnceListener(event: "test:plan", listener: (data: TestPlan) => void): this; prependOnceListener(event: "test:start", listener: (data: TestStart) => void): this; prependOnceListener(event: "test:stderr", listener: (data: TestStderr) => void): this; prependOnceListener(event: "test:stdout", listener: (data: TestStdout) => void): this; prependOnceListener(event: string, listener: (...args: any[]) => void): this; } /** * An instance of `TestContext` is passed to each test function in order to * interact with the test runner. However, the `TestContext` constructor is not * exposed as part of the API. * @since v18.0.0, v16.17.0 */ class TestContext { /** * This function is used to create a hook running before subtest of the current test. * @param fn The hook function. If the hook uses callbacks, the callback function is passed as * the second argument. Default: A no-op function. * @param options Configuration options for the hook. * @since v20.1.0 */ before: typeof before; /** * This function is used to create a hook running before each subtest of the current test. * @param fn The hook function. If the hook uses callbacks, the callback function is passed as * the second argument. Default: A no-op function. * @param options Configuration options for the hook. * @since v18.8.0 */ beforeEach: typeof beforeEach; /** * This function is used to create a hook that runs after the current test finishes. * @param fn The hook function. If the hook uses callbacks, the callback function is passed as * the second argument. Default: A no-op function. * @param options Configuration options for the hook. * @since v18.13.0 */ after: typeof after; /** * This function is used to create a hook running after each subtest of the current test. * @param fn The hook function. If the hook uses callbacks, the callback function is passed as * the second argument. Default: A no-op function. * @param options Configuration options for the hook. * @since v18.8.0 */ afterEach: typeof afterEach; /** * This function is used to write diagnostics to the output. Any diagnostic * information is included at the end of the test's results. This function does * not return a value. * * ```js * test('top level test', (t) => { * t.diagnostic('A diagnostic message'); * }); * ``` * @since v18.0.0, v16.17.0 * @param message Message to be reported. */ diagnostic(message: string): void; /** * The name of the test. * @since v18.8.0, v16.18.0 */ readonly name: string; /** * If `shouldRunOnlyTests` is truthy, the test context will only run tests that * have the `only` option set. Otherwise, all tests are run. If Node.js was not * started with the `--test-only` command-line option, this function is a * no-op. * * ```js * test('top level test', (t) => { * // The test context can be set to run subtests with the 'only' option. * t.runOnly(true); * return Promise.all([ * t.test('this subtest is now skipped'), * t.test('this subtest is run', { only: true }), * ]); * }); * ``` * @since v18.0.0, v16.17.0 * @param shouldRunOnlyTests Whether or not to run `only` tests. */ runOnly(shouldRunOnlyTests: boolean): void; /** * ```js * test('top level test', async (t) => { * await fetch('some/uri', { signal: t.signal }); * }); * ``` * @since v18.7.0, v16.17.0 */ readonly signal: AbortSignal; /** * This function causes the test's output to indicate the test as skipped. If`message` is provided, it is included in the output. Calling `skip()` does * not terminate execution of the test function. This function does not return a * value. * * ```js * test('top level test', (t) => { * // Make sure to return here as well if the test contains additional logic. * t.skip('this is skipped'); * }); * ``` * @since v18.0.0, v16.17.0 * @param message Optional skip message. */ skip(message?: string): void; /** * This function adds a `TODO` directive to the test's output. If `message` is * provided, it is included in the output. Calling `todo()` does not terminate * execution of the test function. This function does not return a value. * * ```js * test('top level test', (t) => { * // This test is marked as `TODO` * t.todo('this is a todo'); * }); * ``` * @since v18.0.0, v16.17.0 * @param message Optional `TODO` message. */ todo(message?: string): void; /** * This function is used to create subtests under the current test. This function behaves in * the same fashion as the top level {@link test} function. * @since v18.0.0 * @param name The name of the test, which is displayed when reporting test results. * Default: The `name` property of fn, or `''` if `fn` does not have a name. * @param options Configuration options for the test * @param fn The function under test. This first argument to this function is a * {@link TestContext} object. If the test uses callbacks, the callback function is * passed as the second argument. Default: A no-op function. * @returns A {@link Promise} resolved with `undefined` once the test completes. */ test: typeof test; /** * Each test provides its own MockTracker instance. */ readonly mock: MockTracker; } /** * An instance of `SuiteContext` is passed to each suite function in order to * interact with the test runner. However, the `SuiteContext` constructor is not * exposed as part of the API. * @since v18.7.0, v16.17.0 */ class SuiteContext { /** * The name of the suite. * @since v18.8.0, v16.18.0 */ readonly name: string; /** * Can be used to abort test subtasks when the test has been aborted. * @since v18.7.0, v16.17.0 */ readonly signal: AbortSignal; } interface TestOptions { /** * If a number is provided, then that many tests would run in parallel. * If truthy, it would run (number of cpu cores - 1) tests in parallel. * For subtests, it will be `Infinity` tests in parallel. * If falsy, it would only run one test at a time. * If unspecified, subtests inherit this value from their parent. * @default false */ concurrency?: number | boolean | undefined; /** * If truthy, and the test context is configured to run `only` tests, then this test will be * run. Otherwise, the test is skipped. * @default false */ only?: boolean | undefined; /** * Allows aborting an in-progress test. * @since v18.8.0 */ signal?: AbortSignal | undefined; /** * If truthy, the test is skipped. If a string is provided, that string is displayed in the * test results as the reason for skipping the test. * @default false */ skip?: boolean | string | undefined; /** * A number of milliseconds the test will fail after. If unspecified, subtests inherit this * value from their parent. * @default Infinity * @since v18.7.0 */ timeout?: number | undefined; /** * If truthy, the test marked as `TODO`. If a string is provided, that string is displayed in * the test results as the reason why the test is `TODO`. * @default false */ todo?: boolean | string | undefined; } /** * This function is used to create a hook running before running a suite. * * ```js * describe('tests', async () => { * before(() => console.log('about to run some test')); * it('is a subtest', () => { * assert.ok('some relevant assertion here'); * }); * }); * ``` * @since v18.8.0, v16.18.0 * @param [fn='A no-op function'] The hook function. If the hook uses callbacks, the callback function is passed as the second argument. * @param options Configuration options for the hook. The following properties are supported: */ function before(fn?: HookFn, options?: HookOptions): void; /** * This function is used to create a hook running after running a suite. * * ```js * describe('tests', async () => { * after(() => console.log('finished running tests')); * it('is a subtest', () => { * assert.ok('some relevant assertion here'); * }); * }); * ``` * @since v18.8.0, v16.18.0 * @param [fn='A no-op function'] The hook function. If the hook uses callbacks, the callback function is passed as the second argument. * @param options Configuration options for the hook. The following properties are supported: */ function after(fn?: HookFn, options?: HookOptions): void; /** * This function is used to create a hook running * before each subtest of the current suite. * * ```js * describe('tests', async () => { * beforeEach(() => console.log('about to run a test')); * it('is a subtest', () => { * assert.ok('some relevant assertion here'); * }); * }); * ``` * @since v18.8.0, v16.18.0 * @param [fn='A no-op function'] The hook function. If the hook uses callbacks, the callback function is passed as the second argument. * @param options Configuration options for the hook. The following properties are supported: */ function beforeEach(fn?: HookFn, options?: HookOptions): void; /** * This function is used to create a hook running * after each subtest of the current test. * * ```js * describe('tests', async () => { * afterEach(() => console.log('finished running a test')); * it('is a subtest', () => { * assert.ok('some relevant assertion here'); * }); * }); * ``` * @since v18.8.0, v16.18.0 * @param [fn='A no-op function'] The hook function. If the hook uses callbacks, the callback function is passed as the second argument. * @param options Configuration options for the hook. The following properties are supported: */ function afterEach(fn?: HookFn, options?: HookOptions): void; /** * The hook function. If the hook uses callbacks, the callback function is passed as the * second argument. */ type HookFn = (s: SuiteContext, done: (result?: any) => void) => any; /** * Configuration options for hooks. * @since v18.8.0 */ interface HookOptions { /** * Allows aborting an in-progress hook. */ signal?: AbortSignal | undefined; /** * A number of milliseconds the hook will fail after. If unspecified, subtests inherit this * value from their parent. * @default Infinity */ timeout?: number | undefined; } interface MockFunctionOptions { /** * The number of times that the mock will use the behavior of `implementation`. * Once the mock function has been called `times` times, * it will automatically restore the behavior of `original`. * This value must be an integer greater than zero. * @default Infinity */ times?: number | undefined; } interface MockMethodOptions extends MockFunctionOptions { /** * If `true`, `object[methodName]` is treated as a getter. * This option cannot be used with the `setter` option. */ getter?: boolean | undefined; /** * If `true`, `object[methodName]` is treated as a setter. * This option cannot be used with the `getter` option. */ setter?: boolean | undefined; } type Mock = F & { mock: MockFunctionContext; }; type NoOpFunction = (...args: any[]) => undefined; type FunctionPropertyNames = { [K in keyof T]: T[K] extends Function ? K : never; }[keyof T]; /** * The `MockTracker` class is used to manage mocking functionality. The test runner * module provides a top level `mock` export which is a `MockTracker` instance. * Each test also provides its own `MockTracker` instance via the test context's`mock` property. * @since v19.1.0, v18.13.0 */ class MockTracker { /** * This function is used to create a mock function. * * The following example creates a mock function that increments a counter by one * on each invocation. The `times` option is used to modify the mock behavior such * that the first two invocations add two to the counter instead of one. * * ```js * test('mocks a counting function', (t) => { * let cnt = 0; * * function addOne() { * cnt++; * return cnt; * } * * function addTwo() { * cnt += 2; * return cnt; * } * * const fn = t.mock.fn(addOne, addTwo, { times: 2 }); * * assert.strictEqual(fn(), 2); * assert.strictEqual(fn(), 4); * assert.strictEqual(fn(), 5); * assert.strictEqual(fn(), 6); * }); * ``` * @since v19.1.0, v18.13.0 * @param [original='A no-op function'] An optional function to create a mock on. * @param implementation An optional function used as the mock implementation for `original`. This is useful for creating mocks that exhibit one behavior for a specified number of calls and * then restore the behavior of `original`. * @param options Optional configuration options for the mock function. The following properties are supported: * @return The mocked function. The mocked function contains a special `mock` property, which is an instance of {@link MockFunctionContext}, and can be used for inspecting and changing the * behavior of the mocked function. */ fn(original?: F, options?: MockFunctionOptions): Mock; fn( original?: F, implementation?: Implementation, options?: MockFunctionOptions, ): Mock; /** * This function is used to create a mock on an existing object method. The * following example demonstrates how a mock is created on an existing object * method. * * ```js * test('spies on an object method', (t) => { * const number = { * value: 5, * subtract(a) { * return this.value - a; * }, * }; * * t.mock.method(number, 'subtract'); * assert.strictEqual(number.subtract.mock.calls.length, 0); * assert.strictEqual(number.subtract(3), 2); * assert.strictEqual(number.subtract.mock.calls.length, 1); * * const call = number.subtract.mock.calls[0]; * * assert.deepStrictEqual(call.arguments, [3]); * assert.strictEqual(call.result, 2); * assert.strictEqual(call.error, undefined); * assert.strictEqual(call.target, undefined); * assert.strictEqual(call.this, number); * }); * ``` * @since v19.1.0, v18.13.0 * @param object The object whose method is being mocked. * @param methodName The identifier of the method on `object` to mock. If `object[methodName]` is not a function, an error is thrown. * @param implementation An optional function used as the mock implementation for `object[methodName]`. * @param options Optional configuration options for the mock method. The following properties are supported: * @return The mocked method. The mocked method contains a special `mock` property, which is an instance of {@link MockFunctionContext}, and can be used for inspecting and changing the * behavior of the mocked method. */ method< MockedObject extends object, MethodName extends FunctionPropertyNames, >( object: MockedObject, methodName: MethodName, options?: MockFunctionOptions, ): MockedObject[MethodName] extends Function ? Mock : never; method< MockedObject extends object, MethodName extends FunctionPropertyNames, Implementation extends Function, >( object: MockedObject, methodName: MethodName, implementation: Implementation, options?: MockFunctionOptions, ): MockedObject[MethodName] extends Function ? Mock : never; method( object: MockedObject, methodName: keyof MockedObject, options: MockMethodOptions, ): Mock; method( object: MockedObject, methodName: keyof MockedObject, implementation: Function, options: MockMethodOptions, ): Mock; /** * This function is syntax sugar for `MockTracker.method` with `options.getter`set to `true`. * @since v19.3.0, v18.13.0 */ getter< MockedObject extends object, MethodName extends keyof MockedObject, >( object: MockedObject, methodName: MethodName, options?: MockFunctionOptions, ): Mock<() => MockedObject[MethodName]>; getter< MockedObject extends object, MethodName extends keyof MockedObject, Implementation extends Function, >( object: MockedObject, methodName: MethodName, implementation?: Implementation, options?: MockFunctionOptions, ): Mock<(() => MockedObject[MethodName]) | Implementation>; /** * This function is syntax sugar for `MockTracker.method` with `options.setter`set to `true`. * @since v19.3.0, v18.13.0 */ setter< MockedObject extends object, MethodName extends keyof MockedObject, >( object: MockedObject, methodName: MethodName, options?: MockFunctionOptions, ): Mock<(value: MockedObject[MethodName]) => void>; setter< MockedObject extends object, MethodName extends keyof MockedObject, Implementation extends Function, >( object: MockedObject, methodName: MethodName, implementation?: Implementation, options?: MockFunctionOptions, ): Mock<((value: MockedObject[MethodName]) => void) | Implementation>; /** * This function restores the default behavior of all mocks that were previously * created by this `MockTracker` and disassociates the mocks from the`MockTracker` instance. Once disassociated, the mocks can still be used, but the`MockTracker` instance can no longer be * used to reset their behavior or * otherwise interact with them. * * After each test completes, this function is called on the test context's`MockTracker`. If the global `MockTracker` is used extensively, calling this * function manually is recommended. * @since v19.1.0, v18.13.0 */ reset(): void; /** * This function restores the default behavior of all mocks that were previously * created by this `MockTracker`. Unlike `mock.reset()`, `mock.restoreAll()` does * not disassociate the mocks from the `MockTracker` instance. * @since v19.1.0, v18.13.0 */ restoreAll(): void; timers: MockTimers; } const mock: MockTracker; interface MockFunctionCall< F extends Function, ReturnType = F extends (...args: any) => infer T ? T : F extends abstract new(...args: any) => infer T ? T : unknown, Args = F extends (...args: infer Y) => any ? Y : F extends abstract new(...args: infer Y) => any ? Y : unknown[], > { /** * An array of the arguments passed to the mock function. */ arguments: Args; /** * If the mocked function threw then this property contains the thrown value. */ error: unknown | undefined; /** * The value returned by the mocked function. * * If the mocked function threw, it will be `undefined`. */ result: ReturnType | undefined; /** * An `Error` object whose stack can be used to determine the callsite of the mocked function invocation. */ stack: Error; /** * If the mocked function is a constructor, this field contains the class being constructed. * Otherwise this will be `undefined`. */ target: F extends abstract new(...args: any) => any ? F : undefined; /** * The mocked function's `this` value. */ this: unknown; } /** * The `MockFunctionContext` class is used to inspect or manipulate the behavior of * mocks created via the `MockTracker` APIs. * @since v19.1.0, v18.13.0 */ class MockFunctionContext { /** * A getter that returns a copy of the internal array used to track calls to the * mock. Each entry in the array is an object with the following properties. * @since v19.1.0, v18.13.0 */ readonly calls: Array>; /** * This function returns the number of times that this mock has been invoked. This * function is more efficient than checking `ctx.calls.length` because `ctx.calls`is a getter that creates a copy of the internal call tracking array. * @since v19.1.0, v18.13.0 * @return The number of times that this mock has been invoked. */ callCount(): number; /** * This function is used to change the behavior of an existing mock. * * The following example creates a mock function using `t.mock.fn()`, calls the * mock function, and then changes the mock implementation to a different function. * * ```js * test('changes a mock behavior', (t) => { * let cnt = 0; * * function addOne() { * cnt++; * return cnt; * } * * function addTwo() { * cnt += 2; * return cnt; * } * * const fn = t.mock.fn(addOne); * * assert.strictEqual(fn(), 1); * fn.mock.mockImplementation(addTwo); * assert.strictEqual(fn(), 3); * assert.strictEqual(fn(), 5); * }); * ``` * @since v19.1.0, v18.13.0 * @param implementation The function to be used as the mock's new implementation. */ mockImplementation(implementation: Function): void; /** * This function is used to change the behavior of an existing mock for a single * invocation. Once invocation `onCall` has occurred, the mock will revert to * whatever behavior it would have used had `mockImplementationOnce()` not been * called. * * The following example creates a mock function using `t.mock.fn()`, calls the * mock function, changes the mock implementation to a different function for the * next invocation, and then resumes its previous behavior. * * ```js * test('changes a mock behavior once', (t) => { * let cnt = 0; * * function addOne() { * cnt++; * return cnt; * } * * function addTwo() { * cnt += 2; * return cnt; * } * * const fn = t.mock.fn(addOne); * * assert.strictEqual(fn(), 1); * fn.mock.mockImplementationOnce(addTwo); * assert.strictEqual(fn(), 3); * assert.strictEqual(fn(), 4); * }); * ``` * @since v19.1.0, v18.13.0 * @param implementation The function to be used as the mock's implementation for the invocation number specified by `onCall`. * @param onCall The invocation number that will use `implementation`. If the specified invocation has already occurred then an exception is thrown. */ mockImplementationOnce(implementation: Function, onCall?: number): void; /** * Resets the call history of the mock function. * @since v19.3.0, v18.13.0 */ resetCalls(): void; /** * Resets the implementation of the mock function to its original behavior. The * mock can still be used after calling this function. * @since v19.1.0, v18.13.0 */ restore(): void; } type Timer = "setInterval" | "setTimeout" | "setImmediate" | "Date"; interface MockTimersOptions { apis: Timer[]; now?: number | Date; } /** * Mocking timers is a technique commonly used in software testing to simulate and * control the behavior of timers, such as `setInterval` and `setTimeout`, * without actually waiting for the specified time intervals. * * The MockTimers API also allows for mocking of the `Date` constructor and * `setImmediate`/`clearImmediate` functions. * * The `MockTracker` provides a top-level `timers` export * which is a `MockTimers` instance. * @since v20.4.0 * @experimental */ class MockTimers { /** * Enables timer mocking for the specified timers. * * **Note:** When you enable mocking for a specific timer, its associated * clear function will also be implicitly mocked. * * **Note:** Mocking `Date` will affect the behavior of the mocked timers * as they use the same internal clock. * * Example usage without setting initial time: * * ```js * import { mock } from 'node:test'; * mock.timers.enable({ apis: ['setInterval', 'Date'], now: 1234 }); * ``` * * The above example enables mocking for the `Date` constructor, `setInterval` timer and * implicitly mocks the `clearInterval` function. Only the `Date` constructor from `globalThis`, * `setInterval` and `clearInterval` functions from `node:timers`,`node:timers/promises`, and `globalThis` will be mocked. * * Example usage with initial time set * * ```js * import { mock } from 'node:test'; * mock.timers.enable({ apis: ['Date'], now: 1000 }); * ``` * * Example usage with initial Date object as time set * * ```js * import { mock } from 'node:test'; * mock.timers.enable({ apis: ['Date'], now: new Date() }); * ``` * * Alternatively, if you call `mock.timers.enable()` without any parameters: * * All timers (`'setInterval'`, `'clearInterval'`, `'Date'`, `'setImmediate'`, `'clearImmediate'`, `'setTimeout'`, and `'clearTimeout'`) * will be mocked. * * The `setInterval`, `clearInterval`, `setTimeout`, and `clearTimeout` functions from `node:timers`, `node:timers/promises`, * and `globalThis` will be mocked. * The `Date` constructor from `globalThis` will be mocked. * * If there is no initial epoch set, the initial date will be based on 0 in the Unix epoch. This is `January 1st, 1970, 00:00:00 UTC`. You can set an initial date by passing a now property to the `.enable()` method. This value will be used as the initial date for the mocked Date object. It can either be a positive integer, or another Date object. * @since v20.4.0 */ enable(options?: MockTimersOptions): void; /** * You can use the `.setTime()` method to manually move the mocked date to another time. This method only accepts a positive integer. * Note: This method will execute any mocked timers that are in the past from the new time. * In the below example we are setting a new time for the mocked date. * ```js * import assert from 'node:assert'; * import { test } from 'node:test'; * test('sets the time of a date object', (context) => { * // Optionally choose what to mock * context.mock.timers.enable({ apis: ['Date'], now: 100 }); * assert.strictEqual(Date.now(), 100); * // Advance in time will also advance the date * context.mock.timers.setTime(1000); * context.mock.timers.tick(200); * assert.strictEqual(Date.now(), 1200); * }); * ``` */ setTime(time: number): void; /** * This function restores the default behavior of all mocks that were previously * created by this `MockTimers` instance and disassociates the mocks * from the `MockTracker` instance. * * **Note:** After each test completes, this function is called on * the test context's `MockTracker`. * * ```js * import { mock } from 'node:test'; * mock.timers.reset(); * ``` * @since v20.4.0 */ reset(): void; /** * Advances time for all mocked timers. * * **Note:** This diverges from how `setTimeout` in Node.js behaves and accepts * only positive numbers. In Node.js, `setTimeout` with negative numbers is * only supported for web compatibility reasons. * * The following example mocks a `setTimeout` function and * by using `.tick` advances in * time triggering all pending timers. * * ```js * import assert from 'node:assert'; * import { test } from 'node:test'; * * test('mocks setTimeout to be executed synchronously without having to actually wait for it', (context) => { * const fn = context.mock.fn(); * * context.mock.timers.enable({ apis: ['setTimeout'] }); * * setTimeout(fn, 9999); * * assert.strictEqual(fn.mock.callCount(), 0); * * // Advance in time * context.mock.timers.tick(9999); * * assert.strictEqual(fn.mock.callCount(), 1); * }); * ``` * * Alternativelly, the `.tick` function can be called many times * * ```js * import assert from 'node:assert'; * import { test } from 'node:test'; * * test('mocks setTimeout to be executed synchronously without having to actually wait for it', (context) => { * const fn = context.mock.fn(); * context.mock.timers.enable({ apis: ['setTimeout'] }); * const nineSecs = 9000; * setTimeout(fn, nineSecs); * * const twoSeconds = 3000; * context.mock.timers.tick(twoSeconds); * context.mock.timers.tick(twoSeconds); * context.mock.timers.tick(twoSeconds); * * assert.strictEqual(fn.mock.callCount(), 1); * }); * ``` * * Advancing time using `.tick` will also advance the time for any `Date` object * created after the mock was enabled (if `Date` was also set to be mocked). * * ```js * import assert from 'node:assert'; * import { test } from 'node:test'; * * test('mocks setTimeout to be executed synchronously without having to actually wait for it', (context) => { * const fn = context.mock.fn(); * * context.mock.timers.enable({ apis: ['setTimeout', 'Date'] }); * setTimeout(fn, 9999); * * assert.strictEqual(fn.mock.callCount(), 0); * assert.strictEqual(Date.now(), 0); * * // Advance in time * context.mock.timers.tick(9999); * assert.strictEqual(fn.mock.callCount(), 1); * assert.strictEqual(Date.now(), 9999); * }); * ``` * @since v20.4.0 */ tick(milliseconds: number): void; /** * Triggers all pending mocked timers immediately. If the `Date` object is also * mocked, it will also advance the `Date` object to the furthest timer's time. * * The example below triggers all pending timers immediately, * causing them to execute without any delay. * * ```js * import assert from 'node:assert'; * import { test } from 'node:test'; * * test('runAll functions following the given order', (context) => { * context.mock.timers.enable({ apis: ['setTimeout', 'Date'] }); * const results = []; * setTimeout(() => results.push(1), 9999); * * // Notice that if both timers have the same timeout, * // the order of execution is guaranteed * setTimeout(() => results.push(3), 8888); * setTimeout(() => results.push(2), 8888); * * assert.deepStrictEqual(results, []); * * context.mock.timers.runAll(); * assert.deepStrictEqual(results, [3, 2, 1]); * // The Date object is also advanced to the furthest timer's time * assert.strictEqual(Date.now(), 9999); * }); * ``` * * **Note:** The `runAll()` function is specifically designed for * triggering timers in the context of timer mocking. * It does not have any effect on real-time system * clocks or actual timers outside of the mocking environment. * @since v20.4.0 */ runAll(): void; /** * Calls {@link MockTimers.reset()}. */ [Symbol.dispose](): void; } export { after, afterEach, before, beforeEach, describe, it, Mock, mock, only, run, skip, test, test as default, todo, }; } interface TestLocationInfo { /** * The column number where the test is defined, or * `undefined` if the test was run through the REPL. */ column?: number; /** * The path of the test file, `undefined` if test is not ran through a file. */ file?: string; /** * The line number where the test is defined, or * `undefined` if the test was run through the REPL. */ line?: number; } interface DiagnosticData extends TestLocationInfo { /** * The diagnostic message. */ message: string; /** * The nesting level of the test. */ nesting: number; } interface TestFail extends TestLocationInfo { /** * Additional execution metadata. */ details: { /** * The duration of the test in milliseconds. */ duration_ms: number; /** * The error thrown by the test. */ error: Error; /** * The type of the test, used to denote whether this is a suite. * @since 20.0.0, 19.9.0, 18.17.0 */ type?: "suite"; }; /** * The test name. */ name: string; /** * The nesting level of the test. */ nesting: number; /** * The ordinal number of the test. */ testNumber: number; /** * Present if `context.todo` is called. */ todo?: string | boolean; /** * Present if `context.skip` is called. */ skip?: string | boolean; } interface TestPass extends TestLocationInfo { /** * Additional execution metadata. */ details: { /** * The duration of the test in milliseconds. */ duration_ms: number; /** * The type of the test, used to denote whether this is a suite. * @since 20.0.0, 19.9.0, 18.17.0 */ type?: "suite"; }; /** * The test name. */ name: string; /** * The nesting level of the test. */ nesting: number; /** * The ordinal number of the test. */ testNumber: number; /** * Present if `context.todo` is called. */ todo?: string | boolean; /** * Present if `context.skip` is called. */ skip?: string | boolean; } interface TestPlan extends TestLocationInfo { /** * The nesting level of the test. */ nesting: number; /** * The number of subtests that have ran. */ count: number; } interface TestStart extends TestLocationInfo { /** * The test name. */ name: string; /** * The nesting level of the test. */ nesting: number; } interface TestStderr extends TestLocationInfo { /** * The message written to `stderr` */ message: string; } interface TestStdout extends TestLocationInfo { /** * The message written to `stdout` */ message: string; } interface TestEnqueue extends TestLocationInfo { /** * The test name */ name: string; /** * The nesting level of the test. */ nesting: number; } interface TestDequeue extends TestLocationInfo { /** * The test name */ name: string; /** * The nesting level of the test. */ nesting: number; } /** * The `node:test/reporters` module exposes the builtin-reporters for `node:test`. * To access it: * * ```js * import test from 'node:test/reporters'; * ``` * * This module is only available under the `node:` scheme. The following will not * work: * * ```js * import test from 'test/reporters'; * ``` * @since v19.9.0 * @see [source](https://github.com/nodejs/node/blob/v20.2.0/lib/test/reporters.js) */ declare module "node:test/reporters" { import { Transform, TransformOptions } from "node:stream"; type TestEvent = | { type: "test:diagnostic"; data: DiagnosticData } | { type: "test:fail"; data: TestFail } | { type: "test:pass"; data: TestPass } | { type: "test:plan"; data: TestPlan } | { type: "test:start"; data: TestStart } | { type: "test:stderr"; data: TestStderr } | { type: "test:stdout"; data: TestStdout } | { type: "test:enqueue"; data: TestEnqueue } | { type: "test:dequeue"; data: TestDequeue } | { type: "test:watch:drained" }; type TestEventGenerator = AsyncGenerator; /** * The `dot` reporter outputs the test results in a compact format, * where each passing test is represented by a `.`, * and each failing test is represented by a `X`. */ function dot(source: TestEventGenerator): AsyncGenerator<"\n" | "." | "X", void>; /** * The `tap` reporter outputs the test results in the [TAP](https://testanything.org/) format. */ function tap(source: TestEventGenerator): AsyncGenerator; /** * The `spec` reporter outputs the test results in a human-readable format. */ class Spec extends Transform { constructor(); } /** * The `junit` reporter outputs test results in a jUnit XML format */ function junit(source: TestEventGenerator): AsyncGenerator; class Lcov extends Transform { constructor(opts?: TransformOptions); } export { dot, junit, Lcov as lcov, Spec as spec, tap, TestEvent }; }