File: /var/dev/math/ui/node_modules/@types/node/test.d.ts
/**
* 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 'node: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/v24.x/lib/test.js)
*/
declare module "node:test" {
import { Readable } from "node:stream";
import TestFn = test.TestFn;
import TestOptions = test.TestOptions;
/**
* 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 suite, 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 of the test, which is displayed when reporting test results.
* Defaults to the `name` property of `fn`, or `'<anonymous>'` if `fn` does not have a name.
* @param options Configuration options for the test.
* @param fn 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 a suite.
*/
function test(name?: string, fn?: TestFn): Promise<void>;
function test(name?: string, options?: TestOptions, fn?: TestFn): Promise<void>;
function test(options?: TestOptions, fn?: TestFn): Promise<void>;
function test(fn?: TestFn): Promise<void>;
namespace test {
export { test };
export { suite as describe, test as it };
}
namespace test {
/**
* **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.
*/
function run(options?: RunOptions): TestsStream;
/**
* The `suite()` function is imported from the `node:test` module.
* @param name The name of the suite, which is displayed when reporting test results.
* Defaults to the `name` property of `fn`, or `'<anonymous>'` if `fn` does not have a name.
* @param options Configuration options for the suite. This supports the same options as {@link test}.
* @param fn The suite function declaring nested tests and suites. The first argument to this function is a {@link SuiteContext} object.
* @return Immediately fulfilled with `undefined`.
* @since v20.13.0
*/
function suite(name?: string, options?: TestOptions, fn?: SuiteFn): Promise<void>;
function suite(name?: string, fn?: SuiteFn): Promise<void>;
function suite(options?: TestOptions, fn?: SuiteFn): Promise<void>;
function suite(fn?: SuiteFn): Promise<void>;
namespace suite {
/**
* Shorthand for skipping a suite. This is the same as calling {@link suite} with `options.skip` set to `true`.
* @since v20.13.0
*/
function skip(name?: string, options?: TestOptions, fn?: SuiteFn): Promise<void>;
function skip(name?: string, fn?: SuiteFn): Promise<void>;
function skip(options?: TestOptions, fn?: SuiteFn): Promise<void>;
function skip(fn?: SuiteFn): Promise<void>;
/**
* Shorthand for marking a suite as `TODO`. This is the same as calling {@link suite} with `options.todo` set to `true`.
* @since v20.13.0
*/
function todo(name?: string, options?: TestOptions, fn?: SuiteFn): Promise<void>;
function todo(name?: string, fn?: SuiteFn): Promise<void>;
function todo(options?: TestOptions, fn?: SuiteFn): Promise<void>;
function todo(fn?: SuiteFn): Promise<void>;
/**
* Shorthand for marking a suite as `only`. This is the same as calling {@link suite} with `options.only` set to `true`.
* @since v20.13.0
*/
function only(name?: string, options?: TestOptions, fn?: SuiteFn): Promise<void>;
function only(name?: string, fn?: SuiteFn): Promise<void>;
function only(options?: TestOptions, fn?: SuiteFn): Promise<void>;
function only(fn?: SuiteFn): Promise<void>;
}
/**
* Shorthand for skipping a test. This is the same as calling {@link test} with `options.skip` set to `true`.
* @since v20.2.0
*/
function skip(name?: string, options?: TestOptions, fn?: TestFn): Promise<void>;
function skip(name?: string, fn?: TestFn): Promise<void>;
function skip(options?: TestOptions, fn?: TestFn): Promise<void>;
function skip(fn?: TestFn): Promise<void>;
/**
* Shorthand for marking a test as `TODO`. This is the same as calling {@link test} with `options.todo` set to `true`.
* @since v20.2.0
*/
function todo(name?: string, options?: TestOptions, fn?: TestFn): Promise<void>;
function todo(name?: string, fn?: TestFn): Promise<void>;
function todo(options?: TestOptions, fn?: TestFn): Promise<void>;
function todo(fn?: TestFn): Promise<void>;
/**
* Shorthand for marking a test as `only`. This is the same as calling {@link test} with `options.only` set to `true`.
* @since v20.2.0
*/
function only(name?: string, options?: TestOptions, fn?: TestFn): Promise<void>;
function only(name?: string, fn?: TestFn): Promise<void>;
function only(options?: TestOptions, fn?: TestFn): Promise<void>;
function only(fn?: TestFn): Promise<void>;
/**
* The type of a function passed to {@link 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<void>;
/**
* The type of a suite test function. The argument to this function is a {@link SuiteContext} object.
*/
type SuiteFn = (s: SuiteContext) => void | Promise<void>;
interface TestShard {
/**
* A positive integer between 1 and `total` 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 test processes would run in parallel, where each process corresponds to one test file.
* If `true`, it would run `os.availableParallelism() - 1` test files in parallel. If `false`, it would only run one test file at a time.
* @default false
*/
concurrency?: number | boolean | undefined;
/**
* Specifies the current working directory to be used by the test runner.
* Serves as the base path for resolving files according to the
* [test runner execution model](https://nodejs.org/docs/latest-v24.x/api/test.html#test-runner-execution-model).
* @since v23.0.0
* @default process.cwd()
*/
cwd?: string | undefined;
/**
* An array containing the list of files to run. If omitted, files are run according to the
* [test runner execution model](https://nodejs.org/docs/latest-v24.x/api/test.html#test-runner-execution-model).
*/
files?: readonly string[] | undefined;
/**
* Configures the test runner to exit the process once all known
* tests have finished executing even if the event loop would
* otherwise remain active.
* @default false
*/
forceExit?: boolean | undefined;
/**
* An array containing the list of glob patterns to match test files.
* This option cannot be used together with `files`. If omitted, files are run according to the
* [test runner execution model](https://nodejs.org/docs/latest-v24.x/api/test.html#test-runner-execution-model).
* @since v22.6.0
*/
globPatterns?: readonly string[] | undefined;
/**
* Sets inspector port of test child process.
* This can be a number, or a function that takes no arguments and returns a
* number. If a nullish value is provided, each process gets its own port,
* incremented from the primary's `process.debugPort`. This option is ignored
* if the `isolation` option is set to `'none'` as no child processes are
* spawned.
* @default undefined
*/
inspectPort?: number | (() => number) | undefined;
/**
* Configures the type of test isolation. If set to
* `'process'`, each test file is run in a separate child process. If set to
* `'none'`, all test files run in the current process.
* @default 'process'
* @since v22.8.0
*/
isolation?: "process" | "none" | undefined;
/**
* If truthy, the test context will only run tests that have the `only` option set
*/
only?: boolean | undefined;
/**
* A function that accepts the `TestsStream` instance and can be used to setup listeners before any tests are run.
* @default undefined
*/
setup?: ((reporter: TestsStream) => void | Promise<void>) | undefined;
/**
* An array of CLI flags to pass to the `node` executable when
* spawning the subprocesses. This option has no effect when `isolation` is `'none`'.
* @since v22.10.0
* @default []
*/
execArgv?: readonly string[] | undefined;
/**
* An array of CLI flags to pass to each test file when spawning the
* subprocesses. This option has no effect when `isolation` is `'none'`.
* @since v22.10.0
* @default []
*/
argv?: readonly string[] | undefined;
/**
* Allows aborting an in-progress test execution.
*/
signal?: AbortSignal | undefined;
/**
* If provided, only run tests whose name matches the provided pattern.
* Strings are interpreted as JavaScript regular expressions.
* @default undefined
*/
testNamePatterns?: string | RegExp | ReadonlyArray<string | RegExp> | undefined;
/**
* A String, RegExp or a RegExp Array, that can be used to exclude running 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.
* @default undefined
* @since v22.1.0
*/
testSkipPatterns?: string | RegExp | ReadonlyArray<string | RegExp> | undefined;
/**
* The number of milliseconds after which the test execution will fail.
* If unspecified, subtests inherit this value from their parent.
* @default Infinity
*/
timeout?: number | undefined;
/**
* Whether to run in watch mode or not.
* @default false
*/
watch?: boolean | undefined;
/**
* Running tests in a specific shard.
* @default undefined
*/
shard?: TestShard | undefined;
/**
* enable [code coverage](https://nodejs.org/docs/latest-v24.x/api/test.html#collecting-code-coverage) collection.
* @since v22.10.0
* @default false
*/
coverage?: boolean | undefined;
/**
* Excludes specific files from code coverage
* using a glob pattern, which can match both absolute and relative file paths.
* This property is only applicable when `coverage` was set to `true`.
* If both `coverageExcludeGlobs` and `coverageIncludeGlobs` are provided,
* files must meet **both** criteria to be included in the coverage report.
* @since v22.10.0
* @default undefined
*/
coverageExcludeGlobs?: string | readonly string[] | undefined;
/**
* Includes specific files in code coverage
* using a glob pattern, which can match both absolute and relative file paths.
* This property is only applicable when `coverage` was set to `true`.
* If both `coverageExcludeGlobs` and `coverageIncludeGlobs` are provided,
* files must meet **both** criteria to be included in the coverage report.
* @since v22.10.0
* @default undefined
*/
coverageIncludeGlobs?: string | readonly string[] | undefined;
/**
* Require a minimum percent of covered lines. If code
* coverage does not reach the threshold specified, the process will exit with code `1`.
* @since v22.10.0
* @default 0
*/
lineCoverage?: number | undefined;
/**
* Require a minimum percent of covered branches. If code
* coverage does not reach the threshold specified, the process will exit with code `1`.
* @since v22.10.0
* @default 0
*/
branchCoverage?: number | undefined;
/**
* Require a minimum percent of covered functions. If code
* coverage does not reach the threshold specified, the process will exit with code `1`.
* @since v22.10.0
* @default 0
*/
functionCoverage?: number | undefined;
}
/**
* A successful call to `run()` will return a new `TestsStream` object, streaming a series of events representing the execution of the tests.
*
* Some of the events are guaranteed to be emitted in the same order as the tests are defined, while others are emitted in the order that the tests execute.
* @since v18.9.0, v16.19.0
*/
interface TestsStream extends Readable {
addListener(event: "test:coverage", listener: (data: EventData.TestCoverage) => void): this;
addListener(event: "test:complete", listener: (data: EventData.TestComplete) => void): this;
addListener(event: "test:dequeue", listener: (data: EventData.TestDequeue) => void): this;
addListener(event: "test:diagnostic", listener: (data: EventData.TestDiagnostic) => void): this;
addListener(event: "test:enqueue", listener: (data: EventData.TestEnqueue) => void): this;
addListener(event: "test:fail", listener: (data: EventData.TestFail) => void): this;
addListener(event: "test:pass", listener: (data: EventData.TestPass) => void): this;
addListener(event: "test:plan", listener: (data: EventData.TestPlan) => void): this;
addListener(event: "test:start", listener: (data: EventData.TestStart) => void): this;
addListener(event: "test:stderr", listener: (data: EventData.TestStderr) => void): this;
addListener(event: "test:stdout", listener: (data: EventData.TestStdout) => void): this;
addListener(event: "test:summary", listener: (data: EventData.TestSummary) => void): this;
addListener(event: "test:watch:drained", listener: () => void): this;
addListener(event: string, listener: (...args: any[]) => void): this;
emit(event: "test:coverage", data: EventData.TestCoverage): boolean;
emit(event: "test:complete", data: EventData.TestComplete): boolean;
emit(event: "test:dequeue", data: EventData.TestDequeue): boolean;
emit(event: "test:diagnostic", data: EventData.TestDiagnostic): boolean;
emit(event: "test:enqueue", data: EventData.TestEnqueue): boolean;
emit(event: "test:fail", data: EventData.TestFail): boolean;
emit(event: "test:pass", data: EventData.TestPass): boolean;
emit(event: "test:plan", data: EventData.TestPlan): boolean;
emit(event: "test:start", data: EventData.TestStart): boolean;
emit(event: "test:stderr", data: EventData.TestStderr): boolean;
emit(event: "test:stdout", data: EventData.TestStdout): boolean;
emit(event: "test:summary", data: EventData.TestSummary): boolean;
emit(event: "test:watch:drained"): boolean;
emit(event: string | symbol, ...args: any[]): boolean;
on(event: "test:coverage", listener: (data: EventData.TestCoverage) => void): this;
on(event: "test:complete", listener: (data: EventData.TestComplete) => void): this;
on(event: "test:dequeue", listener: (data: EventData.TestDequeue) => void): this;
on(event: "test:diagnostic", listener: (data: EventData.TestDiagnostic) => void): this;
on(event: "test:enqueue", listener: (data: EventData.TestEnqueue) => void): this;
on(event: "test:fail", listener: (data: EventData.TestFail) => void): this;
on(event: "test:pass", listener: (data: EventData.TestPass) => void): this;
on(event: "test:plan", listener: (data: EventData.TestPlan) => void): this;
on(event: "test:start", listener: (data: EventData.TestStart) => void): this;
on(event: "test:stderr", listener: (data: EventData.TestStderr) => void): this;
on(event: "test:stdout", listener: (data: EventData.TestStdout) => void): this;
on(event: "test:summary", listener: (data: EventData.TestSummary) => void): this;
on(event: "test:watch:drained", listener: () => void): this;
on(event: string, listener: (...args: any[]) => void): this;
once(event: "test:coverage", listener: (data: EventData.TestCoverage) => void): this;
once(event: "test:complete", listener: (data: EventData.TestComplete) => void): this;
once(event: "test:dequeue", listener: (data: EventData.TestDequeue) => void): this;
once(event: "test:diagnostic", listener: (data: EventData.TestDiagnostic) => void): this;
once(event: "test:enqueue", listener: (data: EventData.TestEnqueue) => void): this;
once(event: "test:fail", listener: (data: EventData.TestFail) => void): this;
once(event: "test:pass", listener: (data: EventData.TestPass) => void): this;
once(event: "test:plan", listener: (data: EventData.TestPlan) => void): this;
once(event: "test:start", listener: (data: EventData.TestStart) => void): this;
once(event: "test:stderr", listener: (data: EventData.TestStderr) => void): this;
once(event: "test:stdout", listener: (data: EventData.TestStdout) => void): this;
once(event: "test:summary", listener: (data: EventData.TestSummary) => void): this;
once(event: "test:watch:drained", listener: () => void): this;
once(event: string, listener: (...args: any[]) => void): this;
prependListener(event: "test:coverage", listener: (data: EventData.TestCoverage) => void): this;
prependListener(event: "test:complete", listener: (data: EventData.TestComplete) => void): this;
prependListener(event: "test:dequeue", listener: (data: EventData.TestDequeue) => void): this;
prependListener(event: "test:diagnostic", listener: (data: EventData.TestDiagnostic) => void): this;
prependListener(event: "test:enqueue", listener: (data: EventData.TestEnqueue) => void): this;
prependListener(event: "test:fail", listener: (data: EventData.TestFail) => void): this;
prependListener(event: "test:pass", listener: (data: EventData.TestPass) => void): this;
prependListener(event: "test:plan", listener: (data: EventData.TestPlan) => void): this;
prependListener(event: "test:start", listener: (data: EventData.TestStart) => void): this;
prependListener(event: "test:stderr", listener: (data: EventData.TestStderr) => void): this;
prependListener(event: "test:stdout", listener: (data: EventData.TestStdout) => void): this;
prependListener(event: "test:summary", listener: (data: EventData.TestSummary) => void): this;
prependListener(event: "test:watch:drained", listener: () => void): this;
prependListener(event: string, listener: (...args: any[]) => void): this;
prependOnceListener(event: "test:coverage", listener: (data: EventData.TestCoverage) => void): this;
prependOnceListener(event: "test:complete", listener: (data: EventData.TestComplete) => void): this;
prependOnceListener(event: "test:dequeue", listener: (data: EventData.TestDequeue) => void): this;
prependOnceListener(event: "test:diagnostic", listener: (data: EventData.TestDiagnostic) => void): this;
prependOnceListener(event: "test:enqueue", listener: (data: EventData.TestEnqueue) => void): this;
prependOnceListener(event: "test:fail", listener: (data: EventData.TestFail) => void): this;
prependOnceListener(event: "test:pass", listener: (data: EventData.TestPass) => void): this;
prependOnceListener(event: "test:plan", listener: (data: EventData.TestPlan) => void): this;
prependOnceListener(event: "test:start", listener: (data: EventData.TestStart) => void): this;
prependOnceListener(event: "test:stderr", listener: (data: EventData.TestStderr) => void): this;
prependOnceListener(event: "test:stdout", listener: (data: EventData.TestStdout) => void): this;
prependOnceListener(event: "test:summary", listener: (data: EventData.TestSummary) => void): this;
prependOnceListener(event: "test:watch:drained", listener: () => void): this;
prependOnceListener(event: string, listener: (...args: any[]) => void): this;
}
namespace EventData {
interface Error extends globalThis.Error {
cause: globalThis.Error;
}
interface LocationInfo {
/**
* 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 was run through the REPL.
*/
file?: string;
/**
* The line number where the test is defined, or `undefined` if the test was run through the REPL.
*/
line?: number;
}
interface TestDiagnostic extends LocationInfo {
/**
* The diagnostic message.
*/
message: string;
/**
* The nesting level of the test.
*/
nesting: number;
}
interface TestCoverage {
/**
* An object containing the coverage report.
*/
summary: {
/**
* An array of coverage reports for individual files.
*/
files: Array<{
/**
* The absolute path of the file.
*/
path: string;
/**
* The total number of lines.
*/
totalLineCount: number;
/**
* The total number of branches.
*/
totalBranchCount: number;
/**
* The total number of functions.
*/
totalFunctionCount: number;
/**
* The number of covered lines.
*/
coveredLineCount: number;
/**
* The number of covered branches.
*/
coveredBranchCount: number;
/**
* The number of covered functions.
*/
coveredFunctionCount: number;
/**
* The percentage of lines covered.
*/
coveredLinePercent: number;
/**
* The percentage of branches covered.
*/
coveredBranchPercent: number;
/**
* The percentage of functions covered.
*/
coveredFunctionPercent: number;
/**
* An array of functions representing function coverage.
*/
functions: Array<{
/**
* The name of the function.
*/
name: string;
/**
* The line number where the function is defined.
*/
line: number;
/**
* The number of times the function was called.
*/
count: number;
}>;
/**
* An array of branches representing branch coverage.
*/
branches: Array<{
/**
* The line number where the branch is defined.
*/
line: number;
/**
* The number of times the branch was taken.
*/
count: number;
}>;
/**
* An array of lines representing line numbers and the number of times they were covered.
*/
lines: Array<{
/**
* The line number.
*/
line: number;
/**
* The number of times the line was covered.
*/
count: number;
}>;
}>;
/**
* An object containing whether or not the coverage for
* each coverage type.
* @since v22.9.0
*/
thresholds: {
/**
* The function coverage threshold.
*/
function: number;
/**
* The branch coverage threshold.
*/
branch: number;
/**
* The line coverage threshold.
*/
line: number;
};
/**
* An object containing a summary of coverage for all files.
*/
totals: {
/**
* The total number of lines.
*/
totalLineCount: number;
/**
* The total number of branches.
*/
totalBranchCount: number;
/**
* The total number of functions.
*/
totalFunctionCount: number;
/**
* The number of covered lines.
*/
coveredLineCount: number;
/**
* The number of covered branches.
*/
coveredBranchCount: number;
/**
* The number of covered functions.
*/
coveredFunctionCount: number;
/**
* The percentage of lines covered.
*/
coveredLinePercent: number;
/**
* The percentage of branches covered.
*/
coveredBranchPercent: number;
/**
* The percentage of functions covered.
*/
coveredFunctionPercent: number;
};
/**
* The working directory when code coverage began. This
* is useful for displaying relative path names in case
* the tests changed the working directory of the Node.js process.
*/
workingDirectory: string;
};
/**
* The nesting level of the test.
*/
nesting: number;
}
interface TestComplete extends LocationInfo {
/**
* Additional execution metadata.
*/
details: {
/**
* Whether the test passed or not.
*/
passed: boolean;
/**
* The duration of the test in milliseconds.
*/
duration_ms: number;
/**
* An error wrapping the error thrown by the test if it did not pass.
*/
error?: Error;
/**
* The type of the test, used to denote whether this is a suite.
*/
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 TestDequeue extends LocationInfo {
/**
* The test name.
*/
name: string;
/**
* The nesting level of the test.
*/
nesting: number;
/**
* The test type. Either `'suite'` or `'test'`.
* @since v22.15.0
*/
type: "suite" | "test";
}
interface TestEnqueue extends LocationInfo {
/**
* The test name.
*/
name: string;
/**
* The nesting level of the test.
*/
nesting: number;
/**
* The test type. Either `'suite'` or `'test'`.
* @since v22.15.0
*/
type: "suite" | "test";
}
interface TestFail extends LocationInfo {
/**
* Additional execution metadata.
*/
details: {
/**
* The duration of the test in milliseconds.
*/
duration_ms: number;
/**
* An error wrapping the error thrown by the test.
*/
error: Error;
/**
* The type of the test, used to denote whether this is a suite.
* @since v20.0.0, v19.9.0, v18.17.0
*/
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 LocationInfo {
/**
* 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 LocationInfo {
/**
* The nesting level of the test.
*/
nesting: number;
/**
* The number of subtests that have ran.
*/
count: number;
}
interface TestStart extends LocationInfo {
/**
* The test name.
*/
name: string;
/**
* The nesting level of the test.
*/
nesting: number;
}
interface TestStderr {
/**
* The path of the test file.
*/
file: string;
/**
* The message written to `stderr`.
*/
message: string;
}
interface TestStdout {
/**
* The path of the test file.
*/
file: string;
/**
* The message written to `stdout`.
*/
message: string;
}
interface TestSummary {
/**
* An object containing the counts of various test results.
*/
counts: {
/**
* The total number of cancelled tests.
*/
cancelled: number;
/**
* The total number of passed tests.
*/
passed: number;
/**
* The total number of skipped tests.
*/
skipped: number;
/**
* The total number of suites run.
*/
suites: number;
/**
* The total number of tests run, excluding suites.
*/
tests: number;
/**
* The total number of TODO tests.
*/
todo: number;
/**
* The total number of top level tests and suites.
*/
topLevel: number;
};
/**
* The duration of the test run in milliseconds.
*/
duration_ms: number;
/**
* The path of the test file that generated the
* summary. If the summary corresponds to multiple files, this value is
* `undefined`.
*/
file: string | undefined;
/**
* Indicates whether or not the test run is considered
* successful or not. If any error condition occurs, such as a failing test or
* unmet coverage threshold, this value will be set to `false`.
*/
success: boolean;
}
}
/**
* 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
*/
interface TestContext {
/**
* An object containing assertion methods bound to the test context.
* The top-level functions from the `node:assert` module are exposed here for the purpose of creating test plans.
*
* **Note:** Some of the functions from `node:assert` contain type assertions. If these are called via the
* TestContext `assert` object, then the context parameter in the test's function signature **must be explicitly typed**
* (ie. the parameter must have a type annotation), otherwise an error will be raised by the TypeScript compiler:
* ```ts
* import { test, type TestContext } from 'node:test';
*
* // The test function's context parameter must have a type annotation.
* test('example', (t: TestContext) => {
* t.assert.deepStrictEqual(actual, expected);
* });
*
* // Omitting the type annotation will result in a compilation error.
* test('example', t => {
* t.assert.deepStrictEqual(actual, expected); // Error: 't' needs an explicit type annotation.
* });
* ```
* @since v22.2.0, v20.15.0
*/
readonly assert: TestContextAssert;
/**
* This function is used to create a hook running before subtest of the current test.
* @param fn The hook function. The first argument to this function is a `TestContext` object.
* If the hook uses callbacks, the callback function is passed as the second argument.
* @param options Configuration options for the hook.
* @since v20.1.0, v18.17.0
*/
before(fn?: TestContextHookFn, options?: HookOptions): void;
/**
* This function is used to create a hook running before each subtest of the current test.
* @param fn The hook function. The first argument to this function is a `TestContext` object.
* If the hook uses callbacks, the callback function is passed as the second argument.
* @param options Configuration options for the hook.
* @since v18.8.0
*/
beforeEach(fn?: TestContextHookFn, options?: HookOptions): void;
/**
* This function is used to create a hook that runs after the current test finishes.
* @param fn The hook function. The first argument to this function is a `TestContext` object.
* If the hook uses callbacks, the callback function is passed as the second argument.
* @param options Configuration options for the hook.
* @since v18.13.0
*/
after(fn?: TestContextHookFn, options?: HookOptions): void;
/**
* This function is used to create a hook running after each subtest of the current test.
* @param fn The hook function. The first argument to this function is a `TestContext` object.
* If the hook uses callbacks, the callback function is passed as the second argument.
* @param options Configuration options for the hook.
* @since v18.8.0
*/
afterEach(fn?: TestContextHookFn, options?: HookOptions): void;
/**
* 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 absolute path of the test file that created the current test. If a test file imports
* additional modules that generate tests, the imported tests will return the path of the root test file.
* @since v22.6.0
*/
readonly filePath: string | undefined;
/**
* The name of the test and each of its ancestors, separated by `>`.
* @since v22.3.0
*/
readonly fullName: string;
/**
* The name of the test.
* @since v18.8.0, v16.18.0
*/
readonly name: string;
/**
* This function is used to set the number of assertions and subtests that are expected to run
* within the test. If the number of assertions and subtests that run does not match the
* expected count, the test will fail.
*
* > Note: To make sure assertions are tracked, `t.assert` must be used instead of `assert` directly.
*
* ```js
* test('top level test', (t) => {
* t.plan(2);
* t.assert.ok('some relevant assertion here');
* t.test('subtest', () => {});
* });
* ```
*
* When working with asynchronous code, the `plan` function can be used to ensure that the
* correct number of assertions are run:
*
* ```js
* test('planning with streams', (t, done) => {
* function* generate() {
* yield 'a';
* yield 'b';
* yield 'c';
* }
* const expected = ['a', 'b', 'c'];
* t.plan(expected.length);
* const stream = Readable.from(generate());
* stream.on('data', (chunk) => {
* t.assert.strictEqual(chunk, expected.shift());
* });
*
* stream.on('end', () => {
* done();
* });
* });
* ```
*
* When using the `wait` option, you can control how long the test will wait for the expected assertions.
* For example, setting a maximum wait time ensures that the test will wait for asynchronous assertions
* to complete within the specified timeframe:
*
* ```js
* test('plan with wait: 2000 waits for async assertions', (t) => {
* t.plan(1, { wait: 2000 }); // Waits for up to 2 seconds for the assertion to complete.
*
* const asyncActivity = () => {
* setTimeout(() => {
* * t.assert.ok(true, 'Async assertion completed within the wait time');
* }, 1000); // Completes after 1 second, within the 2-second wait time.
* };
*
* asyncActivity(); // The test will pass because the assertion is completed in time.
* });
* ```
*
* Note: If a `wait` timeout is specified, it begins counting down only after the test function finishes executing.
* @since v22.2.0
*/
plan(count: number, options?: TestContextPlanOptions): void;
/**
* 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.
* Defaults to the `name` property of `fn`, or `'<anonymous>'` 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.
* @returns A {@link Promise} resolved with `undefined` once the test completes.
*/
test: typeof test;
/**
* This method polls a `condition` function until that function either returns
* successfully or the operation times out.
* @since v22.14.0
* @param condition An assertion function that is invoked
* periodically until it completes successfully or the defined polling timeout
* elapses. Successful completion is defined as not throwing or rejecting. This
* function does not accept any arguments, and is allowed to return any value.
* @param options An optional configuration object for the polling operation.
* @returns Fulfilled with the value returned by `condition`.
*/
waitFor<T>(condition: () => T, options?: TestContextWaitForOptions): Promise<Awaited<T>>;
/**
* Each test provides its own MockTracker instance.
*/
readonly mock: MockTracker;
}
interface TestContextAssert extends
Pick<
typeof import("assert"),
| "deepEqual"
| "deepStrictEqual"
| "doesNotMatch"
| "doesNotReject"
| "doesNotThrow"
| "equal"
| "fail"
| "ifError"
| "match"
| "notDeepEqual"
| "notDeepStrictEqual"
| "notEqual"
| "notStrictEqual"
| "ok"
| "partialDeepStrictEqual"
| "rejects"
| "strictEqual"
| "throws"
>
{
/**
* This function serializes `value` and writes it to the file specified by `path`.
*
* ```js
* test('snapshot test with default serialization', (t) => {
* t.assert.fileSnapshot({ value1: 1, value2: 2 }, './snapshots/snapshot.json');
* });
* ```
*
* This function differs from `context.assert.snapshot()` in the following ways:
*
* * The snapshot file path is explicitly provided by the user.
* * Each snapshot file is limited to a single snapshot value.
* * No additional escaping is performed by the test runner.
*
* These differences allow snapshot files to better support features such as syntax
* highlighting.
* @since v22.14.0
* @param value A value to serialize to a string. If Node.js was started with
* the [`--test-update-snapshots`](https://nodejs.org/docs/latest-v24.x/api/cli.html#--test-update-snapshots)
* flag, the serialized value is written to
* `path`. Otherwise, the serialized value is compared to the contents of the
* existing snapshot file.
* @param path The file where the serialized `value` is written.
* @param options Optional configuration options.
*/
fileSnapshot(value: any, path: string, options?: AssertSnapshotOptions): void;
/**
* This function implements assertions for snapshot testing.
* ```js
* test('snapshot test with default serialization', (t) => {
* t.assert.snapshot({ value1: 1, value2: 2 });
* });
*
* test('snapshot test with custom serialization', (t) => {
* t.assert.snapshot({ value3: 3, value4: 4 }, {
* serializers: [(value) => JSON.stringify(value)]
* });
* });
* ```
* @since v22.3.0
* @param value A value to serialize to a string. If Node.js was started with
* the [`--test-update-snapshots`](https://nodejs.org/docs/latest-v24.x/api/cli.html#--test-update-snapshots)
* flag, the serialized value is written to
* the snapshot file. Otherwise, the serialized value is compared to the
* corresponding value in the existing snapshot file.
*/
snapshot(value: any, options?: AssertSnapshotOptions): void;
/**
* A custom assertion function registered with `assert.register()`.
*/
[name: string]: (...args: any[]) => void;
}
interface AssertSnapshotOptions {
/**
* An array of synchronous functions used to serialize `value` into a string.
* `value` is passed as the only argument to the first serializer function.
* The return value of each serializer is passed as input to the next serializer.
* Once all serializers have run, the resulting value is coerced to a string.
*
* If no serializers are provided, the test runner's default serializers are used.
*/
serializers?: ReadonlyArray<(value: any) => any> | undefined;
}
interface TestContextPlanOptions {
/**
* The wait time for the plan:
* * If `true`, the plan waits indefinitely for all assertions and subtests to run.
* * If `false`, the plan performs an immediate check after the test function completes,
* without waiting for any pending assertions or subtests.
* Any assertions or subtests that complete after this check will not be counted towards the plan.
* * If a number, it specifies the maximum wait time in milliseconds
* before timing out while waiting for expected assertions and subtests to be matched.
* If the timeout is reached, the test will fail.
* @default false
*/
wait?: boolean | number | undefined;
}
interface TestContextWaitForOptions {
/**
* The number of milliseconds to wait after an unsuccessful
* invocation of `condition` before trying again.
* @default 50
*/
interval?: number | undefined;
/**
* The poll timeout in milliseconds. If `condition` has not
* succeeded by the time this elapses, an error occurs.
* @default 1000
*/
timeout?: number | undefined;
}
/**
* 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
*/
interface SuiteContext {
/**
* The absolute path of the test file that created the current suite. If a test file imports
* additional modules that generate suites, the imported suites will return the path of the root test file.
* @since v22.6.0
*/
readonly filePath: string | undefined;
/**
* 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;
/**
* The number of assertions and subtests expected to be run in the test.
* If the number of assertions run in the test does not match the number
* specified in the plan, the test will fail.
* @default undefined
* @since v22.2.0
*/
plan?: number | undefined;
}
/**
* This function creates a hook that runs before executing 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 The hook function. If the hook uses callbacks, the callback function is passed as the second argument.
* @param options Configuration options for the hook.
*/
function before(fn?: HookFn, options?: HookOptions): void;
/**
* This function creates a hook that runs after executing 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 The hook function. If the hook uses callbacks, the callback function is passed as the second argument.
* @param options Configuration options for the hook.
*/
function after(fn?: HookFn, options?: HookOptions): void;
/**
* This function creates a hook that runs before each test in 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 The hook function. If the hook uses callbacks, the callback function is passed as the second argument.
* @param options Configuration options for the hook.
*/
function beforeEach(fn?: HookFn, options?: HookOptions): void;
/**
* This function creates a hook that runs after each test in the current suite.
* The `afterEach()` hook is run even if the test fails.
*
* ```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 The hook function. If the hook uses callbacks, the callback function is passed as the second argument.
* @param options Configuration options for the hook.
*/
function afterEach(fn?: HookFn, options?: HookOptions): void;
/**
* The hook function. The first argument is the context in which the hook is called.
* If the hook uses callbacks, the callback function is passed as the second argument.
*/
type HookFn = (c: TestContext | SuiteContext, done: (result?: any) => void) => any;
/**
* The hook function. The first argument is a `TestContext` object.
* If the hook uses callbacks, the callback function is passed as the second argument.
*/
type TestContextHookFn = (t: TestContext, 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 extends Function> = F & {
mock: MockFunctionContext<F>;
};
interface MockModuleOptions {
/**
* If false, each call to `require()` or `import()` generates a new mock module.
* If true, subsequent calls will return the same module mock, and the mock module is inserted into the CommonJS cache.
* @default false
*/
cache?: boolean | undefined;
/**
* The value to use as the mocked module's default export.
*
* If this value is not provided, ESM mocks do not include a default export.
* If the mock is a CommonJS or builtin module, this setting is used as the value of `module.exports`.
* If this value is not provided, CJS and builtin mocks use an empty object as the value of `module.exports`.
*/
defaultExport?: any;
/**
* An object whose keys and values are used to create the named exports of the mock module.
*
* If the mock is a CommonJS or builtin module, these values are copied onto `module.exports`.
* Therefore, if a mock is created with both named exports and a non-object default export,
* the mock will throw an exception when used as a CJS or builtin module.
*/
namedExports?: object | undefined;
}
/**
* 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
*/
interface 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 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.
* @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<F extends Function = (...args: any[]) => undefined>(
original?: F,
options?: MockFunctionOptions,
): Mock<F>;
fn<F extends Function = (...args: any[]) => undefined, Implementation extends Function = F>(
original?: F,
implementation?: Implementation,
options?: MockFunctionOptions,
): Mock<F | Implementation>;
/**
* 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.
* @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<MockedObject>,
>(
object: MockedObject,
methodName: MethodName,
options?: MockFunctionOptions,
): MockedObject[MethodName] extends Function ? Mock<MockedObject[MethodName]>
: never;
method<
MockedObject extends object,
MethodName extends FunctionPropertyNames<MockedObject>,
Implementation extends Function,
>(
object: MockedObject,
methodName: MethodName,
implementation: Implementation,
options?: MockFunctionOptions,
): MockedObject[MethodName] extends Function ? Mock<MockedObject[MethodName] | Implementation>
: never;
method<MockedObject extends object>(
object: MockedObject,
methodName: keyof MockedObject,
options: MockMethodOptions,
): Mock<Function>;
method<MockedObject extends object>(
object: MockedObject,
methodName: keyof MockedObject,
implementation: Function,
options: MockMethodOptions,
): Mock<Function>;
/**
* 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 is used to mock the exports of ECMAScript modules, CommonJS modules, JSON modules, and
* Node.js builtin modules. Any references to the original module prior to mocking are not impacted. In
* order to enable module mocking, Node.js must be started with the
* [`--experimental-test-module-mocks`](https://nodejs.org/docs/latest-v24.x/api/cli.html#--experimental-test-module-mocks)
* command-line flag.
*
* The following example demonstrates how a mock is created for a module.
*
* ```js
* test('mocks a builtin module in both module systems', async (t) => {
* // Create a mock of 'node:readline' with a named export named 'fn', which
* // does not exist in the original 'node:readline' module.
* const mock = t.mock.module('node:readline', {
* namedExports: { fn() { return 42; } },
* });
*
* let esmImpl = await import('node:readline');
* let cjsImpl = require('node:readline');
*
* // cursorTo() is an export of the original 'node:readline' module.
* assert.strictEqual(esmImpl.cursorTo, undefined);
* assert.strictEqual(cjsImpl.cursorTo, undefined);
* assert.strictEqual(esmImpl.fn(), 42);
* assert.strictEqual(cjsImpl.fn(), 42);
*
* mock.restore();
*
* // The mock is restored, so the original builtin module is returned.
* esmImpl = await import('node:readline');
* cjsImpl = require('node:readline');
*
* assert.strictEqual(typeof esmImpl.cursorTo, 'function');
* assert.strictEqual(typeof cjsImpl.cursorTo, 'function');
* assert.strictEqual(esmImpl.fn, undefined);
* assert.strictEqual(cjsImpl.fn, undefined);
* });
* ```
* @since v22.3.0
* @experimental
* @param specifier A string identifying the module to mock.
* @param options Optional configuration options for the mock module.
*/
module(specifier: string, options?: MockModuleOptions): MockModuleContext;
/**
* 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;
readonly 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
*/
interface MockFunctionContext<F extends Function> {
/**
* 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: MockFunctionCall<F>[];
/**
* 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: F): 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: F, 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;
}
/**
* @since v22.3.0
* @experimental
*/
interface MockModuleContext {
/**
* Resets the implementation of the mock module.
* @since v22.3.0
*/
restore(): void;
}
interface MockTimersOptions {
apis: ReadonlyArray<"setInterval" | "setTimeout" | "setImmediate" | "Date">;
now?: number | Date | undefined;
}
/**
* 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
*/
interface 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;
}
/**
* An object whose methods are used to configure available assertions on the
* `TestContext` objects in the current process. The methods from `node:assert`
* and snapshot testing functions are available by default.
*
* It is possible to apply the same configuration to all files by placing common
* configuration code in a module
* preloaded with `--require` or `--import`.
* @since v22.14.0
*/
namespace assert {
/**
* Defines a new assertion function with the provided name and function. If an
* assertion already exists with the same name, it is overwritten.
* @since v22.14.0
*/
function register(name: string, fn: (this: TestContext, ...args: any[]) => void): void;
}
/**
* @since v22.3.0
*/
namespace snapshot {
/**
* This function is used to customize the default serialization mechanism used by the test runner.
*
* By default, the test runner performs serialization by calling `JSON.stringify(value, null, 2)` on the provided value.
* `JSON.stringify()` does have limitations regarding circular structures and supported data types.
* If a more robust serialization mechanism is required, this function should be used to specify a list of custom serializers.
*
* Serializers are called in order, with the output of the previous serializer passed as input to the next.
* The final result must be a string value.
* @since v22.3.0
* @param serializers An array of synchronous functions used as the default serializers for snapshot tests.
*/
function setDefaultSnapshotSerializers(serializers: ReadonlyArray<(value: any) => any>): void;
/**
* This function is used to set a custom resolver for the location of the snapshot file used for snapshot testing.
* By default, the snapshot filename is the same as the entry point filename with `.snapshot` appended.
* @since v22.3.0
* @param fn A function used to compute the location of the snapshot file.
* The function receives the path of the test file as its only argument. If the
* test is not associated with a file (for example in the REPL), the input is
* undefined. `fn()` must return a string specifying the location of the snapshot file.
*/
function setResolveSnapshotPath(fn: (path: string | undefined) => string): void;
}
}
type FunctionPropertyNames<T> = {
[K in keyof T]: T[K] extends Function ? K : never;
}[keyof T];
export = test;
}
/**
* 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 'node:test/reporters';
* ```
* @since v19.9.0
* @see [source](https://github.com/nodejs/node/blob/v24.x/lib/test/reporters.js)
*/
declare module "node:test/reporters" {
import { Transform, TransformOptions } from "node:stream";
import { EventData } from "node:test";
type TestEvent =
| { type: "test:coverage"; data: EventData.TestCoverage }
| { type: "test:complete"; data: EventData.TestComplete }
| { type: "test:dequeue"; data: EventData.TestDequeue }
| { type: "test:diagnostic"; data: EventData.TestDiagnostic }
| { type: "test:enqueue"; data: EventData.TestEnqueue }
| { type: "test:fail"; data: EventData.TestFail }
| { type: "test:pass"; data: EventData.TestPass }
| { type: "test:plan"; data: EventData.TestPlan }
| { type: "test:start"; data: EventData.TestStart }
| { type: "test:stderr"; data: EventData.TestStderr }
| { type: "test:stdout"; data: EventData.TestStdout }
| { type: "test:summary"; data: EventData.TestSummary }
| { type: "test:watch:drained"; data: undefined };
type TestEventGenerator = AsyncGenerator<TestEvent, void>;
interface ReporterConstructorWrapper<T extends new(...args: any[]) => Transform> {
new(...args: ConstructorParameters<T>): InstanceType<T>;
(...args: ConstructorParameters<T>): InstanceType<T>;
}
/**
* 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`.
* @since v20.0.0
*/
function dot(source: TestEventGenerator): AsyncGenerator<"\n" | "." | "X", void>;
/**
* The `tap` reporter outputs the test results in the [TAP](https://testanything.org/) format.
* @since v20.0.0
*/
function tap(source: TestEventGenerator): AsyncGenerator<string, void>;
class SpecReporter extends Transform {
constructor();
}
/**
* The `spec` reporter outputs the test results in a human-readable format.
* @since v20.0.0
*/
const spec: ReporterConstructorWrapper<typeof SpecReporter>;
/**
* The `junit` reporter outputs test results in a jUnit XML format.
* @since v21.0.0
*/
function junit(source: TestEventGenerator): AsyncGenerator<string, void>;
class LcovReporter extends Transform {
constructor(opts?: Omit<TransformOptions, "writableObjectMode">);
}
/**
* The `lcov` reporter outputs test coverage when used with the
* [`--experimental-test-coverage`](https://nodejs.org/docs/latest-v24.x/api/cli.html#--experimental-test-coverage) flag.
* @since v22.0.0
*/
const lcov: ReporterConstructorWrapper<typeof LcovReporter>;
export { dot, junit, lcov, spec, tap, TestEvent };
}