The TestBase class is the parent class of @tapjs/test!index.Test, and passed to all plugins at instantiation time.

This implements subtest functionality, TAP stream generation, lifecycle events, and only the basic pass/fail assertion methods.

All other features are added with plugins.

Hierarchy (view full)

Constructors

Properties

Accessors

Methods

Assertion Methods

Internal Machinery

Subtest Methods

Test Lifecycle Management

Test Reflection

Constructors

Properties

#awaitingEnd: boolean | typeof IMPLICIT = false
#calledOnEOF: boolean = false
#context: any = unsetContext

Any arbitrary data that is provided to this test object. Often, this is set in a t.before() or t.beforeEach() method. Scalar values are inherited by child tests. Object values are extended in child tests using Object.create().

#currentAssert?: Function | ((..._) => any)

Type declaration

    • (..._): any
    • Parameters

      • Rest ..._: any

      Returns any

#doingStdinOnly: boolean = false
#endingAll: boolean = false
#endingAllSub: boolean = false
#explicitEnded: boolean = false
#explicitPlan: boolean = false
#jobIds: Set<number>
#multiEndThrew: boolean = false
#n: number = 0
#nextChildId: number = 1
#noparallel: boolean = false
#occupied: null | Base<TapBaseEvents> | Waiter = null
#planAt?: CallSiteLike
#planEnd: number = -1
#printedOutput: boolean = false
#printedResult: boolean = false
#processing: boolean = false
#promiseEnded: boolean = false
#pushedBeforeEnd: boolean = false
#started: boolean = false
#writable: boolean = true
[ABORTED]: boolean
[ASYNC]: boolean
[BUFFERLENGTH]: number
[BUFFER]: string[]
[CLOSED]: boolean
[DATALISTENERS]: number
[DECODER]: null | SD
[DESTROYED]: boolean
[DISCARDED]: boolean
[EMITTED_END]: boolean
[EMITTED_ERROR]: unknown
[EMITTING_END]: boolean
[ENCODING]: null | BufferEncoding
[EOF]: boolean
[FLOWING]: boolean
[OBJECTMODE]: boolean
[PAUSED]: boolean
[PIPES]: Pipe<string>[]
[SIGNAL]?: AbortSignal
bail: boolean

Bail out on the first failed test point

childId: number

Numeric identifier for this test

debug: ((...args) => void)

Method that writes to stderr when debug: true is set in the options, or no-ops otherwise

Type declaration

    • (...args): void
    • Parameters

      • Rest ...args: any[]

      Returns void

diagnostic: null | boolean = null

Show diagnostics for this test. A value of null means that diagnostics will be shown only if the test is failing.

ended: boolean = false

Set true when @tapjs/core!test-base.TestBase#end is called

indent: string

number of spaces to indent the TAP stream

nestingLevel: number = 0

Nesting level, for serialization to node test runner

Note that this is zero for parent-less tests, and also zero for the first level of children.

omitVersion: boolean

Do not emit the TAP version 14 line at the start

options: TestBaseOpts

Options provided to this test

preserveWhitespace: boolean

Do not elide extraneous whitespace and empty lines.

readable: boolean

true if the stream can be read

readyToProcess: boolean = false

Set upon test completion when a child test is ready to be processed by its parent.

silent: boolean

True if this test should be buffered and only emit data if it fails

strict: boolean

Treat non-TAP data as an error. May be set with pragma +strict in the TAP stream, or unset with pragma: -strict.

timedOut: boolean = false

Set to true when the test times out, so its failure status can be determined later.

writable: boolean

true if the stream can be written

captureRejectionSymbol: typeof captureRejectionSymbol

Value: Symbol.for('nodejs.rejection')

See how to write a custom rejection handler.

Since

v13.4.0, v12.16.0

captureRejections: boolean

Value: boolean

Change the default captureRejections option on all new EventEmitter objects.

Since

v13.4.0, v12.16.0

defaultMaxListeners: number

By default, a maximum of 10 listeners can be registered for any single event. This limit can be changed for individual EventEmitter instances using the emitter.setMaxListeners(n) method. To change the default for allEventEmitter instances, the events.defaultMaxListeners property can be used. If this value is not a positive number, a RangeError is thrown.

Take caution when setting the events.defaultMaxListeners because the change affects all EventEmitter instances, including those created before the change is made. However, calling emitter.setMaxListeners(n) still has precedence over events.defaultMaxListeners.

This is not a hard limit. The EventEmitter instance will allow more listeners to be added but will output a trace warning to stderr indicating that a "possible EventEmitter memory leak" has been detected. For any single EventEmitter, the emitter.getMaxListeners() and emitter.setMaxListeners() methods can be used to temporarily avoid this warning:

import { EventEmitter } from 'node:events';
const emitter = new EventEmitter();
emitter.setMaxListeners(emitter.getMaxListeners() + 1);
emitter.once('event', () => {
// do stuff
emitter.setMaxListeners(Math.max(emitter.getMaxListeners() - 1, 0));
});

The --trace-warnings command-line flag can be used to display the stack trace for such warnings.

The emitted warning can be inspected with process.on('warning') and will have the additional emitter, type, and count properties, referring to the event emitter instance, the event's name and the number of attached listeners, respectively. Its name property is set to 'MaxListenersExceededWarning'.

Since

v0.11.2

errorMonitor: typeof errorMonitor

This symbol shall be used to install a listener for only monitoring 'error' events. Listeners installed using this symbol are called before the regular 'error' listeners are called.

Installing a listener using this symbol does not change the behavior once an 'error' event is emitted. Therefore, the process will still crash if no regular 'error' listener is installed.

Since

v13.6.0, v12.17.0

Accessors

  • get aborted(): boolean
  • True if the stream has been aborted.

    Returns boolean

  • set aborted(_): void
  • No-op setter. Stream aborted status is set via the AbortSignal provided in the constructor options.

    Parameters

    • _: boolean

    Returns void

  • get async(): boolean
  • true if this is an async stream

    Returns boolean

  • set async(a): void
  • Set to true to make this stream async.

    Once set, it cannot be unset, as this would potentially cause incorrect behavior. Ie, a sync stream can be made async, but an async stream cannot be safely made sync.

    Parameters

    • a: boolean

    Returns void

  • get bufferLength(): number
  • The amount of data stored in the buffer waiting to be read.

    For Buffer strings, this will be the total byte length. For string encoding streams, this will be the string character length, according to JavaScript's string.length logic. For objectMode streams, this is a count of the items waiting to be emitted.

    Returns number

  • get destroyed(): boolean
  • true if the stream has been forcibly destroyed

    Returns boolean

  • get emittedEnd(): boolean
  • true if the 'end' event has been emitted

    Returns boolean

  • get encoding(): null | BufferEncoding
  • The BufferEncoding currently in use, or null

    Returns null | BufferEncoding

  • set encoding(_enc): void
  • Parameters

    • _enc: null | BufferEncoding

    Returns void

    Deprecated

    • This is a read only property
  • get flowing(): boolean
  • true if the stream is currently in a flowing state, meaning that any writes will be immediately emitted.

    Returns boolean

  • get fullname(): string
  • The full name of the test, starting with the main script name, and including all parent names.

    Returns string

  • get objectMode(): boolean
  • True if this is an objectMode stream

    Returns boolean

  • set objectMode(_om): void
  • Parameters

    • _om: boolean

    Returns void

    Deprecated

    • This is a read-only property
  • get paused(): boolean
  • true if the stream is currently in a paused state

    Returns boolean

  • get streamWritable(): boolean
  • Boolean indicating whether the underlying stream can be written to, or if it has been ended.

    Returns boolean

  • get isStream(): ((s) => s is WriteStream | ReadStream | Minipass<any, any, any> | ReadStream & {
        fd: number;
    } | EventEmitter<DefaultEventMap> & {
        pause(): any;
        pipe(...destArgs): any;
        resume(): any;
    } | WriteStream & {
        fd: number;
    } | EventEmitter<DefaultEventMap> & {
        end(): any;
        write(chunk, ...args): any;
    })
  • Alias for isStream

    Former export location, maintained for backwards compatibility.

    Returns ((s) => s is WriteStream | ReadStream | Minipass<any, any, any> | ReadStream & {
        fd: number;
    } | EventEmitter<DefaultEventMap> & {
        pause(): any;
        pipe(...destArgs): any;
        resume(): any;
    } | WriteStream & {
        fd: number;
    } | EventEmitter<DefaultEventMap> & {
        end(): any;
        write(chunk, ...args): any;
    })

      • (s): s is WriteStream | ReadStream | Minipass<any, any, any> | ReadStream & {
            fd: number;
        } | EventEmitter<DefaultEventMap> & {
            pause(): any;
            pipe(...destArgs): any;
            resume(): any;
        } | WriteStream & {
            fd: number;
        } | EventEmitter<DefaultEventMap> & {
            end(): any;
            write(chunk, ...args): any;
        }
      • Parameters

        • s: any

        Returns s is WriteStream | ReadStream | Minipass<any, any, any> | ReadStream & {
            fd: number;
        } | EventEmitter<DefaultEventMap> & {
            pause(): any;
            pipe(...destArgs): any;
            resume(): any;
        } | WriteStream & {
            fd: number;
        } | EventEmitter<DefaultEventMap> & {
            end(): any;
            write(chunk, ...args): any;
        }

    Deprecated

Methods

  • Returns void

  • Parameters

    • chunk: string

    Returns void

  • Returns string

  • Parameters

    • data: string

    Returns boolean

  • Returns boolean

  • Returns boolean

  • Parameters

    • chunk: string

    Returns boolean

  • Parameters

    • Optional noDrain: boolean

    Returns void

  • Returns void

  • Parameters

    • n: null | number
    • chunk: string

    Returns string

  • Returns void

  • Asynchronous for await of iteration.

    This will continue emitting all chunks until the stream terminates.

    Returns AsyncGenerator<string, void, void>

  • Type Parameters

    • K

    Parameters

    • error: Error
    • event: string | symbol
    • Rest ...args: AnyRest

    Returns void

  • Synchronous for of iteration.

    The iteration will terminate when the internal buffer runs out, even if the stream has not yet terminated.

    Returns Generator<string, void, void>

  • Return a Promise that resolves to an array of all emitted data once the stream ends.

    Returns Promise<string[] & {
        dataLength: number;
    }>

  • output a TAP comment, formatted like console.log()

    If the test is currently awaiting a child test, it will be deferred until after the child test completes.

    If the test is already completed, the comment will be emitted on the parent, or if no parent is available, it will be printed to standard output.

    Parameters

    • Rest ...args: any[]

    Returns void

  • Return a Promise that resolves to the concatenation of all emitted data once the stream ends.

    Not allowed on objectMode streams.

    Returns Promise<string>

  • Destroy a stream, preventing it from being used for any further purpose.

    If the stream has a close() method, then it will be called on destruction.

    After destruction, any attempt to write data, read data, or emit most events will be ignored.

    If an error argument is provided, then it will be emitted in an 'error' event.

    Parameters

    • Optional er: unknown

    Returns this

  • Returns an array listing the events for which the emitter has registered listeners. The values in the array are strings or Symbols.

    import { EventEmitter } from 'node:events';

    const myEE = new EventEmitter();
    myEE.on('foo', () => {});
    myEE.on('bar', () => {});

    const sym = Symbol('symbol');
    myEE.on(sym, () => {});

    console.log(myEE.eventNames());
    // Prints: [ 'foo', 'bar', Symbol(symbol) ]

    Returns (string | symbol)[]

    Since

    v6.0.0

  • Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to defaultMaxListeners.

    Returns number

    Since

    v1.0.0

  • Returns the number of listeners listening for the event named eventName. If listener is provided, it will return how many times the listener is found in the list of the listeners of the event.

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol

      The name of the event being listened for

    • Optional listener: Function

      The event handler function

    Returns number

    Since

    v3.2.0

  • Returns a copy of the array of listeners for the event named eventName.

    server.on('connection', (stream) => {
    console.log('someone connected!');
    });
    console.log(util.inspect(server.listeners('connection')));
    // Prints: [ [Function] ]

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol

    Returns Function[]

    Since

    v0.1.26

  • Mostly identical to EventEmitter.off

    If a 'data' event handler is removed, and it was the last consumer (ie, there are no pipe destinations or other 'data' event listeners), then the flow of data will stop until there is another consumer or Minipass#resume is explicitly called.

    Type Parameters

    Parameters

    Returns this

  • Mostly identical to EventEmitter.on, with the following behavior differences to prevent data loss and unnecessary hangs:

    • Adding a 'data' event handler will trigger the flow of data

    • Adding a 'readable' event handler when there is data waiting to be read will cause 'readable' to be emitted immediately.

    • Adding an 'endish' event handler ('end', 'finish', etc.) which has already passed will cause the event to be emitted immediately and all handlers removed.

    • Adding an 'error' event handler after an error has been emitted will cause the event to be re-emitted immediately with the error previously raised.

    Type Parameters

    Parameters

    Returns this

  • Adds a one-time listener function for the event named eventName. The next time eventName is triggered, this listener is removed and then invoked.

    server.once('connection', (stream) => {
    console.log('Ah, we have our first user!');
    });

    Returns a reference to the EventEmitter, so that calls can be chained.

    By default, event listeners are invoked in the order they are added. The emitter.prependOnceListener() method can be used as an alternative to add the event listener to the beginning of the listeners array.

    import { EventEmitter } from 'node:events';
    const myEE = new EventEmitter();
    myEE.once('foo', () => console.log('a'));
    myEE.prependOnceListener('foo', () => console.log('b'));
    myEE.emit('foo');
    // Prints:
    // b
    // a

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol

      The name of the event.

    • listener: ((...args) => void)

      The callback function

        • (...args): void
        • Parameters

          • Rest ...args: any[]

          Returns void

    Returns this

    Since

    v0.3.0

  • Pause the stream

    Returns void

  • Pipe all data emitted by this stream into the destination provided.

    Triggers the flow of data.

    Type Parameters

    • W extends Writable

    Parameters

    • dest: W
    • Optional opts: PipeOptions

    Returns W

  • Set TAP pragma configs to affect the behavior of the parser. Only strict is supported by the parser.

    Parameters

    • set: {
          [k: string]: boolean;
      }
      • [k: string]: boolean

    Returns void

  • Adds the listener function to the beginning of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.

    server.prependListener('connection', (stream) => {
    console.log('someone connected!');
    });

    Returns a reference to the EventEmitter, so that calls can be chained.

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol

      The name of the event.

    • listener: ((...args) => void)

      The callback function

        • (...args): void
        • Parameters

          • Rest ...args: any[]

          Returns void

    Returns this

    Since

    v6.0.0

  • Adds a one-timelistener function for the event named eventName to the beginning of the listeners array. The next time eventName is triggered, this listener is removed, and then invoked.

    server.prependOnceListener('connection', (stream) => {
    console.log('Ah, we have our first user!');
    });

    Returns a reference to the EventEmitter, so that calls can be chained.

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol

      The name of the event.

    • listener: ((...args) => void)

      The callback function

        • (...args): void
        • Parameters

          • Rest ...args: any[]

          Returns void

    Returns this

    Since

    v6.0.0

  • Return a void Promise that resolves once the stream ends.

    Returns Promise<void>

  • Returns a copy of the array of listeners for the event named eventName, including any wrappers (such as those created by .once()).

    import { EventEmitter } from 'node:events';
    const emitter = new EventEmitter();
    emitter.once('log', () => console.log('log once'));

    // Returns a new Array with a function `onceWrapper` which has a property
    // `listener` which contains the original listener bound above
    const listeners = emitter.rawListeners('log');
    const logFnWrapper = listeners[0];

    // Logs "log once" to the console and does not unbind the `once` event
    logFnWrapper.listener();

    // Logs "log once" to the console and removes the listener
    logFnWrapper();

    emitter.on('log', () => console.log('log persistently'));
    // Will return a new Array with a single function bound by `.on()` above
    const newListeners = emitter.rawListeners('log');

    // Logs "log persistently" twice
    newListeners[0]();
    emitter.emit('log');

    Type Parameters

    • K

    Parameters

    • eventName: string | symbol

    Returns Function[]

    Since

    v9.4.0

  • Low-level explicit read method.

    In objectMode, the argument is ignored, and one item is returned if available.

    n is the number of bytes (or in the case of encoding streams, characters) to consume. If n is not provided, then the entire buffer is returned, or null is returned if no data is available.

    If n is greater that the amount of data in the internal buffer, then null is returned.

    Parameters

    • Optional n: null | number

    Returns null | string

  • Mostly identical to EventEmitter.removeAllListeners

    If all 'data' event handlers are removed, and they were the last consumer (ie, there are no pipe destinations), then the flow of data will stop until there is another consumer or Minipass#resume is explicitly called.

    Type Parameters

    Parameters

    Returns this

  • Resume the stream if it is currently in a paused state

    If called when there are no pipe destinations or data event listeners, this will place the stream in a "discarded" state, where all data will be thrown away. The discarded state is removed if a pipe destination or data handler is added, if pause() is called, or if any synchronous or asynchronous iteration is started.

    Returns void

  • Parameters

    • _enc: Encoding

    Returns void

    Deprecated

    • Encoding may only be set at instantiation time
  • By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) to indicate an unlimited number of listeners.

    Returns a reference to the EventEmitter, so that calls can be chained.

    Parameters

    • n: number

    Returns this

    Since

    v0.3.5

  • Fully unhook a piped destination stream.

    If the destination stream was the only consumer of this stream (ie, there are no other piped destinations or 'data' event listeners) then the flow of data will stop until there is another consumer or Minipass#resume is explicitly called.

    Type Parameters

    • W extends Writable

    Parameters

    • dest: W

    Returns void

  • Experimental

    Listens once to the abort event on the provided signal.

    Listening to the abort event on abort signals is unsafe and may lead to resource leaks since another third party with the signal can call e.stopImmediatePropagation(). Unfortunately Node.js cannot change this since it would violate the web standard. Additionally, the original API makes it easy to forget to remove listeners.

    This API allows safely using AbortSignals in Node.js APIs by solving these two issues by listening to the event such that stopImmediatePropagation does not prevent the listener from running.

    Returns a disposable so that it may be unsubscribed from more easily.

    import { addAbortListener } from 'node:events';

    function example(signal) {
    let disposable;
    try {
    signal.addEventListener('abort', (e) => e.stopImmediatePropagation());
    disposable = addAbortListener(signal, (e) => {
    // Do something when signal is aborted.
    });
    } finally {
    disposable?.[Symbol.dispose]();
    }
    }

    Parameters

    • signal: AbortSignal
    • resource: ((event) => void)
        • (event): void
        • Parameters

          • event: Event

          Returns void

    Returns Disposable

    Disposable that removes the abort listener.

    Since

    v20.5.0

  • Returns a copy of the array of listeners for the event named eventName.

    For EventEmitters this behaves exactly the same as calling .listeners on the emitter.

    For EventTargets this is the only way to get the event listeners for the event target. This is useful for debugging and diagnostic purposes.

    import { getEventListeners, EventEmitter } from 'node:events';

    {
    const ee = new EventEmitter();
    const listener = () => console.log('Events are fun');
    ee.on('foo', listener);
    console.log(getEventListeners(ee, 'foo')); // [ [Function: listener] ]
    }
    {
    const et = new EventTarget();
    const listener = () => console.log('Events are fun');
    et.addEventListener('foo', listener);
    console.log(getEventListeners(et, 'foo')); // [ [Function: listener] ]
    }

    Parameters

    • emitter: EventEmitter<DefaultEventMap> | EventTarget
    • name: string | symbol

    Returns Function[]

    Since

    v15.2.0, v14.17.0

  • Returns the currently set max amount of listeners.

    For EventEmitters this behaves exactly the same as calling .getMaxListeners on the emitter.

    For EventTargets this is the only way to get the max event listeners for the event target. If the number of event handlers on a single EventTarget exceeds the max set, the EventTarget will print a warning.

    import { getMaxListeners, setMaxListeners, EventEmitter } from 'node:events';

    {
    const ee = new EventEmitter();
    console.log(getMaxListeners(ee)); // 10
    setMaxListeners(11, ee);
    console.log(getMaxListeners(ee)); // 11
    }
    {
    const et = new EventTarget();
    console.log(getMaxListeners(et)); // 10
    setMaxListeners(11, et);
    console.log(getMaxListeners(et)); // 11
    }

    Parameters

    • emitter: EventEmitter<DefaultEventMap> | EventTarget

    Returns number

    Since

    v19.9.0

  • A class method that returns the number of listeners for the given eventName registered on the given emitter.

    import { EventEmitter, listenerCount } from 'node:events';

    const myEmitter = new EventEmitter();
    myEmitter.on('event', () => {});
    myEmitter.on('event', () => {});
    console.log(listenerCount(myEmitter, 'event'));
    // Prints: 2

    Parameters

    • emitter: EventEmitter<DefaultEventMap>

      The emitter to query

    • eventName: string | symbol

      The event name

    Returns number

    Since

    v0.9.12

    Deprecated

    Since v3.2.0 - Use listenerCount instead.

  • import { on, EventEmitter } from 'node:events';
    import process from 'node:process';

    const ee = new EventEmitter();

    // Emit later on
    process.nextTick(() => {
    ee.emit('foo', 'bar');
    ee.emit('foo', 42);
    });

    for await (const event of on(ee, 'foo')) {
    // The execution of this inner block is synchronous and it
    // processes one event at a time (even with await). Do not use
    // if concurrent execution is required.
    console.log(event); // prints ['bar'] [42]
    }
    // Unreachable here

    Returns an AsyncIterator that iterates eventName events. It will throw if the EventEmitter emits 'error'. It removes all listeners when exiting the loop. The value returned by each iteration is an array composed of the emitted event arguments.

    An AbortSignal can be used to cancel waiting on events:

    import { on, EventEmitter } from 'node:events';
    import process from 'node:process';

    const ac = new AbortController();

    (async () => {
    const ee = new EventEmitter();

    // Emit later on
    process.nextTick(() => {
    ee.emit('foo', 'bar');
    ee.emit('foo', 42);
    });

    for await (const event of on(ee, 'foo', { signal: ac.signal })) {
    // The execution of this inner block is synchronous and it
    // processes one event at a time (even with await). Do not use
    // if concurrent execution is required.
    console.log(event); // prints ['bar'] [42]
    }
    // Unreachable here
    })();

    process.nextTick(() => ac.abort());

    Parameters

    • emitter: EventEmitter<DefaultEventMap>
    • eventName: string

      The name of the event being listened for

    • Optional options: StaticEventEmitterOptions

    Returns AsyncIterableIterator<any>

    An AsyncIterator that iterates eventName events emitted by the emitter

    Since

    v13.6.0, v12.16.0

  • Creates a Promise that is fulfilled when the EventEmitter emits the given event or that is rejected if the EventEmitter emits 'error' while waiting. The Promise will resolve with an array of all the arguments emitted to the given event.

    This method is intentionally generic and works with the web platform EventTarget interface, which has no special'error' event semantics and does not listen to the 'error' event.

    import { once, EventEmitter } from 'node:events';
    import process from 'node:process';

    const ee = new EventEmitter();

    process.nextTick(() => {
    ee.emit('myevent', 42);
    });

    const [value] = await once(ee, 'myevent');
    console.log(value);

    const err = new Error('kaboom');
    process.nextTick(() => {
    ee.emit('error', err);
    });

    try {
    await once(ee, 'myevent');
    } catch (err) {
    console.error('error happened', err);
    }

    The special handling of the 'error' event is only used when events.once() is used to wait for another event. If events.once() is used to wait for the 'error' event itself, then it is treated as any other kind of event without special handling:

    import { EventEmitter, once } from 'node:events';

    const ee = new EventEmitter();

    once(ee, 'error')
    .then(([err]) => console.log('ok', err.message))
    .catch((err) => console.error('error', err.message));

    ee.emit('error', new Error('boom'));

    // Prints: ok boom

    An AbortSignal can be used to cancel waiting for the event:

    import { EventEmitter, once } from 'node:events';

    const ee = new EventEmitter();
    const ac = new AbortController();

    async function foo(emitter, event, signal) {
    try {
    await once(emitter, event, { signal });
    console.log('event emitted!');
    } catch (error) {
    if (error.name === 'AbortError') {
    console.error('Waiting for the event was canceled!');
    } else {
    console.error('There was an error', error.message);
    }
    }
    }

    foo(ee, 'foo', ac.signal);
    ac.abort(); // Abort waiting for the event
    ee.emit('foo'); // Prints: Waiting for the event was canceled!

    Parameters

    • emitter: EventEmitter<DefaultEventMap>
    • eventName: string | symbol
    • Optional options: StaticEventEmitterOptions

    Returns Promise<any[]>

    Since

    v11.13.0, v10.16.0

  • Parameters

    • emitter: EventTarget
    • eventName: string
    • Optional options: StaticEventEmitterOptions

    Returns Promise<any[]>

  • import { setMaxListeners, EventEmitter } from 'node:events';

    const target = new EventTarget();
    const emitter = new EventEmitter();

    setMaxListeners(5, target, emitter);

    Parameters

    • Optional n: number

      A non-negative number. The maximum number of listeners per EventTarget event.

    • Rest ...eventTargets: (EventEmitter<DefaultEventMap> | EventTarget)[]

    Returns void

    Since

    v15.4.0

Assertion Methods

Internal Machinery

activeSubtests: Set<Base<TapBaseEvents>> = ...

Subtests that are currently in process.

buffered: boolean

True if this test should be buffered and only processed on completion

cb?: ((...args) => any)

Function that will get this test as an argument when it is processed

Type declaration

    • (...args): any
    • Parameters

      • Rest ...args: any[]

      Returns any

deferred?: Deferred<FinalResults>

A Deferred promise wrapper that is resolved when this test completes.

donePromise?: Promise<any> & {
    tapAbortPromise?: (() => void);
}

A promise that resolves when the test is done.

Type declaration

  • Optional tapAbortPromise?: (() => void)
      • (): void
      • Returns void

hook: TapWrap

TapWrap AsyncResource that limits the async-hook-domain

hookDomain: Domain

the async-hook-domain that catches throws and Promise rejections

output: string

the TAP stream data for buffered tests

parent?: TestBase

Parent test of this TAP stream

parser: Parser

The tap parser attached to this TAP stream

pool: Set<Base<TapBaseEvents>> = ...

The pool of parallel tests currently in process

queue: QueueEntry[] = ...

Queue of items awaiting processing. Can be any @tapjs/core!test-base.QueueEntry item.

start: bigint

high resolution bigint time when this test started

subtests: Base<TapBaseEvents>[] = []

Array of all subtests that have been added/scheduled, and have not yet completed.

timer?: Timeout

The timer that fires when the test times out

  • get currentAssert(): undefined | Function | ((...a) => any)
  • The current assertion being processed. Set at the start of all assertions, and used for calculating stack traces.

    Returns undefined | Function | ((...a) => any)

  • set currentAssert(fn): void
  • Parameters

    • fn: undefined | Function | ((...a) => any)

    Returns void

  • Internal

    Method called when parser emits a line of TAP data

    Parameters

    • line: string

    Returns boolean

  • Internal

    Print a Test Point.

    Parameters

    • ok: boolean
    • message: string
    • extra: Extra
    • front: boolean = false

    Returns void

  • Internal

    Called when a test times out or bails out, or the process ends, marking all currently active or queued subtests as incomplete.

    No need to ever call this directly, exposed so that it can be extended by @tapjs/core!spawn.Spawn and @tapjs/core!worker.Worker, which have special behaviors that are required when a process hangs indefinitely.

    Parameters

    • sub: boolean = false

    Returns void

  • Internal

    The main function that starts a test running. Generally no need to call this directly.

    Parameters

    • cb: (() => void)
        • (): void
        • Returns void

    Returns void

  • Internal

    extension point for plugins that want to be notified when the test is completely done, and terminating its parser.

    Returns void | Promise<void>

  • Internal

    extension point for plugins that want to be notified when the test is about to end, whether explicitly or implicitly.

    If the function returns a Promise, it will be awaited before ending the TAP stream.

    Returns void | Promise<void>

  • Internal

    extension point for TestBase to know when a child tests is done being processed and it's safe to move on to the next one.

    Returns void

  • Internal

    Method called when an unrecoverable error is encountered in a test.

    Typically, in tests you would not call this, you'd just actually throw an error.

    Parameters

    • er: any
    • Optional extra: Extra
    • proxy: boolean = false

    Returns undefined | void | Extra

  • Internal

    Called when the test times out. Options are passed as diagnostics to the threw() method

    Parameters

    • options: Extra & {
          expired?: string;
      } = ...

    Returns void

  • Internal

    Await the end of a Promise before proceeding. The supplied callback is called with the Waiter object.

    This is internal, used in some plugins when a promise must be awaited before proceeding. In normal test usage, it's usually best to simply use an async test function and await promises as normal.

    Parameters

    • promise: Promise<any>
    • Optional cb: ((w) => any)
        • (w): any
        • Parameters

          Returns any

    • expectReject: boolean = false

    Returns Promise<void>

Subtest Methods

  • Parse stdin as the only tap stream (ie, not as a child test) If used, then no other subtests or assertions are allowed.

    Type Parameters

    Parameters

    • Optional extra: T & {
          tapStream?: Readable | Minipass<string | Buffer, ContiguousData, Events<string | Buffer>>;
      }

    Returns void

  • Internal

    Mount a subtest, using this Test object as a harness. Exposed so that it can be used by some builtin plugins, but perhaps the least convenient way imaginable to create subtests. Just use t.test() to do that, it's much easier.

    Type Parameters

    Parameters

    • Class: (new (options) => T)
        • new (options): T
        • Parameters

          • options: O

          Returns T

    • extra: TestBaseOpts | O = {}
    • caller: ((...a) => unknown) = ...
        • (...a): unknown
        • Parameters

          • Rest ...a: any[]

          Returns unknown

    Returns PromiseWithSubtest<T>

Test Lifecycle Management

jobs: number

The number of subtests to run in parallel, if allowed

  • immediately exit this and all parent tests with a TAP Bail out! message.

    Parameters

    • Optional message: string

    Returns void

  • Explicitly mark the test as completed, outputting the TAP plan line if needed.

    This is not required to be called if the test function returns a promise, or if a plan is explicitly declared and eventually fulfilled.

    Parameters

    Returns this

  • Specify the number of Test Points expected by this test. Outputs a TAP plan line.

    Parameters

    • n: number
    • Optional comment: string

    Returns void

  • Parameters

    • n: number
    • comment: string
    • implicit: typeof IMPLICIT

    Returns void

  • Set the amount of time in milliseconds before this test is considered a timeout. The time is counted from right now, so for example, repeatedly calling t.setTimeout(100) can keep it going indefinitely, as long as you call it more often than every 100ms.

    Calling setTimeout(0) will remove the timer and allow the test to run indefinitely.

    Parameters

    • n: number

    Returns void

Test Reflection

bailedOut: string | boolean

True if this test emitted a bailout

count: number = 0

The count of all assertions made directly on this test.

counts: Counts

The count of all assertions that this stream emitted

errors: TapError[]

Unrecoverable TAP protocol errors in the stream

hrtime: bigint

High resolution time in ns that this test took to complete.

lists: Lists

Lists of todo, skip, and failure test points. If passes: true is set in the options, then passing test points will also be tracked.

name: string

the name of this test

results?: FinalResults

Set on completion. The results of the test run.

Attached when the Test class is instantiated from a TestBase, as a reference to the final plugged-in Test instance. If TestBase is used directly (outside the context of a plugin) or during plugin setup time, this will be undefined, so watch out.

time: number

Amount of time in milliseconds that this test took to complete.

  • get printedOutput(): boolean
  • True if the test has printed some output of any kind

    Returns boolean

  • get started(): boolean
  • Returns true if this test has begun

    Returns boolean