Class Task<TResult, TProgress>

Represents a Promise that supports progress reporting and cancellation.

ProgressablePromise extends the standard Promise pattern by allowing consumers to:

  • Subscribe to progress updates via an event emitter.
  • Cancel the underlying asynchronous operation using a cancellation token.
  • Chain with then, catch, and finally methods, returning a new ProgressablePromise.

Example

const progressable = new ProgressablePromise<number>((progress, token) => {
  return new Promise<number>((resolve, reject) => {
    let count = 0;
    const interval = setInterval(() => {
      if (token?.isCancellationRequested) {
        clearInterval(interval);
        reject(new Error('Cancelled'));
        return;
      }
      progress?.(++count);
      if (count === 10) {
        clearInterval(interval);
        resolve(count);
      }
    }, 100);
  });
});

progressable.on('progress', (value) => console.log('Progress:', value));

Type Parameters

  • TResult

    The type of the resolved value of the promise.

  • TProgress = unknown

    The type of the progress update values (defaults to TResult).

Hierarchy

  • Task

Implements

Constructors

constructor

Properties

[toStringTag] cancellationTokenSource events taskPromise taskStatus

Accessors

hasError isFinished isRunning

Methods

cancel catch finally on then

Constructors

constructor

  • Type Parameters

    • TResult

    • TProgress = unknown

    Parameters

    • task: ((progress?, cancellationToken?) => Promise<TResult>)
        • (progress?, cancellationToken?): Promise<TResult>

        • Parameters

          Returns Promise<TResult>

    Returns Task<TResult, TProgress>

Properties

Readonly [toStringTag]

[toStringTag]: "Task<T>" = 'Task<T>'

Private cancellationTokenSource

cancellationTokenSource: CancellationTokenSource = ...

Private events

events: EventEmitter<DefaultEventMap> = ...

Private taskPromise

taskPromise: Promise<unknown>

Private taskStatus

taskStatus: TaskStatus = TaskStatus.executing

Accessors

hasError

isFinished

isRunning

Methods

cancel

catch

  • Attaches a callback for only the rejection of the Promise.

    Type Parameters

    • TResult1 = never

    Parameters

    • Optional onrejected: null | ((reason) => TResult1 | PromiseLike<TResult1>)

      The callback to execute when the Promise is rejected.

    Returns Task<TResult1, TProgress>

    A Promise for the completion of the callback.

finally

  • Attaches a callback that is invoked when the Promise is settled (fulfilled or rejected). The resolved value cannot be modified from the callback.

    Parameters

    • Optional onfinally: null | (() => void)

      The callback to execute when the Promise is settled (fulfilled or rejected).

    Returns Task<TResult, TProgress>

    A Promise for the completion of the callback.

on

  • Type Parameters

    • K extends keyof TaskEvents<TResult, TProgress>

    Parameters

    • event: K
    • listener: ((...args) => void)
        • (...args): void

        • Parameters

          • Rest ...args: TaskEvents<TResult, TProgress>[K]

          Returns void

    Returns Task<TResult, TProgress>

then

  • Attaches callbacks for the resolution and/or rejection of the Promise.

    Type Parameters

    • TResult1 = TResult

    • TResult2 = never

    Parameters

    • Optional onfulfilled: null | ((value) => TResult1 | PromiseLike<TResult1>)

      The callback to execute when the Promise is resolved.

    • Optional onrejected: null | ((reason) => TResult2 | PromiseLike<TResult2>)

      The callback to execute when the Promise is rejected.

    Returns Task<TResult1 | TResult2, TProgress>

    A Promise for the completion of which ever callback is executed.

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