FuturableTask.reject()

Create a task that immediately fails with an error.

Syntax

FuturableTask.reject<T = never>(reason: any): FuturableTask<T>

Parameters

reason

The error or reason for rejection.

Return Value

A FuturableTask<T> that fails with the provided reason.

Description

Creates a task that immediately fails when executed. Useful for error handling chains, testing, or representing known error states.

Examples

Basic Usage

const task = FuturableTask.reject(new Error('Failed'));

try {
  await task.run();
} catch (error) {
  console.log(error.message); // "Failed"
}

Error Handling Chain

const task = FuturableTask
  .reject(new Error('Primary failed'))
  .fallbackTo(() => fallbackValue);

const result = await task.run(); // fallbackValue

Conditional Errors

const validateTask = (data: any) =>
  data.valid
    ? FuturableTask.resolve(data)
    : FuturableTask.reject(new Error('Invalid data'));

Testing Error Paths

// Test error handling in your application
const mockError = FuturableTask.reject(
  new Error('Network error')
);

const result = await mockError.runSafe();
expect(result.success).toBe(false);

With orElse

const task = FuturableTask
  .reject(new Error('First attempt'))
  .orElse(() => FuturableTask.of(() => secondAttempt()))
  .orElse(() => FuturableTask.resolve(defaultValue));

See Also

• resolve() - Create a successful task
• fallbackTo() - Handle errors
• orElse() - Alternative tasks