(Anonymous)

Cancels a task execution. Does nothing if the task has already been resolved.

Example:

const { task } = require('folktale/concurrency/task');

let message = 'world';
const helloIn50 = task(
  resolver => {
    const timerId = setTimeout(() => {
      message = 'hello';
      resolver.resolve();
    }, 50);
    resolver.cleanup(() => clearTimeout(timerId));
  }
);

const execution = helloIn50.run();
execution.cancel();
try {
  const result = await execution.promise();
  throw 'never happens';
} catch (error) {
  $ASSERT(message == 'world');
}