Stage 4 Draft / October 9, 2024

Promise.try

1 Promise.try ( callbackfn, ...args )

When the try method is called with argument callbackfn, the following steps are taken:

  1. Let C be the this value.
  2. If C is not an Object, throw a TypeError exception.
  3. Let promiseCapability be ? NewPromiseCapability(C).
  4. Let status be Completion(Call(callbackfn, undefined, args)).
  5. If status is an abrupt completion, then
    1. Perform ? Call(promiseCapability.[[Reject]], undefined, « status.[[Value]] »).
  6. Else,
    1. Perform ? Call(promiseCapability.[[Resolve]], undefined, « status.[[Value]] »).
  7. Return promiseCapability.[[Promise]].
 Note

This function expects its this value to be a constructor function that supports the parameter conventions of the Promise constructor.

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© 2024 Jordan Harband

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