Adds synchronous state inspection to the native promise
Provides a function of the form:
<R>(p: Promise<R>) => PromiseWithState<R>The returned stateful promise is the same object as the provided promise, with the following additional properties:
#resolved : boolean#rejected : boolean#complete : boolean
Useful for testing without introducting a mock for Promise. As such it is minorly limited; see caveats
import assert from 'console';
import seePromiseState from 'see-promise-state';
const indefinite = seePromiseState(new Promise(() => {}));
assert(indefinite.complete === false);
assert(indefinite.resolved === false);
assert(indefinite.rejected === false);
const immediateResolution = seePromiseState(Promise.resolve());
assert(immediateResolution.complete === true);
assert(immediateResolution.resolved === true);
assert(immediateResolution.rejected === false);
const immediateRejection = seePromiseState(Promise.reject());
assert(immediateRejection.complete === true);
assert(immediateRejection.resolved === false);
assert(immediateRejection.rejected === true);Does not immediately apply to immediately resolving promises:
seePromiseState(Promise.resolve()).complete
// false
x = seePromiseState(Promise.resolve())
await sleep(0);
x.complete
// trueMay not be correct for chains started before conversion
x = asyncTask();
x.then(() => console.log('A: ' + x.complete));
seePromiseState(x);
x.then(() => console.log('B: ' + x.complete));
await x;
// > 'A: false'
// > 'B: true'Feel free to make any contributions
The project uses yarn berry with zero-installs.
Build with: yarn build
Test with: yarn test
If you use vscode, running yarn setupVSCode will setup vscode's typescript with yarn pnp.
If you use vscode launch configs are included for testing.