'use strict';
const nativePromisePrototype = (async () => {})().constructor.prototype;
const descriptors = ['then', 'catch', 'finally'].map(property => [
property,
Reflect.getOwnPropertyDescriptor(nativePromisePrototype, property)
]);
// The return value is a mixin of `childProcess` and `Promise`
const mergePromise = (spawned, promise) => {
for (const [property, descriptor] of descriptors) {
// Starting the main `promise` is deferred to avoid consuming streams
const value = typeof promise === 'function' ?
(...args) => Reflect.apply(descriptor.value, promise(), args) :
descriptor.value.bind(promise);
Reflect.defineProperty(spawned, property, {...descriptor, value});
}
return spawned;
};
// Use promises instead of `child_process` events
const getSpawnedPromise = spawned => {
return new Promise((resolve, reject) => {
spawned.on('exit', (exitCode, signal) => {
resolve({exitCode, signal});
});
spawned.on('error', error => {
reject(error);
});
if (spawned.stdin) {
spawned.stdin.on('error', error => {
reject(error);
});
}
});
};
module.exports = {
mergePromise,
getSpawnedPromise
};