promise-run
v1.0.0
Published
Promise runner for composing 'thenable' objects (or callbacks) in series and/or parallel sequences with labelled return values.
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pete_bReadme
Promise runner for composing 'thenable' objects (or callbacks) in series and/or parallel sequences with labelled return values.
Initially motivated by the complications of using Promise.all() and maintaining readable code.
To execute some Promises in parallel pass a plain object to exec(). Under the hood Promise.all() is being invoked but here the result is an object with the values keyed as per the input:
PromiseRun.exec({
foo: fetch('http://foo.com'),
bar: fetch('http://bar.com'),
baz: fetch('http://baz.com'),
})
.then(function (values) {
// values:
// {
// foo: <HTML>,
// bar: <HTML>,
// baz: <HTML>,
// }
})To execute some Promises sequentially in series pass an array to exec():
PromiseRun.exec([
Promise.resolve('first'),
Promise.resolve('second'),
function (resolve, reject) {
resolve('third')
}
])
.then(function (values) {
// values:
// {
// '0': 'first',
// '1': 'second',
// '2': 'third',
// }
})Any combination of series or parallel execution can be composed by passing plain objects or arrays. Here the series arguments are given labels by using a [label, thenable] format:
PromiseRun.exec([
['first', Promise.resolve('first')],
['parallel fetch', {
foo: function (resolve, reject) {
// async op...
resolve('foo');
},
bar: function (resolve, reject) {
// async op...
resolve('bar');
},
baz: function (resolve, reject) {
// async op...
resolve('baz');
}
}],
['and finally', Promise.resolve('all done')],
])
.then(function (values) {
// values:
// {
// first: 'first',
// 'parallel fetch': {
// foo: 'foo',
// bar: 'bar',
// baz: 'baz',
// },
// 'and finally': 'all done',
// }
})