it-pushable

it-pushable

An iterable that you can push values into

Install

npm install it-pushable

Usage

const pushable = require('it-pushable')
const source = pushable()

setTimeout(() => source.push('hello'), 100)
setTimeout(() => source.push('world'), 200)
setTimeout(() => source.end(), 300)

const start = Date.now()

for await (const value of source) {
  console.log(`got "${value}" after ${Date.now() - start}ms`)
}
console.log(`done after ${Date.now() - start}ms`)

/*
Output:
got "hello" after 105ms
got "world" after 207ms
done after 309ms
*/

API

pushable([options])

Create a new async iterable. The values yielded from calls to .next() or when used in a for await of loop are "pushed" into the iterable. Returns an async iterable object with the following additional methods:

• .push(value) - push a value into the iterable. Values are yielded from the iterable in the order they are pushed. Values not yet consumed from the iterable are buffered
• .end([err]) - end the iterable after all values in the buffer (if any) have been yielded. If an error is passed the buffer is cleared immediately and the next iteration will throw the passed error

options is an optional parameter, an object with the following properties:

• onEnd - a function called after all values have been yielded from the iterator (including buffered values). In the case when the iterator is ended with an error it will be passed the error as a parameter.
• writev - a boolean used to signal that the consumer of this iterable supports processing multiple buffered chunks at a time. When this option is set to true values yielded from the iterable will be arrays.

Note: the onEnd function may be passed instead of options.

Related

• it-pipe Utility to "pipe" async iterables together

Contribute

Feel free to dive in! Open an issue or submit PRs.

License

MIT © Alan Shaw