setup-python/node_modules/merge-stream/README.md

merge-stream

Merge (interleave) a bunch of streams.

Synopsis

var stream1 = new Stream();
var stream2 = new Stream();

var merged = mergeStream(stream1, stream2);

var stream3 = new Stream();
merged.add(stream3);
merged.isEmpty();
//=> false

Description

This is adapted from event-stream separated into a new module, using Streams3.

API

mergeStream

Type: function

Merges an arbitrary number of streams. Returns a merged stream.

merged.add

A method to dynamically add more sources to the stream. The argument supplied to add can be either a source or an array of sources.

merged.isEmpty

A method that tells you if the merged stream is empty.

When a stream is "empty" (aka. no sources were added), it could not be returned to a gulp task.

So, we could do something like this:

stream = require('merge-stream')();
// Something like a loop to add some streams to the merge stream
// stream.add(streamA);
// stream.add(streamB);
return stream.isEmpty() ? null : stream;

License

MIT