single-pipe.js

function pipe(source, dest, options) {
    if (!options) {
        options = {}
    }

    var close = "close" in options ? Boolean(options.close) : true

    pump()
    return dest

    function pump() {
        if (dest.writableState === "writable") {
            moveChunk()
        } else if (dest.writableState === "waiting") {
            dest.waitForWritable().then(pump)
        } else if (dest.writableState === "errored") {
            source.abort()
        } else if (dest.writableState === "closed") {
            // NO OP. Terminate pipe(). Do not close source
        }
    }

    function moveChunk() {
        if (source.readableState === "readable") {
            var chunk = source.read()
            dest.write(chunk)
            pump()
        } else if (source.readableState === "waiting") {
            source.waitForReadable().then(pump)
        } else if (source.readableState === "finished") {
            if (close) {
                dest.close()
            }
        } else if (source.readableState === "errored") {
            dest.dispose()
        }
    }
}