TextDecoderStream ignores empty lines

[aheissenberger]

Describe the bug
controller.enque will remove empty chunks from stream
When using e.g. LineStream, all empty lines are removed from the stream.

Steps to Reproduce

import { LineStream, DelimiterStream } from "https://deno.land/std@0.127.0/streams/mod.ts"

const encoder = new TextEncoder();
const textStream = new ReadableStream({
    start(controller) {
        controller.enqueue(encoder.encode("Linie 1\n\nLine 3\n"));
        controller.close();
    },
});
let countLines = 0;
const lines = textStream
    .pipeThrough(new LineStream())
    .pipeThrough(new TextDecoderStream())
    .pipeThrough(new TransformStream({
        transform(chunk, controller) {
            countLines++
            console.log(`${countLines} LINE: "${chunk}" - ${chunk.length}`)
            controller.enqueue(chunk)
        }
    }))
    .pipeThrough(new TextEncoderStream())

const buf = [];
for await (const s of lines) {
    buf.push(s);
}

wrong result

1 LINE: "Linie 1" - 7
2 LINE: "Line 3" - 6

Expected behavior

empty Lines should not be suppressed

correct result

1 LINE: "Linie 1" - 7
2 LINE: ""- 0
3 LINE: "Line 3" - 6

Environment

• OS: MacOS 12.2.1
• deno version: deno 1.19.1 (release, aarch64-apple-darwin); v8 9.9.115.7; typescript 4.5.2
• std version: 0.127.0

[crowlKats]

upstream whatwg/encoding#283

[crowlKats]

This has been addressed in denoland/deno_std#1978. This problem will now not occur with TextLineStream.