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// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
import { assert, assertEquals } from "../testing/asserts.ts";import {  readableStreamFromIterable,  readerFromIterable,  readerFromStreamReader,  writableStreamFromWriter,  writerFromStreamWriter,} from "./streams.ts";
function repeat(c: string, bytes: number): Uint8Array {  assertEquals(c.length, 1);  const ui8 = new Uint8Array(bytes);  ui8.fill(c.charCodeAt(0));  return ui8;}
Deno.test("[io] readerFromIterable()", async function () {  const reader = readerFromIterable((function* () {    const encoder = new TextEncoder();    for (const string of ["hello", "deno", "foo"]) {      yield encoder.encode(string);    }  })());
  const readStrings = [];  const decoder = new TextDecoder();  const p = new Uint8Array(4);  while (true) {    const n = await reader.read(p);    if (n == null) {      break;    }    readStrings.push(decoder.decode(p.slice(0, n)));  }  assertEquals(readStrings, ["hell", "o", "deno", "foo"]);});
Deno.test("[io] writerFromStreamWriter()", async function () {  const written: string[] = [];  const chunks: string[] = ["hello", "deno", "land"];  const writableStream = new WritableStream({    write(chunk): void {      const decoder = new TextDecoder();      written.push(decoder.decode(chunk));    },  });
  const encoder = new TextEncoder();  const writer = writerFromStreamWriter(writableStream.getWriter());
  for (const chunk of chunks) {    const n = await writer.write(encoder.encode(chunk));    // stream writers always write all the bytes    assertEquals(n, chunk.length);  }
  assertEquals(written, chunks);});
Deno.test("[io] readerFromStreamReader()", async function () {  const chunks: string[] = ["hello", "deno", "land"];  const expected = chunks.slice();  const readChunks: Uint8Array[] = [];  const readableStream = new ReadableStream({    pull(controller): void {      const encoder = new TextEncoder();      const chunk = chunks.shift();      if (!chunk) return controller.close();      controller.enqueue(encoder.encode(chunk));    },  });
  const decoder = new TextDecoder();  const reader = readerFromStreamReader(readableStream.getReader());
  let i = 0;
  while (true) {    const b = new Uint8Array(1024);    const n = await reader.read(b);
    if (n === null) break;
    readChunks.push(b.subarray(0, n));    assert(i < expected.length);
    i++;  }
  assertEquals(    expected,    readChunks.map((chunk) => decoder.decode(chunk)),  );});
Deno.test("[io] readerFromStreamReader() big chunks", async function () {  const bufSize = 1024;  const chunkSize = 3 * bufSize;  const writer = new Deno.Buffer();
  // A readable stream can enqueue chunks bigger than Copy bufSize  // Reader returned by toReader should enqueue exceeding bytes  const chunks: string[] = [    "a".repeat(chunkSize),    "b".repeat(chunkSize),    "c".repeat(chunkSize),  ];  const expected = chunks.slice();  const readableStream = new ReadableStream({    pull(controller): void {      const encoder = new TextEncoder();      const chunk = chunks.shift();      if (!chunk) return controller.close();
      controller.enqueue(encoder.encode(chunk));    },  });
  const reader = readerFromStreamReader(readableStream.getReader());  const n = await Deno.copy(reader, writer, { bufSize });
  const expectedWritten = chunkSize * expected.length;  assertEquals(n, chunkSize * expected.length);  assertEquals(writer.length, expectedWritten);});
Deno.test("[io] readerFromStreamReader() irregular chunks", async function () {  const bufSize = 1024;  const chunkSize = 3 * bufSize;  const writer = new Deno.Buffer();
  // A readable stream can enqueue chunks bigger than Copy bufSize  // Reader returned by toReader should enqueue exceeding bytes  const chunks: Uint8Array[] = [    repeat("a", chunkSize),    repeat("b", chunkSize + 253),    repeat("c", chunkSize + 8),  ];  const expected = new Uint8Array(    chunks      .slice()      .map((chunk) => [...chunk])      .flat(),  );  const readableStream = new ReadableStream({    pull(controller): void {      const chunk = chunks.shift();      if (!chunk) return controller.close();
      controller.enqueue(chunk);    },  });
  const reader = readerFromStreamReader(readableStream.getReader());
  const n = await Deno.copy(reader, writer, { bufSize });  assertEquals(n, expected.length);  assertEquals(expected, writer.bytes());});
Deno.test("[io] writableStreamFromWriter()", async function () {  const written: string[] = [];  const chunks: string[] = ["hello", "deno", "land"];  const decoder = new TextDecoder();
  // deno-lint-ignore require-await  async function write(p: Uint8Array): Promise<number> {    written.push(decoder.decode(p));    return p.length;  }
  const writableStream = writableStreamFromWriter({ write });
  const encoder = new TextEncoder();  const streamWriter = writableStream.getWriter();  for (const chunk of chunks) {    await streamWriter.write(encoder.encode(chunk));  }
  assertEquals(written, chunks);});
Deno.test("[io] readableStreamFromIterable() array", async function () {  const strings: string[] = ["hello", "deno", "land"];  const encoder = new TextEncoder();  const readableStream = readableStreamFromIterable(    strings.map((s) => encoder.encode(s)),  );
  const readStrings = [];  const decoder = new TextDecoder();  for await (const chunk of readableStream) {    readStrings.push(decoder.decode(chunk));  }
  assertEquals(readStrings, strings);});
Deno.test("[io] readableStreamFromIterable() generator", async function () {  const strings: string[] = ["hello", "deno", "land"];  const readableStream = readableStreamFromIterable((function* () {    const encoder = new TextEncoder();    for (const string of strings) {      yield encoder.encode(string);    }  })());
  const readStrings = [];  const decoder = new TextDecoder();  for await (const chunk of readableStream) {    readStrings.push(decoder.decode(chunk));  }
  assertEquals(readStrings, strings);});