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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.import { createReadStream, ReadStream } from "./_fs_streams.ts";import * as path from "../../path/mod.ts";import { assertEquals } from "../../testing/asserts.ts";import { Buffer } from "../buffer.ts";
const moduleDir = path.dirname(path.fromFileUrl(import.meta.url));const testData = path.resolve(moduleDir, "testdata", "hello.txt");
// Need to wait for file processing to complete within each test to prevent false negatives.async function waiter(readable: ReadStream, interval = 100, maxCount = 50) {  for (let i = maxCount; i > 0; i--) {    await new Promise((resolve) => setTimeout(resolve, interval));    if (readable.destroyed) return true;  }  return false;}
Deno.test({  name: "[node/fs.ReadStream] Read a chunk of data using 'new ReadStream()'",  async fn() {    // deno-lint-ignore ban-ts-comment    // @ts-ignore    const readable = new ReadStream(testData);
    let data: Uint8Array;    readable.on("data", (chunk: Uint8Array) => {      data = chunk;    });
    readable.on("close", () => {      assertEquals(new TextDecoder().decode(data as Uint8Array), "hello world");    });
    assertEquals(await waiter(readable), true);  },});
Deno.test({  name:    "[node/fs.createReadStream] Read a chunk of data using 'new createReadStream()'",  async fn() {    // deno-lint-ignore ban-ts-comment    // @ts-ignore    const readable = new createReadStream(testData);
    let data: Uint8Array;    readable.on("data", (chunk: Uint8Array) => {      data = chunk;    });
    readable.on("close", () => {      assertEquals(new TextDecoder().decode(data as Uint8Array), "hello world");    });
    assertEquals(await waiter(readable), true);  },});
Deno.test({  name: "[node/fs.createReadStream] Read given amount of data",  async fn() {    const readable = createReadStream(testData);
    const data: (Uint8Array | null)[] = [];    readable.on("readable", function () {      data.push(readable.read(5));      data.push(readable.read());    });
    readable.on("close", () => {      assertEquals(new TextDecoder().decode(data[0] as Uint8Array), "hello");      assertEquals(new TextDecoder().decode(data[1] as Uint8Array), " world");      assertEquals(data[2], null);    });
    assertEquals(await waiter(readable), true);  },});
Deno.test({  name: "[node/fs.createReadStream] Handling of read position",  async fn() {    const readable = createReadStream(testData, {      highWaterMark: 3,      start: 1,      end: 9,    });
    const data: (Uint8Array | null)[] = [];    readable.on("readable", function () {      data.push(readable.read(4));      data.push(readable.read(1));    });
    readable.on("close", () => {      assertEquals(data[0], null);      assertEquals(new TextDecoder().decode(data[1] as Uint8Array), "e");      assertEquals(new TextDecoder().decode(data[2] as Uint8Array), "llo ");      assertEquals(new TextDecoder().decode(data[3] as Uint8Array), "w");      assertEquals(new TextDecoder().decode(data[4] as Uint8Array), "orl");      assertEquals(data[5], null);    });
    assertEquals(await waiter(readable), true);  },});
Deno.test({  name: "[node/fs.createReadStream] Specify the path as a Buffer",  async fn() {    const readable = createReadStream(Buffer.from(testData));
    let data: Uint8Array;    readable.on("data", (chunk: Uint8Array) => {      data = chunk;    });
    readable.on("close", () => {      assertEquals(new TextDecoder().decode(data as Uint8Array), "hello world");    });
    assertEquals(await waiter(readable), true);  },});
Deno.test({  name: "[node/fs.createReadStream] Destroy the stream with an error",  async fn() {    const readable = createReadStream(testData);
    const data: (Uint8Array | null)[] = [];    readable.on("readable", function () {      data.push(readable.read(5));      readable.destroy(Error("destroy has been called."));    });
    readable.on("close", () => {      assertEquals(new TextDecoder().decode(data[0] as Uint8Array), "hello");      assertEquals(data.length, 1);    });
    readable.on("error", (err: Error) => {      assertEquals(err.name, "Error");      assertEquals(err.message, "destroy has been called.");    });
    assertEquals(await waiter(readable), true);  },});