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import { assertEquals } from "../assert/mod.ts";// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
import { iterateReader, iterateReaderSync } from "./iterate_reader.ts";import { readerFromIterable } from "./reader_from_iterable.ts";import { delay } from "../async/delay.ts";import type { Reader, ReaderSync } from "../io/types.ts";
Deno.test("iterateReader()", async () => {  // ref: https://github.com/denoland/deno/issues/2330  const encoder = new TextEncoder();
  class TestReader implements Reader {    #offset = 0;    #buf: Uint8Array;
    constructor(s: string) {      this.#buf = new Uint8Array(encoder.encode(s));    }
    read(p: Uint8Array): Promise<number | null> {      const n = Math.min(p.byteLength, this.#buf.byteLength - this.#offset);      p.set(this.#buf.slice(this.#offset, this.#offset + n));      this.#offset += n;
      if (n === 0) {        return Promise.resolve(null);      }
      return Promise.resolve(n);    }  }
  const reader = new TestReader("hello world!");
  let totalSize = 0;  await Array.fromAsync(    iterateReader(reader),    (buf) => totalSize += buf.byteLength,  );
  assertEquals(totalSize, 12);});
Deno.test("iterateReader() works with slow consumer", async () => {  const a = new Uint8Array([97]);  const b = new Uint8Array([98]);  const iter = iterateReader(readerFromIterable([a, b]));  const promises = [];  for await (const bytes of iter) {    promises.push(delay(10).then(() => bytes));  }  assertEquals([a, b], await Promise.all(promises));});
Deno.test("iterateReaderSync()", () => {  // ref: https://github.com/denoland/deno/issues/2330  const encoder = new TextEncoder();
  class TestReader implements ReaderSync {    #offset = 0;    #buf: Uint8Array;
    constructor(s: string) {      this.#buf = new Uint8Array(encoder.encode(s));    }
    readSync(p: Uint8Array): number | null {      const n = Math.min(p.byteLength, this.#buf.byteLength - this.#offset);      p.set(this.#buf.slice(this.#offset, this.#offset + n));      this.#offset += n;
      if (n === 0) {        return null;      }
      return n;    }  }
  const reader = new TestReader("hello world!");
  let totalSize = 0;  for (const buf of iterateReaderSync(reader)) {    totalSize += buf.byteLength;  }
  assertEquals(totalSize, 12);});
Deno.test("iterateReaderSync() works with slow consumer", async () => {  const a = new Uint8Array([97]);  const b = new Uint8Array([98]);  const data = [a, b];  const readerSync = {    readSync(u8: Uint8Array) {      const bytes = data.shift();      if (bytes) {        u8.set(bytes);        return bytes.length;      }      return null;    },  };  const iter = iterateReaderSync(readerSync);  const promises = [];  for (const bytes of iter) {    promises.push(delay(10).then(() => bytes));  }  assertEquals([a, b], await Promise.all(promises));});