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// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.import { assertEquals } from "../assert/mod.ts";import { StringWriter } from "./string_writer.ts";import { StringReader } from "./string_reader.ts";import { copyN } from "./copy_n.ts";import { copy } from "./copy.ts";
Deno.test("ioStringWriter", async function () {  const w = new StringWriter("base");  const r = new StringReader("0123456789");  await copyN(r, w, 4);  assertEquals(w.toString(), "base0123");  await copy(r, w);  assertEquals(w.toString(), "base0123456789");});
Deno.test("ioStringWriterSync", function () {  const encoder = new TextEncoder();  const w = new StringWriter("");  w.writeSync(encoder.encode("deno"));  assertEquals(w.toString(), "deno");  w.writeSync(encoder.encode("\nland"));  assertEquals(w.toString(), "deno\nland");});
Deno.test("ioStringWriterIsolationTest", async function () {  const encoder = new TextEncoder();  const src = "ABC";  const srcChunks = src.split("").map((c) => encoder.encode(c));
  const w = new StringWriter();  for (const c of srcChunks) {    const written = await w.write(c);    assertEquals(written, 1);  }  assertEquals(w.toString(), src);});