Add TextEncoder/TextDecoder

Fixes #470

This commit increases exe size
out/release/deno  48M -> 52M

js/globals.ts

@@ -1,5 +1,7 @@
 // Copyright 2018 the Deno authors. All rights reserved. MIT license.
-
+// tslint:disable-next-line:no-reference
+/// <reference path="./text_encoding.d.ts" />
+import * as te from "text-encoding";
 import { Console } from "./console";
 
 declare global {
@@ -18,6 +20,18 @@ declare global {
   const console: Console;
   const deno: Readonly<Deno>;
   const window: Window;
+
+  // tslint:disable-next-line:variable-name
+  let TextDecoder: {
+    prototype: TextDecoder;
+    new (label?: string, options?: TextDecoderOptions): TextDecoder;
+  };
+
+  // tslint:disable-next-line:variable-name
+  let TextEncoder: {
+    prototype: TextEncoder;
+    new (): TextEncoder;
+  };
 }
 
 // If you use the eval function indirectly, by invoking it via a reference
@@ -50,11 +64,9 @@ window["window"] = window; // Create a window object.
 // window["clearTimeout"] = timer.clearTimer;
 // window["clearInterval"] = timer.clearTimer;
 
-window["console"] = new Console(libdeno.print);
+window.console = new Console(libdeno.print);
+window.TextEncoder = te.TextEncoder;
+window.TextDecoder = te.TextDecoder;
 
 // import { fetch } from "./fetch";
 // window["fetch"] = fetch;
-
-// import { TextEncoder, TextDecoder } from "text-encoding";
-// window["TextEncoder"] = TextEncoder;
-// window["TextDecoder"] = TextDecoder;

js/text_encoding.d.ts

@@ -0,0 +1,69 @@
+// Copyright 2018 the Deno authors. All rights reserved. MIT license.
+// In order to avoid importing all of lib.dom.d.ts we include type defintiions
+// for text-encoding polyfill below. Ideally we could use @types/text-encoding
+// but it depends on lib.dom.d.ts.
+// https://github.com/DefinitelyTyped/DefinitelyTyped/commit/f9a3f3c2da18980f7c5b089eb6d298dc0fd3797b#r30007625
+
+type BufferSource = ArrayBufferView | ArrayBuffer;
+
+interface TextDecodeOptions {
+  stream?: boolean;
+}
+
+interface TextDecoderOptions {
+  fatal?: boolean;
+  ignoreBOM?: boolean;
+}
+
+interface TextDecoder {
+  /**
+   * Returns encoding's name, lowercased.
+   */
+  readonly encoding: string;
+  /**
+   * Returns true if error mode is "fatal", and false
+   * otherwise.
+   */
+  readonly fatal: boolean;
+  /**
+   * Returns true if ignore BOM flag is set, and false otherwise.
+   */
+  readonly ignoreBOM: boolean;
+  /**
+   * Returns the result of running encoding's decoder. The
+   * method can be invoked zero or more times with options's stream set to
+   * true, and then once without options's stream (or set to false), to process
+   * a fragmented stream. If the invocation without options's stream (or set to
+   * false) has no input, it's clearest to omit both arguments.
+   * var string = "", decoder = new TextDecoder(encoding), buffer;
+   * while(buffer = next_chunk()) {
+   * string += decoder.decode(buffer, {stream:true});
+   * }
+   * string += decoder.decode(); // end-of-stream
+   * If the error mode is "fatal" and encoding's decoder returns error, throws a TypeError.
+   */
+  decode(input?: BufferSource, options?: TextDecodeOptions): string;
+}
+
+interface TextEncoder {
+  /**
+   * Returns "utf-8".
+   */
+  readonly encoding: string;
+  /**
+   * Returns the result of running UTF-8's encoder.
+   */
+  encode(input?: string): Uint8Array;
+}
+
+declare module "text-encoding" {
+  export let TextDecoder: {
+    prototype: TextDecoder;
+    new (label?: string, options?: TextDecoderOptions): TextDecoder;
+  };
+
+  export let TextEncoder: {
+    prototype: TextEncoder;
+    new (): TextEncoder;
+  };
+}

package.json

@@ -16,6 +16,7 @@
     "rollup-plugin-typescript2": "^0.16.1",
     "rollup-pluginutils": "^2.3.0",
     "source-map-support": "^0.5.6",
+    "text-encoding": "^0.6.4",
     "tslint": "^5.10.0",
     "tslint-eslint-rules": "^5.3.1",
     "tslint-no-circular-imports": "^0.5.0",

tests/read_file_sync.ts

@@ -9,7 +9,9 @@ if (!data.byteLength) {
     `Expected positive value for data.byteLength ${data.byteLength}`
   );
 }
-const pkg = JSON.parse(String.fromCharCode(...data));
+const decoder = new TextDecoder("utf-8");
+const json = decoder.decode(data);
+const pkg = JSON.parse(json);
 if (pkg['devDependencies'] == null) {
   throw Error("Expected a positive number of devDependencies");
 }