test: enable idlharness tests for encoding

TextDecoderStream and TextEncoderStream are now exposed as globals,
so we can run the entire Encoding idlharness test suite.

PR-URL: https://github.com/nodejs/node/pull/50778
Reviewed-By: Filip Skokan <panva.ip@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

test/common/wpt.js

@@ -617,7 +617,7 @@ class WPTRunner {
       'ReadableStreamBYOBReader', 'ReadableStreamBYOBRequest',
       'ReadableByteStreamController', 'ReadableStreamDefaultController',
       'ByteLengthQueuingStrategy', 'CountQueuingStrategy',
-      'TextEncoderStream', 'TextDecoderStream',
+      'TextEncoder', 'TextDecoder', 'TextEncoderStream', 'TextDecoderStream',
       'CompressionStream', 'DecompressionStream',
     ];
     if (Boolean(process.versions.openssl) && !process.env.NODE_SKIP_CRYPTO) {

test/wpt/status/encoding.json

@@ -37,7 +37,7 @@
     "skip": "The iso-8859-16 encoding is not supported"
   },
   "idlharness.any.js": {
-    "skip": "No implementation of TextDecoderStream and TextEncoderStream"
+    "requires": ["small-icu"]
   },
   "idlharness-shadowrealm.window.js": {
     "skip": "ShadowRealm support is not enabled"

test/wpt/test-encoding.js

@@ -3,4 +3,6 @@
 const { WPTRunner } = require('../common/wpt');
 const runner = new WPTRunner('encoding');
 
+runner.pretendGlobalThisAs('Window');
+
 runner.runJsTests();