test: split test-whatwg-encoding-textdecoder.js

Split test-whatwg-encoding-textdecoder.js into:

- `test-whatwg-encoding-custom-textdecoder.js` which tests
  Node.js-specific behaviors
- `test-whatwg-encoding-custom-textdecoder-api-invalid-label.js` which
  is a customized version of the WPT counterpart
- `test-whatwg-encoding-custom-api-basics.js` which is the part of
  `test-whatwg-encoding-api-basics.js` that can be run without ICU
- `test-whatwg-encoding-api-basics.js` which can be replaced with WPT
  later.

PR-URL: https://github.com/nodejs/node/pull/25155
Reviewed-By: James M Snell <jasnell@gmail.com>

4 files changed, 178 insertions, 102 deletions

diff --git a/test/parallel/test-whatwg-encoding-api-basics.js b/test/parallel/test-whatwg-encoding-api-basics.js
new file mode 100644
index 0000000000..8abaee8171
--- /dev/null
+++ b/test/parallel/test-whatwg-encoding-api-basics.js
@@ -0,0 +1,74 @@
+'use strict';
+
+// From: https://github.com/w3c/web-platform-tests/blob/master/encoding/api-basics.html
+// TODO(joyeecheung): replace this with WPT
+
+const common = require('../common');
+
+if (!common.hasIntl)
+  common.skip('missing Intl');
+
+const assert = require('assert');
+
+function testDecodeSample(encoding, string, bytes) {
+  assert.strictEqual(
+    new TextDecoder(encoding).decode(new Uint8Array(bytes)),
+    string);
+  assert.strictEqual(
+    new TextDecoder(encoding).decode(new Uint8Array(bytes).buffer),
+    string);
+}
+
+// `z` (ASCII U+007A), cent (Latin-1 U+00A2), CJK water (BMP U+6C34),
+// G-Clef (non-BMP U+1D11E), PUA (BMP U+F8FF), PUA (non-BMP U+10FFFD)
+// byte-swapped BOM (non-character U+FFFE)
+const sample = 'z\xA2\u6C34\uD834\uDD1E\uF8FF\uDBFF\uDFFD\uFFFE';
+
+{
+  const encoding = 'utf-8';
+  const string = sample;
+  const bytes = [
+    0x7A, 0xC2, 0xA2, 0xE6, 0xB0, 0xB4,
+    0xF0, 0x9D, 0x84, 0x9E, 0xEF, 0xA3,
+    0xBF, 0xF4, 0x8F, 0xBF, 0xBD, 0xEF,
+    0xBF, 0xBE
+  ];
+  const encoded = new TextEncoder().encode(string);
+  assert.deepStrictEqual([].slice.call(encoded), bytes);
+  assert.strictEqual(
+    new TextDecoder(encoding).decode(new Uint8Array(bytes)),
+    string);
+  assert.strictEqual(
+    new TextDecoder(encoding).decode(new Uint8Array(bytes).buffer),
+    string);
+}
+
+testDecodeSample(
+  'utf-16le',
+  sample,
+  [
+    0x7A, 0x00, 0xA2, 0x00, 0x34, 0x6C,
+    0x34, 0xD8, 0x1E, 0xDD, 0xFF, 0xF8,
+    0xFF, 0xDB, 0xFD, 0xDF, 0xFE, 0xFF
+  ]
+);
+
+testDecodeSample(
+  'utf-16be',
+  sample,
+  [
+    0x00, 0x7A, 0x00, 0xA2, 0x6C, 0x34,
+    0xD8, 0x34, 0xDD, 0x1E, 0xF8, 0xFF,
+    0xDB, 0xFF, 0xDF, 0xFD, 0xFF, 0xFE
+  ]
+);
+
+testDecodeSample(
+  'utf-16',
+  sample,
+  [
+    0x7A, 0x00, 0xA2, 0x00, 0x34, 0x6C,
+    0x34, 0xD8, 0x1E, 0xDD, 0xFF, 0xF8,
+    0xFF, 0xDB, 0xFD, 0xDF, 0xFE, 0xFF
+  ]
+);
diff --git a/test/parallel/test-whatwg-encoding-custom-api-basics.js b/test/parallel/test-whatwg-encoding-custom-api-basics.js
new file mode 100644
index 0000000000..c39bce5d74
--- /dev/null
+++ b/test/parallel/test-whatwg-encoding-custom-api-basics.js
@@ -0,0 +1,61 @@
+'use strict';
+
+// From: https://github.com/w3c/web-platform-tests/blob/master/encoding/api-basics.html
+// This is the part that can be run without ICU
+
+require('../common');
+
+const assert = require('assert');
+
+function testDecodeSample(encoding, string, bytes) {
+  assert.strictEqual(
+    new TextDecoder(encoding).decode(new Uint8Array(bytes)),
+    string);
+  assert.strictEqual(
+    new TextDecoder(encoding).decode(new Uint8Array(bytes).buffer),
+    string);
+}
+
+// `z` (ASCII U+007A), cent (Latin-1 U+00A2), CJK water (BMP U+6C34),
+// G-Clef (non-BMP U+1D11E), PUA (BMP U+F8FF), PUA (non-BMP U+10FFFD)
+// byte-swapped BOM (non-character U+FFFE)
+const sample = 'z\xA2\u6C34\uD834\uDD1E\uF8FF\uDBFF\uDFFD\uFFFE';
+
+{
+  const encoding = 'utf-8';
+  const string = sample;
+  const bytes = [
+    0x7A, 0xC2, 0xA2, 0xE6, 0xB0, 0xB4,
+    0xF0, 0x9D, 0x84, 0x9E, 0xEF, 0xA3,
+    0xBF, 0xF4, 0x8F, 0xBF, 0xBD, 0xEF,
+    0xBF, 0xBE
+  ];
+  const encoded = new TextEncoder().encode(string);
+  assert.deepStrictEqual([].slice.call(encoded), bytes);
+  assert.strictEqual(
+    new TextDecoder(encoding).decode(new Uint8Array(bytes)),
+    string);
+  assert.strictEqual(
+    new TextDecoder(encoding).decode(new Uint8Array(bytes).buffer),
+    string);
+}
+
+testDecodeSample(
+  'utf-16le',
+  sample,
+  [
+    0x7A, 0x00, 0xA2, 0x00, 0x34, 0x6C,
+    0x34, 0xD8, 0x1E, 0xDD, 0xFF, 0xF8,
+    0xFF, 0xDB, 0xFD, 0xDF, 0xFE, 0xFF
+  ]
+);
+
+testDecodeSample(
+  'utf-16',
+  sample,
+  [
+    0x7A, 0x00, 0xA2, 0x00, 0x34, 0x6C,
+    0x34, 0xD8, 0x1E, 0xDD, 0xFF, 0xF8,
+    0xFF, 0xDB, 0xFD, 0xDF, 0xFE, 0xFF
+  ]
+);
diff --git a/test/parallel/test-whatwg-encoding-custom-textdecoder-api-invalid-label.js b/test/parallel/test-whatwg-encoding-custom-textdecoder-api-invalid-label.js
new file mode 100644
index 0000000000..aabd3fe5c4
--- /dev/null
+++ b/test/parallel/test-whatwg-encoding-custom-textdecoder-api-invalid-label.js
@@ -0,0 +1,40 @@
+'use strict';
+// From: https://github.com/w3c/web-platform-tests/blob/master/encoding/api-invalid-label.html
+// With the twist that we specifically test for Node.js error codes
+
+const common = require('../common');
+
+[
+  'utf-8',
+  'unicode-1-1-utf-8',
+  'utf8',
+  'utf-16be',
+  'utf-16le',
+  'utf-16'
+].forEach((i) => {
+  ['\u0000', '\u000b', '\u00a0', '\u2028', '\u2029'].forEach((ws) => {
+    common.expectsError(
+      () => new TextDecoder(`${ws}${i}`),
+      {
+        code: 'ERR_ENCODING_NOT_SUPPORTED',
+        type: RangeError
+      }
+    );
+
+    common.expectsError(
+      () => new TextDecoder(`${i}${ws}`),
+      {
+        code: 'ERR_ENCODING_NOT_SUPPORTED',
+        type: RangeError
+      }
+    );
+
+    common.expectsError(
+      () => new TextDecoder(`${ws}${i}${ws}`),
+      {
+        code: 'ERR_ENCODING_NOT_SUPPORTED',
+        type: RangeError
+      }
+    );
+  });
+});
diff --git a/test/parallel/test-whatwg-encoding-textdecoder.js b/test/parallel/test-whatwg-encoding-custom-textdecoder.js
index 55afd34a02..ceee5b9cbb 100644
--- a/test/parallel/test-whatwg-encoding-textdecoder.js
+++ b/test/parallel/test-whatwg-encoding-custom-textdecoder.js
@@ -1,4 +1,7 @@
 // Flags: --expose-internals
+
+// This tests Node.js-specific behaviors of TextDecoder
+
 'use strict';
 
 const common = require('../common');
@@ -167,72 +170,6 @@ if (common.hasIntl) {
   });
 }
 
-// From: https://github.com/w3c/web-platform-tests/blob/master/encoding/api-basics.html
-function testDecodeSample(encoding, string, bytes) {
-  assert.strictEqual(
-    new TextDecoder(encoding).decode(new Uint8Array(bytes)),
-    string);
-  assert.strictEqual(
-    new TextDecoder(encoding).decode(new Uint8Array(bytes).buffer),
-    string);
-}
-
-// `z` (ASCII U+007A), cent (Latin-1 U+00A2), CJK water (BMP U+6C34),
-// G-Clef (non-BMP U+1D11E), PUA (BMP U+F8FF), PUA (non-BMP U+10FFFD)
-// byte-swapped BOM (non-character U+FFFE)
-const sample = 'z\xA2\u6C34\uD834\uDD1E\uF8FF\uDBFF\uDFFD\uFFFE';
-
-{
-  const encoding = 'utf-8';
-  const string = sample;
-  const bytes = [
-    0x7A, 0xC2, 0xA2, 0xE6, 0xB0, 0xB4,
-    0xF0, 0x9D, 0x84, 0x9E, 0xEF, 0xA3,
-    0xBF, 0xF4, 0x8F, 0xBF, 0xBD, 0xEF,
-    0xBF, 0xBE
-  ];
-  const encoded = new TextEncoder().encode(string);
-  assert.deepStrictEqual([].slice.call(encoded), bytes);
-  assert.strictEqual(
-    new TextDecoder(encoding).decode(new Uint8Array(bytes)),
-    string);
-  assert.strictEqual(
-    new TextDecoder(encoding).decode(new Uint8Array(bytes).buffer),
-    string);
-}
-
-testDecodeSample(
-  'utf-16le',
-  sample,
-  [
-    0x7A, 0x00, 0xA2, 0x00, 0x34, 0x6C,
-    0x34, 0xD8, 0x1E, 0xDD, 0xFF, 0xF8,
-    0xFF, 0xDB, 0xFD, 0xDF, 0xFE, 0xFF
-  ]
-);
-
-if (common.hasIntl) {
-  testDecodeSample(
-    'utf-16be',
-    sample,
-    [
-      0x00, 0x7A, 0x00, 0xA2, 0x6C, 0x34,
-      0xD8, 0x34, 0xDD, 0x1E, 0xF8, 0xFF,
-      0xDB, 0xFF, 0xDF, 0xFD, 0xFF, 0xFE
-    ]
-  );
-}
-
-testDecodeSample(
-  'utf-16',
-  sample,
-  [
-    0x7A, 0x00, 0xA2, 0x00, 0x34, 0x6C,
-    0x34, 0xD8, 0x1E, 0xDD, 0xFF, 0xF8,
-    0xFF, 0xDB, 0xFD, 0xDF, 0xFE, 0xFF
-  ]
-);
-
 {
   common.expectsError(
     () => new TextDecoder('utf-8', 1),
@@ -242,39 +179,3 @@ testDecodeSample(
     }
   );
 }
-
-// From: https://github.com/w3c/web-platform-tests/blob/master/encoding/api-invalid-label.html
-[
-  'utf-8',
-  'unicode-1-1-utf-8',
-  'utf8',
-  'utf-16be',
-  'utf-16le',
-  'utf-16'
-].forEach((i) => {
-  ['\u0000', '\u000b', '\u00a0', '\u2028', '\u2029'].forEach((ws) => {
-    common.expectsError(
-      () => new TextDecoder(`${ws}${i}`),
-      {
-        code: 'ERR_ENCODING_NOT_SUPPORTED',
-        type: RangeError
-      }
-    );
-
-    common.expectsError(
-      () => new TextDecoder(`${i}${ws}`),
-      {
-        code: 'ERR_ENCODING_NOT_SUPPORTED',
-        type: RangeError
-      }
-    );
-
-    common.expectsError(
-      () => new TextDecoder(`${ws}${i}${ws}`),
-      {
-        code: 'ERR_ENCODING_NOT_SUPPORTED',
-        type: RangeError
-      }
-    );
-  });
-});