1 files changed, 46 insertions, 0 deletions
diff --git a/testing/web-platform/tests/encoding/textdecoder-utf16-surrogates.any.js b/testing/web-platform/tests/encoding/textdecoder-utf16-surrogates.any.js
new file mode 100644
index 0000000000..7e8322cd19
--- /dev/null
+++ b/testing/web-platform/tests/encoding/textdecoder-utf16-surrogates.any.js
@@ -0,0 +1,46 @@
+// META: global=window,dedicatedworker,shadowrealm
+// META: title=Encoding API: UTF-16 surrogate handling
+
+var bad = [
+    {
+        encoding: 'utf-16le',
+        input: [0x00, 0xd8],
+        expected: '\uFFFD',
+        name: 'lone surrogate lead'
+    },
+    {
+        encoding: 'utf-16le',
+        input: [0x00, 0xdc],
+        expected: '\uFFFD',
+        name: 'lone surrogate trail'
+    },
+    {
+        encoding: 'utf-16le',
+        input: [0x00, 0xd8, 0x00, 0x00],
+        expected: '\uFFFD\u0000',
+        name: 'unmatched surrogate lead'
+    },
+    {
+        encoding: 'utf-16le',
+        input: [0x00, 0xdc, 0x00, 0x00],
+        expected: '\uFFFD\u0000',
+        name: 'unmatched surrogate trail'
+    },
+    {
+        encoding: 'utf-16le',
+        input: [0x00, 0xdc, 0x00, 0xd8],
+        expected: '\uFFFD\uFFFD',
+        name: 'swapped surrogate pair'
+    }
+];
+
+bad.forEach(function(t) {
+    test(function() {
+        assert_equals(new TextDecoder(t.encoding).decode(new Uint8Array(t.input)), t.expected);
+    }, t.encoding + ' - ' + t.name);
+    test(function() {
+        assert_throws_js(TypeError, function() {
+            new TextDecoder(t.encoding, {fatal: true}).decode(new Uint8Array(t.input))
+        });
+    }, t.encoding + ' - ' + t.name + ' (fatal flag set)');
+});