1 files changed, 52 insertions, 0 deletions
diff --git a/testing/web-platform/tests/encoding/textdecoder-ignorebom.any.js b/testing/web-platform/tests/encoding/textdecoder-ignorebom.any.js
new file mode 100644
index 0000000000..e825698ba4
--- /dev/null
+++ b/testing/web-platform/tests/encoding/textdecoder-ignorebom.any.js
@@ -0,0 +1,52 @@
+// META: global=window,dedicatedworker,shadowrealm
+// META: title=Encoding API: TextDecoder ignoreBOM option
+
+var cases = [
+    {encoding: 'utf-8', bytes: [0xEF, 0xBB, 0xBF, 0x61, 0x62, 0x63]},
+    {encoding: 'utf-16le', bytes: [0xFF, 0xFE, 0x61, 0x00, 0x62, 0x00, 0x63, 0x00]},
+    {encoding: 'utf-16be', bytes: [0xFE, 0xFF, 0x00, 0x61, 0x00, 0x62, 0x00, 0x63]}
+];
+
+cases.forEach(function(testCase) {
+    test(function() {
+        var BOM = '\uFEFF';
+        var decoder = new TextDecoder(testCase.encoding, {ignoreBOM: true});
+        var bytes = new Uint8Array(testCase.bytes);
+        assert_equals(
+            decoder.decode(bytes),
+            BOM + 'abc',
+            testCase.encoding + ': BOM should be present in decoded string if ignored');
+        assert_equals(
+            decoder.decode(bytes),
+            BOM + 'abc',
+            testCase.encoding + ': BOM should be present in decoded string if ignored by a reused decoder');
+
+        decoder = new TextDecoder(testCase.encoding, {ignoreBOM: false});
+        assert_equals(
+            decoder.decode(bytes),
+            'abc',
+            testCase.encoding + ': BOM should be absent from decoded string if not ignored');
+        assert_equals(
+            decoder.decode(bytes),
+            'abc',
+            testCase.encoding + ': BOM should be absent from decoded string if not ignored by a reused decoder');
+
+        decoder = new TextDecoder(testCase.encoding);
+        assert_equals(
+            decoder.decode(bytes),
+            'abc',
+            testCase.encoding + ': BOM should be absent from decoded string by default');
+        assert_equals(
+            decoder.decode(bytes),
+            'abc',
+            testCase.encoding + ': BOM should be absent from decoded string by default with a reused decoder');
+    }, 'BOM is ignored if ignoreBOM option is specified: ' + testCase.encoding);
+});
+
+test(function() {
+    assert_true('ignoreBOM' in new TextDecoder(), 'The ignoreBOM attribute should exist on TextDecoder.');
+    assert_equals(typeof  new TextDecoder().ignoreBOM, 'boolean', 'The type of the ignoreBOM attribute should be boolean.');
+    assert_false(new TextDecoder().ignoreBOM, 'The ignoreBOM attribute should default to false.');
+    assert_true(new TextDecoder('utf-8', {ignoreBOM: true}).ignoreBOM, 'The ignoreBOM attribute can be set using an option.');
+
+}, 'The ignoreBOM attribute of TextDecoder');