1 files changed, 50 insertions, 0 deletions
diff --git a/testing/web-platform/tests/encoding/textdecoder-arguments.any.js b/testing/web-platform/tests/encoding/textdecoder-arguments.any.js
new file mode 100644
index 0000000000..2d137b7aa3
--- /dev/null
+++ b/testing/web-platform/tests/encoding/textdecoder-arguments.any.js
@@ -0,0 +1,50 @@
+// META: global=window,dedicatedworker,shadowrealm
+// META: title=Encoding API: TextDecoder decode() optional arguments
+
+test(t => {
+  const decoder = new TextDecoder();
+
+  // Just passing nothing.
+  assert_equals(
+    decoder.decode(undefined), '',
+    'Undefined as first arg should decode to empty string');
+
+  // Flushing an incomplete sequence.
+  decoder.decode(new Uint8Array([0xc9]), {stream: true});
+  assert_equals(
+    decoder.decode(undefined), '\uFFFD',
+    'Undefined as first arg should flush the stream');
+
+}, 'TextDecoder decode() with explicit undefined');
+
+test(t => {
+  const decoder = new TextDecoder();
+
+  // Just passing nothing.
+  assert_equals(
+    decoder.decode(undefined, undefined), '',
+    'Undefined as first arg should decode to empty string');
+
+  // Flushing an incomplete sequence.
+  decoder.decode(new Uint8Array([0xc9]), {stream: true});
+  assert_equals(
+    decoder.decode(undefined, undefined), '\uFFFD',
+    'Undefined as first arg should flush the stream');
+
+}, 'TextDecoder decode() with undefined and undefined');
+
+test(t => {
+  const decoder = new TextDecoder();
+
+  // Just passing nothing.
+  assert_equals(
+    decoder.decode(undefined, {}), '',
+    'Undefined as first arg should decode to empty string');
+
+  // Flushing an incomplete sequence.
+  decoder.decode(new Uint8Array([0xc9]), {stream: true});
+  assert_equals(
+    decoder.decode(undefined, {}), '\uFFFD',
+    'Undefined as first arg should flush the stream');
+
+}, 'TextDecoder decode() with undefined and options');