1 files changed, 74 insertions, 0 deletions
diff --git a/dom/bindings/parser/tests/test_variadic_constraints.py b/dom/bindings/parser/tests/test_variadic_constraints.py
new file mode 100644
index 0000000000..8ffbfe0374
--- /dev/null
+++ b/dom/bindings/parser/tests/test_variadic_constraints.py
@@ -0,0 +1,74 @@
+def WebIDLTest(parser, harness):
+    threw = False
+    try:
+        parser.parse(
+            """
+            interface VariadicConstraints1 {
+              undefined foo(byte... arg1, byte arg2);
+            };
+        """
+        )
+        parser.finish()
+
+    except Exception:
+        threw = True
+
+    harness.ok(
+        threw,
+        "Should have thrown on variadic argument followed by required " "argument.",
+    )
+
+    parser = parser.reset()
+    threw = False
+    try:
+        parser.parse(
+            """
+            interface VariadicConstraints2 {
+              undefined foo(byte... arg1, optional byte arg2);
+            };
+        """
+        )
+        parser.finish()
+    except Exception:
+        threw = True
+
+    harness.ok(
+        threw,
+        "Should have thrown on variadic argument followed by optional " "argument.",
+    )
+
+    parser = parser.reset()
+    threw = False
+    try:
+        parser.parse(
+            """
+            interface VariadicConstraints3 {
+              undefined foo(optional byte... arg1);
+            };
+        """
+        )
+        parser.finish()
+
+    except Exception:
+        threw = True
+
+    harness.ok(
+        threw,
+        "Should have thrown on variadic argument explicitly flagged as " "optional.",
+    )
+
+    parser = parser.reset()
+    threw = False
+    try:
+        parser.parse(
+            """
+            interface VariadicConstraints4 {
+              undefined foo(byte... arg1 = 0);
+            };
+        """
+        )
+        parser.finish()
+    except Exception:
+        threw = True
+
+    harness.ok(threw, "Should have thrown on variadic argument with default value.")