1 files changed, 53 insertions, 0 deletions
diff --git a/dom/bindings/parser/tests/test_union_nullable.py b/dom/bindings/parser/tests/test_union_nullable.py
new file mode 100644
index 000000000..08430a94a
--- /dev/null
+++ b/dom/bindings/parser/tests/test_union_nullable.py
@@ -0,0 +1,53 @@
+def WebIDLTest(parser, harness):
+    threw = False
+    try:
+        parser.parse("""
+            interface OneNullableInUnion {
+              void foo((object? or DOMString?) arg);
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw,
+               "Two nullable member types of a union should have thrown.")
+
+    parser.reset()
+    threw = False
+
+    try:
+        parser.parse("""
+            interface NullableInNullableUnion {
+              void foo((object? or DOMString)? arg);
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw,
+               "A nullable union type with a nullable member type should have "
+               "thrown.")
+
+    parser.reset()
+    threw = False
+
+    try:
+        parser.parse("""
+            interface NullableInUnionNullableUnionHelper {
+            };
+            interface NullableInUnionNullableUnion {
+              void foo(((object? or DOMString) or NullableInUnionNullableUnionHelper)? arg);
+            };
+        """)
+
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw,
+               "A nullable union type with a nullable member type should have "
+               "thrown.")