Create a top-level "third_party" directory

This directory now contains third_party software that is vendored into
the Servo source tree. The idea is that it would eventually hold
webrender and other crates from mozilla-central as well with a standard
patch management approach for each.

third_party/WebIDL/tests/test_enum.py

@@ -0,0 +1,107 @@
+import WebIDL
+
+
+def WebIDLTest(parser, harness):
+    parser.parse(
+        """
+        enum TestEnum {
+          "",
+          "foo",
+          "bar"
+        };
+
+        interface TestEnumInterface {
+          TestEnum doFoo(boolean arg);
+          readonly attribute TestEnum foo;
+        };
+    """
+    )
+
+    results = parser.finish()
+
+    harness.ok(True, "TestEnumInterfaces interface parsed without error.")
+    harness.check(len(results), 2, "Should be one production")
+    harness.ok(isinstance(results[0], WebIDL.IDLEnum), "Should be an IDLEnum")
+    harness.ok(isinstance(results[1], WebIDL.IDLInterface), "Should be an IDLInterface")
+
+    enum = results[0]
+    harness.check(enum.identifier.QName(), "::TestEnum", "Enum has the right QName")
+    harness.check(enum.identifier.name, "TestEnum", "Enum has the right name")
+    harness.check(enum.values(), ["", "foo", "bar"], "Enum has the right values")
+
+    iface = results[1]
+
+    harness.check(
+        iface.identifier.QName(), "::TestEnumInterface", "Interface has the right QName"
+    )
+    harness.check(
+        iface.identifier.name, "TestEnumInterface", "Interface has the right name"
+    )
+    harness.check(iface.parent, None, "Interface has no parent")
+
+    members = iface.members
+    harness.check(len(members), 2, "Should be one production")
+    harness.ok(isinstance(members[0], WebIDL.IDLMethod), "Should be an IDLMethod")
+    method = members[0]
+    harness.check(
+        method.identifier.QName(),
+        "::TestEnumInterface::doFoo",
+        "Method has correct QName",
+    )
+    harness.check(method.identifier.name, "doFoo", "Method has correct name")
+
+    signatures = method.signatures()
+    harness.check(len(signatures), 1, "Expect one signature")
+
+    (returnType, arguments) = signatures[0]
+    harness.check(
+        str(returnType), "TestEnum (Wrapper)", "Method type is the correct name"
+    )
+    harness.check(len(arguments), 1, "Method has the right number of arguments")
+    arg = arguments[0]
+    harness.ok(isinstance(arg, WebIDL.IDLArgument), "Should be an IDLArgument")
+    harness.check(str(arg.type), "Boolean", "Argument has the right type")
+
+    attr = members[1]
+    harness.check(
+        attr.identifier.QName(), "::TestEnumInterface::foo", "Attr has correct QName"
+    )
+    harness.check(attr.identifier.name, "foo", "Attr has correct name")
+
+    harness.check(str(attr.type), "TestEnum (Wrapper)", "Attr type is the correct name")
+
+    # Now reset our parser
+    parser = parser.reset()
+    threw = False
+    try:
+        parser.parse(
+            """
+          enum Enum {
+            "a",
+            "b",
+            "c"
+          };
+          interface TestInterface {
+            undefined foo(optional Enum e = "d");
+          };
+        """
+        )
+        results = parser.finish()
+    except:
+        threw = True
+
+    harness.ok(threw, "Should not allow a bogus default value for an enum")
+
+    # Now reset our parser
+    parser = parser.reset()
+    parser.parse(
+        """
+      enum Enum {
+        "a",
+        "b",
+        "c",
+      };
+    """
+    )
+    results = parser.finish()
+    harness.check(len(results), 1, "Should allow trailing comma in enum")