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_bytestring.py

@@ -0,0 +1,125 @@
+# -*- coding: UTF-8 -*-
+
+import WebIDL
+
+
+def WebIDLTest(parser, harness):
+    parser.parse(
+        """
+        interface TestByteString {
+          attribute ByteString bs;
+          attribute DOMString ds;
+          };
+    """
+    )
+
+    results = parser.finish()
+
+    harness.ok(True, "TestByteString interface parsed without error.")
+
+    harness.check(len(results), 1, "Should be one production")
+    harness.ok(isinstance(results[0], WebIDL.IDLInterface), "Should be an IDLInterface")
+    iface = results[0]
+    harness.check(
+        iface.identifier.QName(), "::TestByteString", "Interface has the right QName"
+    )
+    harness.check(
+        iface.identifier.name, "TestByteString", "Interface has the right name"
+    )
+    harness.check(iface.parent, None, "Interface has no parent")
+
+    members = iface.members
+    harness.check(len(members), 2, "Should be two productions")
+
+    attr = members[0]
+    harness.ok(isinstance(attr, WebIDL.IDLAttribute), "Should be an IDLAttribute")
+    harness.check(
+        attr.identifier.QName(), "::TestByteString::bs", "Attr has correct QName"
+    )
+    harness.check(attr.identifier.name, "bs", "Attr has correct name")
+    harness.check(str(attr.type), "ByteString", "Attr type is the correct name")
+    harness.ok(attr.type.isByteString(), "Should be ByteString type")
+    harness.ok(attr.type.isString(), "Should be String collective type")
+    harness.ok(not attr.type.isDOMString(), "Should be not be DOMString type")
+
+    # now check we haven't broken DOMStrings in the process.
+    attr = members[1]
+    harness.ok(isinstance(attr, WebIDL.IDLAttribute), "Should be an IDLAttribute")
+    harness.check(
+        attr.identifier.QName(), "::TestByteString::ds", "Attr has correct QName"
+    )
+    harness.check(attr.identifier.name, "ds", "Attr has correct name")
+    harness.check(str(attr.type), "String", "Attr type is the correct name")
+    harness.ok(attr.type.isDOMString(), "Should be DOMString type")
+    harness.ok(attr.type.isString(), "Should be String collective type")
+    harness.ok(not attr.type.isByteString(), "Should be not be ByteString type")
+
+    # Cannot represent constant ByteString in IDL.
+    threw = False
+    try:
+        parser.parse(
+            """
+            interface ConstByteString {
+              const ByteString foo = "hello"
+              };
+        """
+        )
+    except WebIDL.WebIDLError:
+        threw = True
+    harness.ok(
+        threw, "Should have thrown a WebIDL error for ByteString default in interface"
+    )
+
+    # Can have optional ByteStrings with default values
+    try:
+        parser.parse(
+            """
+            interface OptionalByteString {
+              undefined passByteString(optional ByteString arg = "hello");
+              };
+        """
+        )
+        results2 = parser.finish()
+    except WebIDL.WebIDLError as e:
+        harness.ok(
+            False,
+            "Should not have thrown a WebIDL error for ByteString "
+            "default in dictionary. " + str(e),
+        )
+
+    # Can have a default ByteString value in a dictionary
+    try:
+        parser.parse(
+            """
+        dictionary OptionalByteStringDict {
+          ByteString item = "some string";
+        };
+        """
+        )
+        results3 = parser.finish()
+    except WebIDL.WebIDLError as e:
+        harness.ok(
+            False,
+            "Should not have thrown a WebIDL error for ByteString "
+            "default in dictionary. " + str(e),
+        )
+
+    # Don't allow control characters in ByteString literals
+    threw = False
+    try:
+        parser.parse(
+            """
+        dictionary OptionalByteStringDict2 {
+          ByteString item = "\x03";
+        };
+        """
+        )
+        results4 = parser.finish()
+    except WebIDL.WebIDLError as e:
+        threw = True
+
+    harness.ok(
+        threw,
+        "Should have thrown a WebIDL error for invalid ByteString "
+        "default in dictionary",
+    )