AK: JsonParser improvements

- Parsing invalid JSON no longer asserts
    Instead of asserting when coming across malformed JSON,
    JsonParser::parse now returns an Optional<JsonValue>.
- Disallow trailing commas in JSON objects and arrays
- No longer parse 'undefined', as that is a purely JS thing
- No longer allow non-whitespace after anything consumed by the initial
  parse() call. Examples of things that were valid and no longer are:
    - undefineddfz
    - {"foo": 1}abcd
    - [1,2,3]4
- JsonObject.for_each_member now iterates in original insertion order

1 files changed, 3 insertions, 1 deletions

diff --git a/DevTools/FormCompiler/main.cpp b/DevTools/FormCompiler/main.cpp
index 0ccafa31ce..7113f510fc 100644
--- a/DevTools/FormCompiler/main.cpp
+++ b/DevTools/FormCompiler/main.cpp
@@ -46,7 +46,9 @@ int main(int argc, char** argv)
     }
 
     auto file_contents = file->read_all();
-    auto json = JsonValue::from_string(file_contents);
+    auto json_result = JsonValue::from_string(file_contents);
+    ASSERT(json_result.has_value());
+    auto json = json_result.value();
 
     if (!json.is_object()) {
         fprintf(stderr, "Malformed input\n");