Currently we do not have very clear errors regarding protocol.js and types in the protocol.js specs. At the moment it is a bit like working blind. Some cases that have been found: request: Arg(0, "json") is invalid request: { text: (0, "array:string") will take a simple string and turn it into an array there are no type checks for primitives tests fail silently. so far tests that fail silently include browser_addons_debug_webextension_popup and browser_addons_debug_console_context_menu and others, cases will be added as they are found