I've been working through the File API mobile-spec failures on BlackBerry and have encountered some inconsistency in how error codes in the JS are handled. Some of the JS API (DirectoryEntry.removeRecursively, DirectoryReader.readEntries, Entry,getMetadata, Entry.getParent, window.requestFileSystem) expect the native side to return a FileError object in the error result, while the rest expect the native side to just return an integer error code (which is used on JS side to create FileError object).
Should the native code return a FileError object or just the integer error code? We need to choose one because it is too error prone/frustrating right now to try to get the native side to properly handle the error for each individual API.