"TypeError: Cannot read property 'pseudoType' of undefined" with chrome-devtools
I think that the problems here could be of two different types: the path is incorrect, there is already a path that exists as the one you passed as a parameter or you are calling this function before that the module app is on its ready state.
To solve the first problem i would test the path that os.homedir() gives you back in a different part of the code to see what ends up to be at the time that you join it with the path indicatedin the function join; "/Library/Application/Support/Google/Chrome/Default/Extensions/fmkadmapgofadopljbjfkapdkoienihi/3.6.0_0".
To solve the second problem i would refactor the code to call the function in the appropriate lifecycle point to be sure that the app module is on the ready state.