Google OAuth 2.0 failing with Error 400: invalid_request for some client_id, but works well for others in the same project

Please see https://stackoverflow.com/a/71491500/1213346 for a “proper” solution. This answer is just an ugly workaround that the community seems to like.

…

Here is a cringy workaround for this situation:

Replace urn:ietf:wg:oauth:2.0:oob with http://localhost:1/ in the code posted in the question. This makes the flow go through, my browser gets redirected and fails and I get an error messages like:

This site can’t be reached

The webpage at http://localhost:1/oauth2callback?
code=4/a3MU9MlhWxit8P7N8QsGtT0ye8GJygOeCa3MU9MlhWxit8P7N8QsGtT0y
e8GJygOeC&scope=email%20profile%20https... might be temporarily
down or it may have moved permanently to a new web address.

ERR_UNSAFE_PORT

Now copy the code code value from the failing URL, paste it into the app, and voila… same as before 🙂

P.S. Here is the updated “working” version:

def user_credentials_for(scope, user_id = 'default')
    token_store = Google::Auth::Stores::FileTokenStore.new(:file => token_store_path)
    authorizer = Google::Auth::UserAuthorizer.new(client_id, scope, token_store, "http://localhost:1/")
    credentials = authorizer.get_credentials(user_id)
    if credentials.nil?
        url = authorizer.get_authorization_url
        $stderr.puts ""
        $stderr.puts "-----------------------------------------------"
        $stderr.puts "Requesting authorization for '#{user_id}'"
        $stderr.puts "Open the following URL in your browser and authorize the application."
        $stderr.puts url
        $stderr.puts
        $stderr.puts "At the end the browser will fail to connect to http://localhost:1/?code=SOMECODE&scope=..."
        $stderr.puts "Copy the value of SOMECODE from the address and paste it below"

        code = $stdin.readline.chomp
        $stderr.puts "-----------------------------------------------"
        credentials = authorizer.get_and_store_credentials_from_code(
            user_id: user_id, code: code)
    end
    credentials
end                                                                                                                                      ```