Avoid crashing on empty JSON data

[MikeAski]

I encounter the following error on a regular basis:

/Users/mike/.rubies/ruby-2.3.1/lib/ruby/2.3.0/json/common.rb:156:in `initialize': A JSON text must at least contain two octets! (JSON::ParserError)
    from /Users/mike/.rubies/ruby-2.3.1/lib/ruby/2.3.0/json/common.rb:156:in `new'
    from /Users/mike/.rubies/ruby-2.3.1/lib/ruby/2.3.0/json/common.rb:156:in `parse'
    from /Users/mike/.gem/ruby/2.3.1/gems/action_cable_client-1.3.3/lib/action_cable_client.rb:166:in `handle_received_message'
    from /Users/mike/.gem/ruby/2.3.1/gems/action_cable_client-1.3.3/lib/action_cable_client.rb:74:in `block in received'
    from /Users/mike/.gem/ruby/2.3.1/gems/em-websocket-client-0.1.2/lib/em-websocket-client.rb:43:in `receive_data'
    from /Users/mike/.gem/ruby/2.3.1/gems/eventmachine-1.2.0.1/lib/eventmachine.rb:194:in `run_machine'
    from /Users/mike/.gem/ruby/2.3.1/gems/eventmachine-1.2.0.1/lib/eventmachine.rb:194:in `run'

This PR fixes the issue: exit processing on empty payload.

[NullVoxPopuli]

Hey! thanks for this!

Anyway you could add a test real quick?

[NullVoxPopuli]

@MikeAski what version of rails are you using?

[MikeAski]

I am using Rails 5.0.0.1

[NullVoxPopuli]

thanks for the test!

[NullVoxPopuli]

I'll get this released right away

[NullVoxPopuli]

@MikeAski

• https://github.com/NullVoxPopuli/action_cable_client/blob/master/CHANGELOG.md#134
• https://rubygems.org/gems/action_cable_client/versions/1.3.4

Gem Pushed. :-)

[NullVoxPopuli]

thanks for your work!

[MikeAski]

Thanks a lot for your reactivity! 👍