Format and type specs

[robinmonjo]

The goal of this PR is to use the Elixir 1.6 code formatter and write type specs on the entire codebase

So far I set up the code formatter. I had to:

• install Elixir 1.6 locally (obviously)
• install Elixir from source in Travis so I can run the formatter check
• get credo from the master branch to avoid this issue on Elixir 1.6: https://github.com/rrrene/credo/issues/463

TODOs:

• [x] ensure I follow Jose advices from https://github.com/elixir-lang/elixir/issues/6643 on how to handle formatting
• [x] write type specs !!
• [x] do this https://github.com/robinmonjo/coincoin/issues/18 type specs will be better
• [ ] run dialyzer in the CI ? (this will make things slow or maybe Travis can cache PLT ?) possible http://blog.danielberkompas.com/elixir/2015/04/03/run-dialyzer-on-elixir-on-travis.html but won't do it ...

Once Elixir 1.6 is released I will have to "simplify" the travis.yml

Fix: https://github.com/robinmonjo/coincoin/issues/14 Fix: https://github.com/robinmonjo/coincoin/issues/18

[robinmonjo]

Ok I think I'm done with this PR. @yordis if you want to have a look, be my guest 😊

[yordis]

Did you ran elixir format?

[robinmonjo]

Yes I did ran mix format, formatting is also checked by CI but I didn't include .formatter.exs in the list of file to format 😊. Fixed in last commit

[yordis]

Add .editorconfig, it will help with situations of trimming the spaces and adding the jump of line at the end of the file

# .editorconfig
root = true

[*]
indent_style = space
indent_size = 2
end_of_line = lf
charset = utf-8
trim_trailing_whitespace = true
insert_final_newline = true

[*.md]
trim_trailing_whitespace = false

[yordis]

Well you need to install the plugin for your editor for sure 😄

[robinmonjo]

Don't you think this would be redundant with mix format ? I think mix format already ensure everything you list in the config file

[yordis]

@robinmonjo does mix format add the jump at the end of the file or trim trailing whitespace?

I think it doesn't because some of your files are missing the jump at the end of the line

Also is for all the files on the system

[robinmonjo]

Yes it does add the jumpline (only on files that matches the patterns defined in .formatter.exs. As for trailing whitespaces I'm not sure my editor does it for me. Will take a look at editor config (you are the first one who talk to me about this)

[yordis]

I like editorconfig because you help the people that contributes to the project and you mitigate the issue with IDE/Editors configuration, at least they could install the plugin (which some of the editors and IDE already have it by default) and it will help us out.

[robinmonjo]

Ok @yordis I added the .editorconfig file :+1:

[robinmonjo]

@yordis is it all good for you ? Should we merge this ?

[yordis]

@robinmonjo all good man! Amazing work 😎

[robinmonjo]

👍 thanks again for the review and advices ! I started to read the "Metaprogramming Elixir" book to see what can be done with the AST and how to use it to build a "blockchain language" for smart contracts. Lot's of work, big subject but might be interesting :)