Reliance on inets?

[Bastes]

Hi,

Using assent to authenticate through oauth2 on a micro-app that had no ecto backup nor need to record user information past authorization, I encountered an error after the built succeed:

web_1  | ** (exit) an exception was raised:
web_1  |     ** (UndefinedFunctionError) function :httpc.request/4 is undefined (module :httpc is not available)
web_1  |         :httpc.request(:post, {'https://api.intra.42.fr/oauth/token', [{'User-Agent', 'Assent-0.1.16'}], 'application/x-www-form-urlencoded', 'code=d44d4959376eb30953852cc66cb4ebce50c4018dfda2dc79ebd26414bcac3ab2&redirect_uri=http%3A%2F%2Flocalhost%3A4000%2Fsession%2Fcallback&grant_type=authorization_code&client_id=54d568770a5f2984fdacf76bcf38d469edbe71b55ccd050dd83a63fd94f0ac6b&client_secret=b237063058109ba31701030463a9a77616fecab6b866e53f1b50e1c03da9d3e5'}, [], [])
web_1  |         (assent) lib/assent/http_adapter/httpc.ex:25: Assent.HTTPAdapter.Httpc.request/5
web_1  |         (assent) lib/assent/strategy.ex:42: Assent.Strategy.request/5
web_1  |         (assent) lib/assent/strategies/oauth2.ex:250: Assent.Strategy.OAuth2.grant_access_token/3
web_1  |         (assent) lib/assent/strategies/oauth2.ex:129: Assent.Strategy.OAuth2.callback/3
# ... here be where the binding was used in my app

That happened during the callback of the oauth2 transaction, and completely baffled me. It looked like something like a missing dependency or something, yet I did not see anything like this in assent's docs, and when I googled it, it looked exactly like the inets lib was missing...

I finally figured out how to fix this, adding inets to the extra_applications:

# in app/mix.exs
  def application do
    [
      # ...
      extra_applications: [
        # ...
        :inets
      ]
    ]
  end

...aaaand... that worked.

Maybe it should be noted in the installation docs that inets is necessary to be started for it to work. I'm willing to make a PR explaining it, but I'd like for someone knowing assent from the inside out to explain why and in which cases it's necessary to have inets as a dependency first (so I don't mislead others either).

So, there. Thank you for that awesome lib by the way.

[danschultzer]

Good catch, thanks! I've updated the docs 😄

:httpc is optional so I've decided not to load :inets in case you are using another HTTP adapter that doesn't depend on it. No need to load and compile `:inets into the app in that case.

[Bastes]

Happy to help :) thanks for the fix.