Dialyzer output

[johnkelly]

mix.lock

"gettext": {:hex, :gettext, "0.11.0"},

Relevant mix.exs dialyzer configuration in project function

      dialyzer: [
        plt_add_deps: true,
        plt_file: ".local.plt"
      ]

On a brand new elixir 1.2.5 phoenix project, I get the following output from the dialyzer.

mix dialyzer

gettext.ex:1: The inferred type for the 1st argument of 'MACRO-dgettext'/3 ({_,_}) is not a supertype of #{}, which is expected type for this argument in the callback of the 'Elixir.Gettext.Backend' behaviour
gettext.ex:1: The inferred type for the 1st argument of 'MACRO-dgettext'/4 ({_,_}) is not a supertype of #{}, which is expected type for this argument in the callback of the 'Elixir.Gettext.Backend' behaviour
gettext.ex:1: The inferred type for the 1st argument of 'MACRO-dngettext'/5 ({_,_}) is not a supertype of #{}, which is expected type for this argument in the callback of the 'Elixir.Gettext.Backend' behaviour
gettext.ex:1: The inferred type for the 1st argument of 'MACRO-dngettext'/6 ({_,_}) is not a supertype of #{}, which is expected type for this argument in the callback of the 'Elixir.Gettext.Backend' behaviour

[whatyouhide]

@josevalim any idea of what's going on here?

[josevalim]

Not sure. :(

[johnkelly]

When I search phoenix repo for dgettext or dngettext this turns up:

https://github.com/phoenixframework/phoenix/blob/bd4b9984397497a48b99c7b47d8b057c380af71b/installer/templates/new/web/views/error_helpers.ex#L35-L37

Is it because the first argument is an atom?

[josevalim]

@johnkelly the typespecs for those seem correct though: https://github.com/elixir-lang/gettext/blob/master/lib/gettext.ex#L501

I am thinking then it may rather be an issue with the macros defined in the Gettext backend?

[whatyouhide]

@josevalim is right, dialyzer is complaining about the macros defined by Gettext when you call use Gettext in your gettext module. As you can see, it mentions 'MACRO-dgettext'/3 and others but Gettext.*gettext (which you linked to above) are functions.

I really have no idea what's going on here 😕

[whatyouhide]

@ericmj and @fishcakez, I'm gonna go ahead and ping you as well here cause I really don't know where to start. Any ideas?

[ericmj]

Sorry, I don't use dialyzer.

[jeremyjh]

I put this in my gettext.ex module to silence these warnings.

   @dialyzer [{:nowarn_function, 'MACRO-dgettext': 3},
             {:nowarn_function, 'MACRO-dgettext': 4},
             {:nowarn_function, 'MACRO-dngettext': 5},
             {:nowarn_function, 'MACRO-dngettext': 6},
            ]

[whatyouhide]

@josevalim do you think it would be reasonable to put that in Gettext backends when we use Gettext?

[josevalim]

@whatyouhide I think we should rather fix this. @jeremyjh can you provide a simple app that reproduces those warnings so it makes it easier for us to fix this? Thank you!

[fishcakez]

This is fixed on Elixir master and the v1.3 branch, so will be included in v1.4.0 and v1.3.2 whenever they happen.