Module references in typespecs are not included when renaming modules

[jesperes]

Module references in typespecs are not included when renaming modules. This causes problems with OTP 22, as specs referencing functions in other modules are no longer permitted. See e.g. OTP-15563 in http://erlang.org/download/otp_src_22.0.readme:

OTP-15563    Application(s): compiler, stdlib
               Related Id(s): ERL-845, OTP-15562

               Do not allow function specifications for functions
               residing in other modules.

Reproduction Steps

1. Given the following module:

   -module(foo).
   -export([bar/0]).
   -spec ?MODULE:bar() -> ok.
   bar() -> ok.

2. Compile foo.erl with erlc +debug_info foo.erl

3. Start an Erlang shell and call mock:new(foo, [passthrough])

Expected behavior

mock:new/2 should return ok.

Observed behavior

mock:new/2 throws an exception:

** exception error: {compile_forms,{error,[{"foo.erl",
                                            [{4,erl_lint,{bad_module,{foo,main,0}}}]}],
                                          []}}
     in function  meck_proc:start/2
        called as meck_proc:start(foo,[passthrough])

Versions

• Meck 0.8.12
• Erlang/OTP 22.1.8

[jesperes]

The problem is in meck_code:rename_module/2 which only modifieds the module attribute, and ignores any typespecs found in the file:

-spec rename_module(erlang_form(), module()) -> erlang_form().
rename_module([{attribute, Line, module, OldAttribute}|T], NewName) ->
    case OldAttribute of
        {_OldName, Variables} ->
            [{attribute, Line, module, {NewName, Variables}}|T];
        _OldName ->
            [{attribute, Line, module, NewName}|T]
    end;
rename_module([H|T], NewName) ->
    [H|rename_module(T, NewName)].

[eproxus]

Thanks for the pointer! I'll take a look at as soon as I can.