Fix incorrect coverage count when prod modules include EUnit header.

Modules that include the EUnit header get an implicit test/0 fun, which cover considers a runnable line, but eunit:(TestRepresentation) never calls. Result: prod modules with tests can never reach 100% coverage. Ironic. In this case, fix it by decrementing the NotCovered counter returned by cover:analyze/3.
pirms 15 gadiem · 4825353a23
--- a/src/rebar_eunit.erl
+++ b/src/rebar_eunit.erl
@ -238,13 +238,43 @@ cover_init(Config, BeamFiles) ->
 cover_analyze_mod(Module) ->
    case cover:analyze(Module, coverage, module) of
        {ok, {Module, {Covered, NotCovered}}} ->
            {Module, Covered, NotCovered};
            %% Modules that include the eunit header get an implicit
            %% test/0 fun, which cover considers a runnable line, but
            %% eunit:test(TestRepresentation) never calls.  Decrement
            %% NotCovered in this case.
            align_notcovered_count(Module, Covered, NotCovered,
                                   is_eunitized(Module));
        {error, Reason} ->
            ?ERROR("Cover analyze failed for ~p: ~p ~p\n",
                   [Module, Reason, code:which(Module)]),
            {0,0}
    end.
 is_eunitized(Mod) ->
    has_eunit_test_fun(Mod) andalso
        has_eunit_header(Mod).
 has_eunit_test_fun(Mod) ->
    length([F || {exports, Funs} <- Mod:module_info(),
                    {F, 0} <- Funs,
                    F == test]) =/= 0.
 has_eunit_header(Mod) ->
    OrigEnv = set_proc_env(),
    try has_header(Mod, "include/eunit.hrl")
    after restore_proc_env(OrigEnv)
    end.
 has_header(Mod, Header) ->
    {ok, {_, [{abstract_code, {_, AC}}]}} = beam_lib:chunks(Mod, [abstract_code]),
    length([F || {attribute, 1, file, {F, 1}} <- AC,
                 string:str(F, Header) =/= 0]) =/= 0.
 align_notcovered_count(Module, Covered, NotCovered, false) ->
    {Module, Covered, NotCovered};
 align_notcovered_count(Module, Covered, NotCovered, true) ->
    {Module, Covered, NotCovered - 1}.
 cover_write_index(Coverage, SrcModules) ->
    {ok, F} = file:open(filename:join([?EUNIT_DIR, "index.html"]), [write]),
    ok = file:write(F, "<html><head><title>Coverage Summary</title></head>\n"),
--- a/test/rebar_eunit_tests.erl
+++ b/test/rebar_eunit_tests.erl
@ -88,14 +88,25 @@ cover_with_suite_test_() ->
      {"Only production modules get coverage reports",
       assert_files_not_in("the temporary eunit directory",
                           [".eunit/myapp_mymod_tests.COVER.html",
                            ".eunit/mysuite"])}]}.             
                            ".eunit/mysuite.COVER.html"])}]}.
 expected_cover_generated_files() ->
    [".eunit/index.html",
     ".eunit/myapp_app.COVER.html",
     ".eunit/myapp_mymod.COVER.html",
     ".eunit/myapp_sup.COVER.html"].
 cover_coverage_test_() ->
    {"Coverage is accurately calculated",
     setup, fun() -> setup_cover_project(), rebar("-v eunit") end,
     fun teardown/1,
     [{"Modules that include the EUnit header can still have 100% coverage",
       %% cover notices the implicit EUnit test/0 func that never gets
       %% called during eunit:test(TestRepresentation), so NotCounted
       %% needs to be decremented in this case.
       assert_full_coverage("myapp_mymod")}]}.
 %% ====================================================================
 %% Environment and Setup Tests
 %% ====================================================================
@ -227,3 +238,12 @@ assert_files_not_in(Name, [File|T]) ->
     assert_files_not_in(Name, T)];   
 assert_files_not_in(_, []) -> [].
 assert_full_coverage(Mod) ->
    fun() ->
            {ok, F} = file:read_file(".eunit/index.html"),
            Result = [X || X <- string:tokens(binary_to_list(F), "\n"),
                           string:str(X, Mod) =/= 0,
                           string:str(X, "100%") =/= 0],
            file:close(F),
            ?assert(length(Result) == 1)
    end.