Merge pull request #112 from tuncer/horvand-cover-for-qc

Add code coverage analysis functionality to `qc'

6 files changed, 307 insertions, 237 deletions

diff --git a/THANKS b/THANKS
index ee95cee..ef359ac 100644
--- a/THANKS
+++ b/THANKS
@@ -125,3 +125,4 @@ YeJun Su
 Yuki Ito
 alisdair sullivan
 Alexander Verbitsky
+Andras Horvath
diff --git a/dialyzer_reference b/dialyzer_reference
index 88909a6..c32104f 100644
--- a/dialyzer_reference
+++ b/dialyzer_reference
@@ -1,3 +1,3 @@
 
-rebar_eunit.erl:469: Call to missing or unexported function eunit_test:function_wrapper/2
-rebar_utils.erl:164: Call to missing or unexported function escript:foldl/3
+rebar_eunit.erl:471: Call to missing or unexported function eunit_test:function_wrapper/2
+rebar_utils.erl:184: Call to missing or unexported function escript:foldl/3
diff --git a/ebin/rebar.app b/ebin/rebar.app
index 29ad8cf..cc9f751 100644
--- a/ebin/rebar.app
+++ b/ebin/rebar.app
@@ -14,6 +14,7 @@
               rebar_cleaner,
               rebar_config,
               rebar_core,
+              rebar_cover_utils,
               rebar_ct,
               rebar_deps,
               rebar_edoc,
diff --git a/src/rebar_cover_utils.erl b/src/rebar_cover_utils.erl
new file mode 100644
index 0000000..3195fe2
--- /dev/null
+++ b/src/rebar_cover_utils.erl
@@ -0,0 +1,261 @@
+%% -*- erlang-indent-level: 4;indent-tabs-mode: nil -*-
+%% ex: ts=4 sw=4 et
+%% -------------------------------------------------------------------
+%%
+%% rebar: Erlang Build Tools
+%%
+%% Copyright (c) 2009, 2010 Dave Smith (dizzyd@dizzyd.com)
+%% Copyright (c) 2013 Andras Horvath (andras.horvath@erlang-solutions.com)
+%%
+%% Permission is hereby granted, free of charge, to any person obtaining a copy
+%% of this software and associated documentation files (the "Software"), to deal
+%% in the Software without restriction, including without limitation the rights
+%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+%% copies of the Software, and to permit persons to whom the Software is
+%% furnished to do so, subject to the following conditions:
+%%
+%% The above copyright notice and this permission notice shall be included in
+%% all copies or substantial portions of the Software.
+%%
+%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+%% THE SOFTWARE.
+%% -------------------------------------------------------------------
+-module(rebar_cover_utils).
+
+%% for internal use only
+-export([init/3,
+         perform_cover/4,
+         close/1,
+         exit/0]).
+
+-include("rebar.hrl").
+
+%% ====================================================================
+%% Internal functions
+%% ====================================================================
+
+perform_cover(Config, BeamFiles, SrcModules, TargetDir) ->
+    perform_cover(rebar_config:get(Config, cover_enabled, false),
+                  Config, BeamFiles, SrcModules, TargetDir).
+
+perform_cover(false, _Config, _BeamFiles, _SrcModules, _TargetDir) ->
+    ok;
+perform_cover(true, Config, BeamFiles, SrcModules, TargetDir) ->
+    analyze(Config, BeamFiles, SrcModules, TargetDir).
+
+close(not_enabled) ->
+    ok;
+close(F) ->
+    ok = file:close(F).
+
+exit() ->
+   cover:stop().
+
+init(false, _BeamFiles, _TargetDir) ->
+    {ok, not_enabled};
+init(true, BeamFiles, TargetDir) ->
+    %% Attempt to start the cover server, then set its group leader to
+    %% TargetDir/cover.log, so all cover log messages will go there instead of
+    %% to stdout. If the cover server is already started, we'll kill that
+    %% server and start a new one in order not to inherit a polluted
+    %% cover_server state.
+    {ok, CoverPid} = case whereis(cover_server) of
+                         undefined ->
+                             cover:start();
+                         _         ->
+                             cover:stop(),
+                             cover:start()
+                     end,
+
+    {ok, F} = OkOpen = file:open(
+                         filename:join([TargetDir, "cover.log"]),
+                         [write]),
+
+    group_leader(F, CoverPid),
+
+    ?INFO("Cover compiling ~s\n", [rebar_utils:get_cwd()]),
+
+    Compiled = [{Beam, cover:compile_beam(Beam)} || Beam <- BeamFiles],
+    case [Module || {_, {ok, Module}} <- Compiled] of
+        [] ->
+            %% No modules compiled successfully...fail
+            ?ERROR("Cover failed to compile any modules; aborting.~n", []),
+            ?FAIL;
+        _ ->
+            %% At least one module compiled successfully
+
+            %% It's not an error for cover compilation to fail partially,
+            %% but we do want to warn about them
+            PrintWarning =
+                fun(Beam, Desc) ->
+                        ?CONSOLE("Cover compilation warning for ~p: ~p",
+                                 [Beam, Desc])
+                end,
+            _ = [PrintWarning(Beam, Desc) || {Beam, {error, Desc}} <- Compiled],
+            OkOpen
+    end;
+init(Config, BeamFiles, TargetDir) ->
+    init(rebar_config:get(Config, cover_enabled, false), BeamFiles, TargetDir).
+
+analyze(_Config, [], _SrcModules, _TargetDir) ->
+    ok;
+analyze(Config, FilteredModules, SrcModules, TargetDir) ->
+    %% Generate coverage info for all the cover-compiled modules
+    Coverage = lists:flatten([analyze_mod(M)
+                              || M <- FilteredModules,
+                                 cover:is_compiled(M) =/= false]),
+
+    %% Write index of coverage info
+    write_index(lists:sort(Coverage), SrcModules, TargetDir),
+
+    %% Write coverage details for each file
+    lists:foreach(
+      fun({M, _, _}) ->
+              {ok, _} = cover:analyze_to_file(M,
+                                              cover_file(M, TargetDir),
+                                              [html])
+      end, Coverage),
+
+    Index = filename:join([rebar_utils:get_cwd(), TargetDir, "index.html"]),
+    ?CONSOLE("Cover analysis: ~s\n", [Index]),
+
+    %% Export coverage data, if configured
+    case rebar_config:get(Config, cover_export_enabled, false) of
+        true ->
+            export_coverdata(TargetDir);
+        false ->
+            ok
+    end,
+
+    %% Print coverage report, if configured
+    case rebar_config:get(Config, cover_print_enabled, false) of
+        true ->
+            print_coverage(lists:sort(Coverage));
+        false ->
+            ok
+    end.
+
+analyze_mod(Module) ->
+    case cover:analyze(Module, coverage, module) of
+        {ok, {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)]),
+            []
+    end.
+
+is_eunitized(Mod) ->
+    has_eunit_test_fun(Mod) andalso
+        has_header(Mod, "include/eunit.hrl").
+
+has_eunit_test_fun(Mod) ->
+    [F || {exports, Funs} <- Mod:module_info(),
+          {F, 0} <- Funs, F =:= test] =/= [].
+
+has_header(Mod, Header) ->
+    Mod1 = case code:which(Mod) of
+               cover_compiled ->
+                   {file, File} = cover:is_compiled(Mod),
+                   File;
+               non_existing -> Mod;
+               preloaded -> Mod;
+               L -> L
+           end,
+    {ok, {_, [{abstract_code, {_, AC}}]}} =
+        beam_lib:chunks(Mod1, [abstract_code]),
+    [F || {attribute, 1, file, {F, 1}} <- AC,
+          string:str(F, Header) =/= 0] =/= [].
+
+align_notcovered_count(Module, Covered, NotCovered, false) ->
+    {Module, Covered, NotCovered};
+align_notcovered_count(Module, Covered, NotCovered, true) ->
+    {Module, Covered, NotCovered - 1}.
+
+write_index(Coverage, SrcModules, TargetDir) ->
+    {ok, F} = file:open(filename:join([TargetDir, "index.html"]), [write]),
+    ok = file:write(F, "<!DOCTYPE HTML><html>\n"
+                    "<head><meta charset=\"utf-8\">"
+                    "<title>Coverage Summary</title></head>\n"
+                    "<body>\n"),
+    IsSrcCoverage = fun({Mod,_C,_N}) -> lists:member(Mod, SrcModules) end,
+    {SrcCoverage, TestCoverage} = lists:partition(IsSrcCoverage, Coverage),
+    write_index_section(F, "Source", SrcCoverage),
+    write_index_section(F, "Test", TestCoverage),
+    ok = file:write(F, "</body></html>"),
+    ok = file:close(F).
+
+write_index_section(_F, _SectionName, []) ->
+    ok;
+write_index_section(F, SectionName, Coverage) ->
+    %% Calculate total coverage
+    {Covered, NotCovered} = lists:foldl(fun({_Mod, C, N}, {CAcc, NAcc}) ->
+                                                {CAcc + C, NAcc + N}
+                                        end, {0, 0}, Coverage),
+    TotalCoverage = percentage(Covered, NotCovered),
+
+    %% Write the report
+    ok = file:write(F, ?FMT("<h1>~s Summary</h1>\n", [SectionName])),
+    ok = file:write(F, ?FMT("<h3>Total: ~s</h3>\n", [TotalCoverage])),
+    ok = file:write(F, "<table><tr><th>Module</th><th>Coverage %</th></tr>\n"),
+
+    FmtLink =
+        fun(Module, Cov, NotCov) ->
+                ?FMT("<tr><td><a href='~s.COVER.html'>~s</a></td><td>~s</td>\n",
+                     [Module, Module, percentage(Cov, NotCov)])
+        end,
+    lists:foreach(fun({Module, Cov, NotCov}) ->
+                          ok = file:write(F, FmtLink(Module, Cov, NotCov))
+                  end, Coverage),
+    ok = file:write(F, "</table>\n").
+
+print_coverage(Coverage) ->
+    {Covered, NotCovered} = lists:foldl(fun({_Mod, C, N}, {CAcc, NAcc}) ->
+                                                {CAcc + C, NAcc + N}
+                                        end, {0, 0}, Coverage),
+    TotalCoverage = percentage(Covered, NotCovered),
+
+    %% Determine the longest module name for right-padding
+    Width = lists:foldl(fun({Mod, _, _}, Acc) ->
+                                case length(atom_to_list(Mod)) of
+                                    N when N > Acc ->
+                                        N;
+                                    _ ->
+                                        Acc
+                                end
+                        end, 0, Coverage) * -1,
+
+    %% Print the output the console
+    ?CONSOLE("~nCode Coverage:~n", []),
+    lists:foreach(fun({Mod, C, N}) ->
+                          ?CONSOLE("~*s : ~3s~n",
+                                   [Width, Mod, percentage(C, N)])
+                  end, Coverage),
+    ?CONSOLE("~n~*s : ~s~n", [Width, "Total", TotalCoverage]).
+
+cover_file(Module, TargetDir) ->
+    filename:join([TargetDir, atom_to_list(Module) ++ ".COVER.html"]).
+
+export_coverdata(TargetDir) ->
+    ExportFile = filename:join(TargetDir, "cover.coverdata"),
+    case cover:export(ExportFile) of
+        ok ->
+            ?CONSOLE("Coverdata export: ~s~n", [ExportFile]);
+        {error, Reason} ->
+            ?ERROR("Coverdata export failed: ~p~n", [Reason])
+    end.
+
+percentage(0, 0) ->
+    "not executed";
+percentage(Cov, NotCov) ->
+    integer_to_list(trunc((Cov / (Cov + NotCov)) * 100)) ++ "%".
diff --git a/src/rebar_eunit.erl b/src/rebar_eunit.erl
index 8532af1..a5b7b00 100644
--- a/src/rebar_eunit.erl
+++ b/src/rebar_eunit.erl
@@ -157,18 +157,20 @@ run_eunit(Config, CodePath, SrcErls) ->
 
     %% Get matching tests and modules
     AllModules = [rebar_utils:beam_to_mod(?EUNIT_DIR, N) || N <- AllBeamFiles],
-    {Tests, CoverageModules} =
+    {Tests, FilteredModules} =
         get_tests_and_modules(Config, ModuleBeamFiles, AllModules),
 
     SrcModules = [rebar_utils:erl_to_mod(M) || M <- SrcErls],
 
-    {ok, CoverLog} = cover_init(Config, ModuleBeamFiles),
+    {ok, CoverLog} = rebar_cover_utils:init(Config, ModuleBeamFiles,
+                                            eunit_dir()),
 
     StatusBefore = status_before_eunit(),
     EunitResult = perform_eunit(Config, Tests),
 
-    perform_cover(Config, CoverageModules, SrcModules),
-    cover_close(CoverLog),
+    rebar_cover_utils:perform_cover(Config, FilteredModules, SrcModules,
+                                    eunit_dir()),
+    rebar_cover_utils:close(CoverLog),
 
     case proplists:get_value(reset_after_eunit, get_eunit_opts(Config),
                              true) of
@@ -180,7 +182,7 @@ run_eunit(Config, CodePath, SrcErls) ->
 
     %% Stop cover to clean the cover_server state. This is important if we want
     %% eunit+cover to not slow down when analyzing many Erlang modules.
-    ok = cover:stop(),
+    ok = rebar_cover_utils:exit(),
 
     case EunitResult of
         ok ->
@@ -219,9 +221,9 @@ get_tests_and_modules(Config, ModuleBeamFiles, AllModules) ->
     {Tests, QualifiedTests} = get_qualified_and_unqualified_tests(Config),
     Modules = get_test_modules(SelectedSuites, Tests,
                                QualifiedTests, ModuleBeamFiles),
-    CoverageModules = get_coverage_modules(AllModules, Modules, QualifiedTests),
+    FilteredModules = get_matching_modules(AllModules, Modules, QualifiedTests),
     MatchedTests = get_matching_tests(Modules, Tests, QualifiedTests),
-    {MatchedTests, CoverageModules}.
+    {MatchedTests, FilteredModules}.
 
 %%
 %% == get suites specified via 'suites' option ==
@@ -329,7 +331,7 @@ get_test_modules(SelectedSuites, Tests, QualifiedTests, ModuleBeamFiles) ->
                 N <- ModuleBeamFiles]
     end.
 
-get_coverage_modules(AllModules, Modules, QualifiedTests) ->
+get_matching_modules(AllModules, Modules, QualifiedTests) ->
     ModuleFilterMapper =
         fun({M, _}) ->
                 case lists:member(M, AllModules) of
@@ -499,226 +501,6 @@ get_eunit_opts(Config) ->
     BaseOpts ++ rebar_config:get_list(Config, eunit_opts, []).
 
 %%
-%% == code coverage ==
-%%
-
-perform_cover(Config, BeamFiles, SrcModules) ->
-    perform_cover(rebar_config:get(Config, cover_enabled, false),
-                  Config, BeamFiles, SrcModules).
-
-perform_cover(false, _Config, _BeamFiles, _SrcModules) ->
-    ok;
-perform_cover(true, Config, BeamFiles, SrcModules) ->
-    cover_analyze(Config, BeamFiles, SrcModules).
-
-cover_analyze(_Config, [], _SrcModules) ->
-    ok;
-cover_analyze(Config, FilteredModules, SrcModules) ->
-    %% Generate coverage info for all the cover-compiled modules
-    Coverage = lists:flatten([cover_analyze_mod(M)
-                              || M <- FilteredModules,
-                                 cover:is_compiled(M) =/= false]),
-
-    %% Write index of coverage info
-    cover_write_index(lists:sort(Coverage), SrcModules),
-
-    %% Write coverage details for each file
-    lists:foreach(fun({M, _, _}) ->
-                          {ok, _} = cover:analyze_to_file(M, cover_file(M),
-                                                          [html])
-                  end, Coverage),
-
-    Index = filename:join([rebar_utils:get_cwd(), ?EUNIT_DIR, "index.html"]),
-    ?CONSOLE("Cover analysis: ~s\n", [Index]),
-
-    %% Export coverage data, if configured
-    case rebar_config:get(Config, cover_export_enabled, false) of
-        true ->
-            cover_export_coverdata();
-        false ->
-            ok
-    end,
-
-    %% Print coverage report, if configured
-    case rebar_config:get(Config, cover_print_enabled, false) of
-        true ->
-            cover_print_coverage(lists:sort(Coverage));
-        false ->
-            ok
-    end.
-
-cover_close(not_enabled) ->
-    ok;
-cover_close(F) ->
-    ok = file:close(F).
-
-cover_init(false, _BeamFiles) ->
-    {ok, not_enabled};
-cover_init(true, BeamFiles) ->
-    %% Attempt to start the cover server, then set its group leader to
-    %% .eunit/cover.log, so all cover log messages will go there instead of
-    %% to stdout. If the cover server is already started, we'll kill that
-    %% server and start a new one in order not to inherit a polluted
-    %% cover_server state.
-    {ok, CoverPid} = case whereis(cover_server) of
-                         undefined ->
-                             cover:start();
-                         _         ->
-                             cover:stop(),
-                             cover:start()
-                     end,
-
-    {ok, F} = OkOpen = file:open(
-                         filename:join([?EUNIT_DIR, "cover.log"]),
-                         [write]),
-
-    group_leader(F, CoverPid),
-
-    ?INFO("Cover compiling ~s\n", [rebar_utils:get_cwd()]),
-
-    Compiled = [{Beam, cover:compile_beam(Beam)} || Beam <- BeamFiles],
-    case [Module || {_, {ok, Module}} <- Compiled] of
-        [] ->
-            %% No modules compiled successfully...fail
-            ?ERROR("Cover failed to compile any modules; aborting.~n", []),
-            ?FAIL;
-        _ ->
-            %% At least one module compiled successfully
-
-            %% It's not an error for cover compilation to fail partially,
-            %% but we do want to warn about them
-            PrintWarning =
-                fun(Beam, Desc) ->
-                        ?CONSOLE("Cover compilation warning for ~p: ~p",
-                                 [Beam, Desc])
-                end,
-            _ = [PrintWarning(Beam, Desc) || {Beam, {error, Desc}} <- Compiled],
-            OkOpen
-    end;
-cover_init(Config, BeamFiles) ->
-    cover_init(rebar_config:get(Config, cover_enabled, false), BeamFiles).
-
-cover_analyze_mod(Module) ->
-    case cover:analyze(Module, coverage, module) of
-        {ok, {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)]),
-            []
-    end.
-
-is_eunitized(Mod) ->
-    has_eunit_test_fun(Mod) andalso
-        has_header(Mod, "include/eunit.hrl").
-
-has_eunit_test_fun(Mod) ->
-    [F || {exports, Funs} <- Mod:module_info(),
-          {F, 0} <- Funs, F =:= test] =/= [].
-
-has_header(Mod, Header) ->
-    Mod1 = case code:which(Mod) of
-               cover_compiled ->
-                   {file, File} = cover:is_compiled(Mod),
-                   File;
-               non_existing -> Mod;
-               preloaded -> Mod;
-               L -> L
-           end,
-    {ok, {_, [{abstract_code, {_, AC}}]}} = beam_lib:chunks(Mod1,
-                                                            [abstract_code]),
-    [F || {attribute, 1, file, {F, 1}} <- AC,
-          string:str(F, Header) =/= 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, "<!DOCTYPE HTML><html>\n"
-                    "<head><meta charset=\"utf-8\">"
-                    "<title>Coverage Summary</title></head>\n"
-                    "<body>\n"),
-    IsSrcCoverage = fun({Mod,_C,_N}) -> lists:member(Mod, SrcModules) end,
-    {SrcCoverage, TestCoverage} = lists:partition(IsSrcCoverage, Coverage),
-    cover_write_index_section(F, "Source", SrcCoverage),
-    cover_write_index_section(F, "Test", TestCoverage),
-    ok = file:write(F, "</body></html>"),
-    ok = file:close(F).
-
-cover_write_index_section(_F, _SectionName, []) ->
-    ok;
-cover_write_index_section(F, SectionName, Coverage) ->
-    %% Calculate total coverage
-    {Covered, NotCovered} = lists:foldl(fun({_Mod, C, N}, {CAcc, NAcc}) ->
-                                                {CAcc + C, NAcc + N}
-                                        end, {0, 0}, Coverage),
-    TotalCoverage = percentage(Covered, NotCovered),
-
-    %% Write the report
-    ok = file:write(F, ?FMT("<h1>~s Summary</h1>\n", [SectionName])),
-    ok = file:write(F, ?FMT("<h3>Total: ~s</h3>\n", [TotalCoverage])),
-    ok = file:write(F, "<table><tr><th>Module</th><th>Coverage %</th></tr>\n"),
-
-    FmtLink =
-        fun(Module, Cov, NotCov) ->
-                ?FMT("<tr><td><a href='~s.COVER.html'>~s</a></td><td>~s</td>\n",
-                     [Module, Module, percentage(Cov, NotCov)])
-        end,
-    lists:foreach(fun({Module, Cov, NotCov}) ->
-                          ok = file:write(F, FmtLink(Module, Cov, NotCov))
-                  end, Coverage),
-    ok = file:write(F, "</table>\n").
-
-cover_print_coverage(Coverage) ->
-    {Covered, NotCovered} = lists:foldl(fun({_Mod, C, N}, {CAcc, NAcc}) ->
-                                                {CAcc + C, NAcc + N}
-                                        end, {0, 0}, Coverage),
-    TotalCoverage = percentage(Covered, NotCovered),
-
-    %% Determine the longest module name for right-padding
-    Width = lists:foldl(fun({Mod, _, _}, Acc) ->
-                                case length(atom_to_list(Mod)) of
-                                    N when N > Acc ->
-                                        N;
-                                    _ ->
-                                        Acc
-                                end
-                        end, 0, Coverage) * -1,
-
-    %% Print the output the console
-    ?CONSOLE("~nCode Coverage:~n", []),
-    lists:foreach(fun({Mod, C, N}) ->
-                          ?CONSOLE("~*s : ~3s~n",
-                                   [Width, Mod, percentage(C, N)])
-                  end, Coverage),
-    ?CONSOLE("~n~*s : ~s~n", [Width, "Total", TotalCoverage]).
-
-cover_file(Module) ->
-    filename:join([?EUNIT_DIR, atom_to_list(Module) ++ ".COVER.html"]).
-
-cover_export_coverdata() ->
-    ExportFile = filename:join(eunit_dir(), "eunit.coverdata"),
-    case cover:export(ExportFile) of
-        ok ->
-            ?CONSOLE("Coverdata export: ~s~n", [ExportFile]);
-        {error, Reason} ->
-            ?ERROR("Coverdata export failed: ~p~n", [Reason])
-    end.
-
-percentage(0, 0) ->
-    "not executed";
-percentage(Cov, NotCov) ->
-    integer_to_list(trunc((Cov / (Cov + NotCov)) * 100)) ++ "%".
-
-%%
 %% == reset_after_eunit ==
 %%
 
diff --git a/src/rebar_qc.erl b/src/rebar_qc.erl
index 1976722..e08833b 100644
--- a/src/rebar_qc.erl
+++ b/src/rebar_qc.erl
@@ -4,7 +4,7 @@
 %%
 %% rebar: Erlang Build Tools
 %%
-%% Copyright (c) 2011-2012 Tuncer Ayaz
+%% Copyright (c) 2011-2014 Tuncer Ayaz
 %%
 %% Permission is hereby granted, free of charge, to any person obtaining a copy
 %% of this software and associated documentation files (the "Software"), to deal
@@ -68,11 +68,17 @@ info(help, qc) ->
        "  {qc_opts, [{qc_mod, module()}, Options]}~n"
        "  ~p~n"
        "  ~p~n"
+       "  ~p~n"
+       "  ~p~n"
+       "  ~p~n"
        "Valid command line options:~n"
        "  compile_only=true (Compile but do not test properties)",
        [
         {qc_compile_opts, []},
-        {qc_first_files, []}
+        {qc_first_files, []},
+        {cover_enabled, false},
+        {cover_print_enabled, false},
+        {cover_export_enabled, false}
        ]);
 info(help, clean) ->
     Description = ?FMT("Delete QuickCheck test dir (~s)", [?QC_DIR]),
@@ -151,21 +157,40 @@ run(Config, QC, QCOpts) ->
     %% Compile erlang code to ?QC_DIR, using a tweaked config
     %% with appropriate defines, and include all the test modules
     %% as well.
-    {ok, _SrcErls} = rebar_erlc_compiler:test_compile(Config, "qc", ?QC_DIR),
+    {ok, SrcErls} = rebar_erlc_compiler:test_compile(Config, "qc", ?QC_DIR),
 
     case CompileOnly of
         "true" ->
             true = code:set_path(CodePath),
             ?CONSOLE("Compiled modules for qc~n", []);
         false ->
-            run1(QC, QCOpts, CodePath)
+            run1(QC, QCOpts, Config, CodePath, SrcErls)
     end.
 
-run1(QC, QCOpts, CodePath) ->
+run1(QC, QCOpts, Config, CodePath, SrcErls) ->
+
+    AllBeamFiles = rebar_utils:beams(?QC_DIR),
+    AllModules = [rebar_utils:beam_to_mod(?QC_DIR, N)
+                  || N <- AllBeamFiles],
+    PropMods = find_prop_mods(),
+    FilteredModules = AllModules -- PropMods,
+
+    SrcModules = [rebar_utils:erl_to_mod(M) || M <- SrcErls],
+
+    {ok, CoverLog} = rebar_cover_utils:init(Config, AllBeamFiles, qc_dir()),
+
     TestModule = fun(M) -> qc_module(QC, QCOpts, M) end,
-    case lists:flatmap(TestModule, find_prop_mods()) of
+    QCResult = lists:flatmap(TestModule, PropMods),
+
+    rebar_cover_utils:perform_cover(Config, FilteredModules, SrcModules,
+                                    qc_dir()),
+    rebar_cover_utils:close(CoverLog),
+    ok = rebar_cover_utils:exit(),
+
+    true = code:set_path(CodePath),
+
+    case QCResult of
         [] ->
-            true = code:set_path(CodePath),
             ok;
         Errors ->
             ?ABORT("One or more QC properties didn't hold true:~n~p~n",