refactor `rebar_erlc_compiler`

* modify compiler interface to work on either application objects or
  directories containing source files
* compile all sources in `src_dirs` to the application `ebin` dir and
  all sources in `extra_src_dirs` to a directory mirroring it's
  position in the app's `_build` directory. for example, `apps/foo/more`
  would compile to `_build/default/lib/foo/more`
  for `extra_src_dirs` in the root of a project with multiple
  applications (so orphan directories that don't "belong" to an
  application) compile to `_build/default/extras/more`
* copy directories specified in `extra_src_dirs` into the `_build`
  directory so tools like `ct` and `xref` that expect source to be
  in a particular location still work
* clean compiled artifacts from all `extra_src_dirs`
* alter `eunit`, `ct` and `cover` to work with the new directory
  structure
* billions of new tests

1 files changed, 87 insertions, 0 deletions

diff --git a/test/rebar_cover_SUITE.erl b/test/rebar_cover_SUITE.erl
index 1fae92c..ba078c2 100644
--- a/test/rebar_cover_SUITE.erl
+++ b/test/rebar_cover_SUITE.erl
@@ -7,6 +7,9 @@
          all/0,
          flag_coverdata_written/1,
          config_coverdata_written/1,
+         basic_extra_src_dirs/1,
+         release_extra_src_dirs/1,
+         root_extra_src_dirs/1,
          index_written/1,
          flag_verbose/1,
          config_verbose/1]).
@@ -29,6 +32,8 @@ init_per_testcase(_, Config) ->
 
 all() ->
     [flag_coverdata_written, config_coverdata_written,
+     basic_extra_src_dirs, release_extra_src_dirs,
+     root_extra_src_dirs,
      index_written,
      flag_verbose, config_verbose].
 
@@ -62,6 +67,88 @@ config_coverdata_written(Config) ->
 
     true = filelib:is_file(filename:join([AppDir, "_build", "test", "cover", "eunit.coverdata"])).
 
+basic_extra_src_dirs(Config) ->
+    AppDir = ?config(apps, Config),
+
+    Name = rebar_test_utils:create_random_name("cover_extra_"),
+    Vsn = rebar_test_utils:create_random_vsn(),
+    rebar_test_utils:create_eunit_app(AppDir, Name, Vsn, [kernel, stdlib]),
+
+    ExtraSrc = io_lib:format("-module(~ts_extra).\n-export([ok/0]).\nok() -> ok.\n", [Name]),
+
+    ok = filelib:ensure_dir(filename:join([AppDir, "extra", "dummy"])),
+    ok = file:write_file(filename:join([AppDir, "extra", io_lib:format("~ts_extra.erl", [Name])]),
+                         ExtraSrc),
+
+    RebarConfig = [{erl_opts, [{d, some_define}]}, {extra_src_dirs, ["extra"]}],
+    rebar_test_utils:run_and_check(Config,
+                                   RebarConfig,
+                                   ["eunit", "--cover"],
+                                   {ok, [{app, Name}]}),
+
+    Mod = list_to_atom(lists:flatten(io_lib:format("~ts_extra", [Name]))),
+    {file, _} = cover:is_compiled(Mod).
+
+release_extra_src_dirs(Config) ->
+    AppDir = ?config(apps, Config),
+
+    Name1 = rebar_test_utils:create_random_name("relapp1_"),
+    Vsn1 = rebar_test_utils:create_random_vsn(),
+    rebar_test_utils:create_app(filename:join([AppDir, "apps", Name1]), Name1, Vsn1, [kernel, stdlib]),
+
+    Name2 = rebar_test_utils:create_random_name("relapp2_"),
+    Vsn2 = rebar_test_utils:create_random_vsn(),
+    rebar_test_utils:create_app(filename:join([AppDir, "apps", Name2]), Name2, Vsn2, [kernel, stdlib]),
+
+    ExtraOne = io_lib:format("-module(~ts_extra).\n-export([ok/0]).\nok() -> ok.\n", [Name1]),
+
+    ok = filelib:ensure_dir(filename:join([AppDir, "apps", Name1, "extra", "dummy"])),
+    ok = file:write_file(filename:join([AppDir, "apps", Name1, "extra",
+                                        io_lib:format("~ts_extra.erl", [Name1])]),
+                         ExtraOne),
+
+    ExtraTwo = io_lib:format("-module(~ts_extra).\n-export([ok/0]).\nok() -> ok.\n", [Name2]),
+
+    ok = filelib:ensure_dir(filename:join([AppDir, "apps", Name2, "extra", "dummy"])),
+    ok = file:write_file(filename:join([AppDir, "apps", Name2, "extra",
+                                        io_lib:format("~ts_extra.erl", [Name2])]),
+                         ExtraTwo),
+
+    RebarConfig = [{erl_opts, [{d, some_define}]}, {extra_src_dirs, ["extra"]}],
+    rebar_test_utils:run_and_check(Config,
+                                   RebarConfig,
+                                   ["eunit", "--cover"],
+                                   {ok, [{app, Name1}, {app, Name2}]}),
+
+    Mod1 = list_to_atom(lists:flatten(io_lib:format("~ts_extra", [Name1]))),
+    {file, _} = cover:is_compiled(Mod1),
+    Mod2 = list_to_atom(lists:flatten(io_lib:format("~ts_extra", [Name2]))),
+    {file, _} = cover:is_compiled(Mod2).
+
+root_extra_src_dirs(Config) ->
+    AppDir = ?config(apps, Config),
+
+    Name1 = rebar_test_utils:create_random_name("relapp1_"),
+    Vsn1 = rebar_test_utils:create_random_vsn(),
+    rebar_test_utils:create_app(filename:join([AppDir, "apps", Name1]), Name1, Vsn1, [kernel, stdlib]),
+
+    Name2 = rebar_test_utils:create_random_name("relapp2_"),
+    Vsn2 = rebar_test_utils:create_random_vsn(),
+    rebar_test_utils:create_app(filename:join([AppDir, "apps", Name2]), Name2, Vsn2, [kernel, stdlib]),
+
+    Extra = <<"-module(extra).\n-export([ok/0]).\nok() -> ok.\n">>,
+
+    ok = filelib:ensure_dir(filename:join([AppDir, "extra", "dummy"])),
+    ok = file:write_file(filename:join([AppDir, "extra", "extra.erl"]), Extra),
+
+    RebarConfig = [{erl_opts, [{d, some_define}]}, {extra_src_dirs, ["extra"]}],
+    rebar_test_utils:run_and_check(Config,
+                                   RebarConfig,
+                                   ["eunit", "--cover"],
+                                   {ok, [{app, Name1}, {app, Name2}]}),
+
+    {file, _} = cover:is_compiled(extra).
+
 index_written(Config) ->
     AppDir = ?config(apps, Config),