forked from eproxus/meck
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Record cover data on passtrhough calls
If a module with cover instrumentation is mocked then make sure to instrument any passtrhough calls. This way coverage analysis is still available for passtrhough calls. This functionality can be disabled via the `no_passthrough_cover` option. Implementation Details ---------------------- This is coded for the specific use case of running eunit tests from rebar with coverage analysis enabled. Previously, if just some of the functions in a src module were mocked then all coverage analyis on said module, while it was mocked, was lost. 1. check if module is instrumented for coverage 2. compile `<name>_meck_original` (thus known as `OriginalMod`) and then cover compile it 3. let meck do it's thing 4. during unload/termination of mocked module make sure to first export the cover data collected on `OriginalMod`, after exporting modify the data to use the real modules name (e.g. `foo_meck_original` -> `foo`), this way the data can be imported and counted against `foo` 5. let meck do it's usual cleanup 6. during restore import the `OriginalMod` coverage data Tricks are played with cover's BEAM code so that private functions can be called. This was done to avoid creating temporary files and copy/pasting code from cover.
- Loading branch information
Showing
4 changed files
with
242 additions
and
20 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,109 @@ | ||
| %%============================================================================== | ||
| %% Licensed under the Apache License, Version 2.0 (the "License"); | ||
| %% you may not use this file except in compliance with the License. | ||
| %% You may obtain a copy of the License at | ||
| %% | ||
| %% http://www.apache.org/licenses/LICENSE-2.0 | ||
| %% | ||
| %% Unless required by applicable law or agreed to in writing, software | ||
| %% distributed under the License is distributed on an "AS IS" BASIS, | ||
| %% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
| %% See the License for the specific language governing permissions and | ||
| %% limitations under the License. | ||
| %%============================================================================== | ||
|
|
||
| %% @doc Module containing functions needed by meck to integrate with cover. | ||
|
|
||
| -module(meck_cover). | ||
|
|
||
| %% Interface exports | ||
| -export([compile_beam/2]). | ||
| -export([rename_module/2]). | ||
|
|
||
| %%============================================================================== | ||
| %% Interface exports | ||
| %%============================================================================== | ||
|
|
||
| %% @doc Enabled cover on `<name>_meck_original'. | ||
| compile_beam(OriginalMod, Bin) -> | ||
| alter_cover(), | ||
| {ok, _} = cover:compile_beam(OriginalMod, Bin). | ||
|
|
||
| %% @doc Given a cover file `File' exported by `cover:export' overwrite | ||
| %% the module name with `Name'. | ||
| rename_module(File, Name) -> | ||
| NewTerms = change_cover_mod_name(read_cover_file(File), Name), | ||
| write_terms(File, NewTerms), | ||
| ok. | ||
|
|
||
| %%============================================================================== | ||
| %% Internal functions | ||
| %%============================================================================== | ||
|
|
||
| %% @private | ||
| %% | ||
| %% @doc Alter the cover BEAM module to export some of it's private | ||
| %% functions. This is done for two reasons: | ||
| %% | ||
| %% 1. Meck needs to alter the export analysis data on disk and | ||
| %% therefore needs to understand this format. This is why `get_term' | ||
| %% and `write' are exposed. | ||
| %% | ||
| %% 2. In order to avoid creating temporary files meck needs direct | ||
| %% access to `compile_beam/2' which allows passing a binary. | ||
| alter_cover() -> | ||
| case lists:member({compile_beam,2}, cover:module_info(exports)) of | ||
| true -> | ||
| ok; | ||
| false -> | ||
| Beam = meck_mod:beam_file(cover), | ||
| AbsCode = meck_mod:abstract_code(Beam), | ||
| Exports = [{compile_beam, 2}, {get_term, 1}, {write, 2}], | ||
| AbsCode2 = meck_mod:add_exports(Exports, AbsCode), | ||
| meck_mod:compile_and_load_forms(AbsCode2) | ||
| end. | ||
|
|
||
| change_cover_mod_name(CoverTerms, Name) -> | ||
| {_, Terms} = lists:foldl(fun change_name_in_term/2, {Name,[]}, CoverTerms), | ||
| Terms. | ||
|
|
||
| change_name_in_term({file, Mod, File}, {Name, Terms}) -> | ||
| Term2 = {file, Name, replace_string(File, Mod, Name)}, | ||
| {Name, [Term2|Terms]}; | ||
| change_name_in_term({Bump={bump,_,_,_,_,_},_}=Term, {Name, Terms}) -> | ||
| Bump2 = setelement(2, Bump, Name), | ||
| Term2 = setelement(1, Term, Bump2), | ||
| {Name, [Term2|Terms]}; | ||
| change_name_in_term({_Mod,Clauses}, {Name, Terms}) -> | ||
| Clauses2 = lists:foldl(fun change_name_in_clause/2, {Name, []}, Clauses), | ||
| Term2 = {Name, Clauses2}, | ||
| {Name, [Term2|Terms]}. | ||
|
|
||
| change_name_in_clause(Clause, {Name, NewClauses}) -> | ||
| {Name, [setelement(1, Clause, Name)|NewClauses]}. | ||
|
|
||
| replace_string(File, Old, New) -> | ||
| Old2 = atom_to_list(Old), | ||
| New2 = atom_to_list(New), | ||
| re:replace(File, Old2, New2, [{return, list}]). | ||
|
|
||
| read_cover_file(File) -> | ||
| {ok, Fd} = file:open(File, [read, binary, raw]), | ||
| Terms = get_terms(Fd, []), | ||
| file:close(Fd), | ||
| Terms. | ||
|
|
||
| get_terms(Fd, Terms) -> | ||
| case cover:get_term(Fd) of | ||
| eof -> Terms; | ||
| Term -> get_terms(Fd, [Term|Terms]) | ||
| end. | ||
|
|
||
| write_terms(File, Terms) -> | ||
| {ok, Fd} = file:open(File, [write, binary, raw]), | ||
| lists:map(write_term(Fd), Terms), | ||
| ok. | ||
|
|
||
| write_term(Fd) -> | ||
| fun(Term) -> cover:write(Term, Fd) end. | ||
|
|
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters