Code coverage and phpunit: xdebug extension missing

[scara]

Today, while scripting a test case in sebastianbergmann/phpunit#2844 (comment), I realized that here the xdebug extension is missing.

This extension could slow down the moodle docker environment so it should be provided disabled by default and enabled only when required e.g. for the phpunit code coverage.

[danpoltawski]

+1 to the suggestion and way to implement it

[andrewnicols]

+1 here too.

[caperneoignis]

I actually made these as too separate images, one with xdebug and one with out for every php version. I added a ARG to the docker file and in the travis test I add an additional env variable to the build, then tag the docker image with '_xdebug'. So php7.2 or 7.1 would be the normal files, and then if you want xdebug it would be 7.2_xdebug etc.

[caperneoignis]

I also add an additional item in the test file to test for xdebug if the env value is set during the test process.

[scara]

Hi @caperneoignis,
would you like to contribute here an enhanced version w/ xdebug compiled but disabled and enabled only via an env var passed to the image?
We cannot double the images, for maintenance purposes.

Otherwise, in my spare time I'll create a PR.
Let me (us) know.

TIA,
Matteo

[caperneoignis]

Oh, I forgot you'll don't use travis to push the images. Because the tagging is handled by travis in my case. Let me take a look because disabling/enabling it on the fly when the image is started is tricky without a pre-built php.ini file to load with a string that can be replaced by a SED function. That's why I just have two images that are built by travis and have travis tag them in the job.

[scara]

Hello Everyone,
a new PR landed to address this issue, #102, which requires re-building the image.

I'm still voting #31, but we should take into account non-root usage, #1, which could prevent to write the xdebug ini file where it should be so #102 could be an interesting option.

HTH,
Matteo

[andrewnicols]

I'm voting against this. There is no need to use xdebug for code coverage when there are better solutions available which do not require the installation of extensions.

[caperneoignis]

@andrewnicols generally curious, what solution are you referring too that can be added on the fly and will work in the same fashion as xdebug, using the same files that Moodle outputs during test setup, and similar output? Or is the solution you are referring to take additional steps to setup?

[rezaies]

+1

[andrewnicols]

@caperneoignis, I’m referring to phpdbg which is the pho debugger which comes as a part of PHP since 7.0. It’s faster than xdebug for code coverage generation and has feature parity for that purpose. So for code coverage please use phpdbg. If you want to perform debugging on the fly then you should build your own image based on ours. Adding xdebug will slow the test runs for every other person with very little benefit for the majority of people.

[scara]

Hi @andrewnicols,
for the purpose of this issue I'm fine w/ your last sentence since a comment from @kabalin in moodlehq/moodle-docker#111 (comment).
Not sure why I was not able to collect coverage at the time of opening this issue though.

Since that time someone developing on top of Moodle HQ Docker Toolbox is asking for xdebug for more than the purpose of this issue.

Here is my proposal:

1. [me] try to recap why I was not able to performe the coverage
2. document it
3. document how to extend the image

Both (2) and (3) in the README via PR.

HTH,
Matteo