Add tests to cover what is testable in SelfUpdate command

[stronk7]

Note that only helper methods can be tested for that command, not the execution of the update itself (it has to happen within a PHAR). And it doesn't make much sense to start mocking lots of stuff for that.

Some integration tests @ CIS will be in charge of
covering the real execution instead. Coming soon.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (8124fe7) 84.77% compared to head (a79ed0a) 85.08%.

Additional details and impacted files

@@             Coverage Diff              @@
##               main     #250      +/-   ##
============================================
+ Coverage     84.77%   85.08%   +0.31%     
  Complexity      720      720              
============================================
  Files            75       75              
  Lines          2226     2226              
============================================
+ Hits           1887     1894       +7     
+ Misses          339      332       -7     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[stronk7]

Thanks @kabalin,

I'm going to keep this on hold until we have a couple of releases with the self-update command working. Only then we'll be able to add some integration (GHA) test to verify that it's working as expected.

Ciao :-)

[stronk7]

Ok, now that we have > 2 releases supporting the selfupdate command, we can add some simple integration tests for it.

I've added a second commit that just:

• downloads the 4.1.8 (first version with the command working) moodle-plugin-ci.phar asset.
• runs selfupdate to become updated to actual.
• runs selfupdate --rollback to go back to the original 4.1.8.

They seem to be passing... so I'm going to make this PR ready for review, it includes both the original unit tests and the new integration tests.

Ciao :-)

[stronk7]

I'm sef-merging this upstream now, just to have the selfupdate command covered and detect any potential regression, specifically when bumping various components versions.

Ciao .-)