Make tests null safe

[LuisDuarte1]

Closes #513

This also updates flutter and dart sdk (because newer versions of mockito need it).

Review checklist

• Terms and conditions reflect the current change
• Contains enough appropriate tests
• If aimed at production, writes a new summary in whatsnew/whatsnew-pt-PT
• Properly adds an entry in changelog.md with the change
• If PR includes UI updates/additions, its description has screenshots
• Behavior is as expected
• Clean, well-structured code

[codecov]

Codecov Report

Merging #904 (006e281) into develop (078d9e3) will increase coverage by 1%.
Report is 10 commits behind head on develop.
The diff coverage is 29%.

Additional details and impacted files

@@          Coverage Diff           @@
##           develop   #904   +/-   ##
======================================
+ Coverage       22%    22%   +1%     
======================================
  Files          136    136           
  Lines         3532   3536    +4     
======================================
+ Hits           746    760   +14     
+ Misses        2786   2776   -10     

[Process-ing]

LGTM!

[bdmendes]

Haven't got a chance to review this thoroughly, but for now do not forget to update the flutter version in the deploy action too

[LuisDuarte1]

Haven't got a chance to review this thoroughly, but for now do not forget to update the flutter version in the deploy action too

It was already done

[bdmendes]

It's still 3.7.2 here, am I missing something?

[LuisDuarte1]

It's still 3.7.2 here, am I missing something?

Sorry I forgot to push ahahah done

[bdmendes]

1. Should we add documentation about the build runner step in uni/README.md?
2. Should we exclude *.mocks.dart from linting and coverage analyzers?

[LuisDuarte1]

1. Should we add documentation about the build runner step in uni/README.md?

I agree I'll do it, and maybe in the future we should write proper documentation on how to write tests on flutter, to help future contributors, but it should be done separately.

2. Should we exclude *.mocks.dart from linting and coverage analyzers?

Not sure if coverage will be affected, since the coverage should only be analyzed in the lib/ folder. But I'll change the format/linting ones

[bdmendes]

I'll make sure to write something about testing in my presentation slides later this September. We can then base the proper docs on it

[bdmendes]

Quick grammar police before getting this merged

[bdmendes]

Good to go 🚀