Added some type hints

[bartekpacia]

Description

I added type hints to (files listed in commit message). I have a few questions though:

• do we want type hints on every single method? Like, make it required?
• if method returns None, should it also be typehinted?

Also, I'm not sure how should I typehint objects returned by TasksListModel.find_by_id().

When a mentors accepts proposed changes and answers questions listed above, I'll be very happy to typehint whole codebase :)

Fixes #331 (as of now, partly)

Type of Change:

• Code
• Documentation

Code/Quality Assurance Only

• New feature (non-breaking change which adds functionality pre-approved by mentors))

How Has This Been Tested?

Type hints don't have runtime impact, but just to make sure I run all the tests. And CI is passing, too.

Checklist:

• My PR follows the style guidelines of this project
• I have performed a self-review of my own code or materials
• I have commented my code or provided relevant documentation, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation

Code/Quality Assurance Only

• My changes generate no new warnings
• My PR currently breaks something (fix or feature that would cause existing functionality to not work as expected)
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[bartekpacia]

@isabelcosta Could I get some feedback and answer to my questions? I'd really like to add those type hints :D

[isabelcosta]

@isabelcosta Could I get some feedback and answer to my questions? I'd really like to add those type hints :D

You can submit the PR with that :) I haven't received any response either, and couldn't bring this to a Community Open Session either. Once I get the chance I'll ask about the community standards, where they stand.

[bartekpacia]

That's great! Thanks for a fast response :)

[isabelcosta]

@bartekpacia as I am catching up on PRs, I noticed this very important issue. I got more informed about this Python feature that I was not aware of and think it would be a great addition to the project.

Since this has so many merge conflicts, would you like to fix them or leave this issue for other contributors? I was thinking of creating sub-issues per file or per feature or per domain, to make this change into type hints easier to manage and review.

What do you think? I am totally fine if you choose not to continue with this and then I'll create smaller issue to make this transition.

[bartekpacia]

@isabelcosta I'll try to fix the conflicts in this PR. You can then open some issues requesting to add type hints to the rest of the project.

[isabelcosta]

Oki! Sounds good @bartekpacia , let me know once you fix it so I can review this :) And then I'll create type hint issues for what is missing.

[bartekpacia]

@isabelcosta Resolved conflicts :)

[isabelcosta]

thank you so much @bartekpacia

[ramitsawhney27]

Very nice, thank you for this, learned something new here!

[isabelcosta]

Looks good :) Thank you so much for proposing this enhancement in the app and implementing part of it here in the PR @bartekpacia 🎉