Fix crash during deck filtering

[shaiguelman]

Pull Request template

Purpose / Description

Fixes issue where search bar was not filtering properly and crashing the app.

Fixes

Fixes #11877

Approach

Creates a copy of the list of decks before filtering. The error was caused by using the same list in filtering as in the UI. I also made a small optimization of the containsFilterString method as well as added error catching in TypedFilter in case error happens again.

How Has This Been Tested?

Reproduced error using process described in the issue before and after code changes. Screenshot of results after code changes:

Learning (optional, can help others)

Stack overflow post that helped me narrow the issue

Checklist

Please, go through these checks before submitting the PR.

• You have not changed whitespace unnecessarily (it makes diffs hard to read)
• You have a descriptive commit message with a short title (first line, max 50 chars).
• Your code follows the style of the project (e.g. never omit braces in if statements)
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[welcome]

First PR! 🚀 We sincerely appreciate that you have taken the time to propose a change to AnkiDroid! Please have patience with us as we are all volunteers - we will get to this as soon as possible.

[shaiguelman]

Added basic unit tests to ensure filter does not break again. Could probably use a few more to cover more edge cases but figured this was good enough for now

[david-allison]

I love this, thank you!

Revert the publishResults change (or discuss if I'm wrong) and it's good to go

[david-allison]

looks great, thank you so much

[Arthur-Milchior]

I think an explicit call to if results == null would be better. Try are more costly than conditional in general, and anyway clearer.

[shaiguelman]

I've since reverted this code since David said it was better to have it crash

[shaiguelman]

I changed it to use a nullable to avoid an if check

[david-allison]

I think I'd prefer a crash here (AKA no change), as it's an assertion which doesn't hold, but I'll leave the final decision to you. Implementer's choice, I'm happy either way =)

I think the answer to the question of 'what do we do if we get a null' is hard to pin down: do we want all results, or no results?

[shaiguelman]

Yea that's a good question. I did no results since that was simpler to implement but it's not necessarily the best UX choice. It would require a sizeable refactor though to return all results.

I think since we're getting a little outside the scope of the PR I'll revert it to original for now and leave it for a non-urgent issue.

[david-allison]

Thank you!

[github-actions]

Hi there @shaiguelman! This is the OpenCollective Notice for PRs merged from 2022-07-01 through 2022-07-31

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