New lint: always_true_conditions

[Dominic-Moser]

This lint closes #1593

This is my first lint, please let me know if I messed something up anywhere!

changelog: [always_true_conditions]: add new lint

[rustbot]

r? @Alexendoo

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[samueltardieu]

The lintcheck results shows 64 hits, which seem to be all false positives.

[samueltardieu]

@Dominic-Moser Do you plan to continue working on this lint?
@rustbot author

[rustbot]

Reminder, once the PR becomes ready for a review, use @rustbot ready.

[Dominic-Moser]

@rustbot ready, sorry school's been hitting hard

[Dominic-Moser]

never mind, I have to to checks to make sure the same variable is being used throughout the whole expression

[Dominic-Moser]

@samueltardieu I am so confused right now, I keep trying to rebase and it keeps saying I need to rebase. I am sure this is my fault but i have no clue how to fix this...
On the bright side I do actually think that the code works properly now 🫠

[Alexendoo]

Your first commit contains a lot of unrelated changes 9ce8566

What I would do is first reset your branch to the current state of master

git fetch upstream
git reset --hard upstream/master

Then grab the main parts of the PR - the lint and the test file

git checkout b55d82f89c1b29f25044aeaafbbdb7a241c82c3b -- clippy_lints/src/always_true_conditions.rs tests/ui/always_true_conditions.rs

Now you can run cargo dev update_lints, add the lint registration to clippy_lints/src/lib.rs again, and make sure tests pass. Then you can create the commit once more

[Dominic-Moser]

@rustbot ready