Lint: filter(Option::is_some).map(Option::unwrap)
Fixes#6061
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog:
* add new lint for filter(Option::is_some).map(Option::unwrap)
First Rust PR, so I'm sure I've violated some idioms. Happy to change anything.
I'm getting one test failure locally -- a stderr diff for `compile_test`. I'm having a hard time seeing how I could be causing it, so I'm tentatively opening this in the hopes that it's an artifact of my local setup against `rustc`. Hoping it can at least still be reviewed in the meantime.
I'm gathering that since this is a method lint, and `.filter(...).map(...)` is already checked, the means of implementation needs to be a little different, so I didn't exactly follow the setup boilerplate. My way of checking for method calls seems a little too direct (ie, "is the second element of the expression literally the path for `Option::is_some`?"), but it seems like that's how some other lints work, so I went with it. I'm assuming we're not concerned about, eg, closures that just end up equivalent to `Option::is_some` by eta reduction.
Lint on `_.clone().method()` when method takes self by value
Set applicability correctly
Correct suggestion when the cloned value is a macro call. e.g. `m!(x).clone()`
Don't lint when not using the `Clone` trait
Ignore str::len() in or_fun_call lint.
changelog: Changed `or_fun_call` to ignore `str::len`, in the same way it ignores `slice::len` and `array::len`
Closes#6943
Refactor lints in methods module
This PR refactors methods lints other than the lints I refactored in https://github.com/rust-lang/rust-clippy/pull/6826 and moves some functions to methods/utils.rs.
Basically, I follow the instruction described in #6680.
**For ease of review, I refactored step by step, keeping each commit small.**
closes https://github.com/rust-lang/rust-clippy/issues/6886
cc: `@phansch,` `@flip1995,` `@Y-Nak`
changelog: Move lints in methods module to their own modules and some function to methods/utils.rs.
wrong_self_convention: fix lint in case of `to_*_mut` method
fixes#6758
changelog: wrong_self_convention: fix lint in case of `to_*_mut` method. When a method starts with `to_` and ends with `_mut`, clippy expects a `&mut self` parameter, otherwise `&self`.
Any feedback is welcome. I was also thinking if shouldn't we treat `to_` the same way as `as_`. Namely to accept `self` taken: `&self` or `&mut self`.
