New Lint: inspect_then_for_each
**Work In Progress**
This PR addresses [Issue 5209](https://github.com/rust-lang/rust-clippy/issues/5209) and adds a new lint called `inspect_then_for_each`.
Current seek some guidance.
If you added a new lint, here's a checklist for things that will be
checked during review or continuous integration.
- \[x] Followed [lint naming conventions][lint_naming]
- \[x] Added passing UI tests (including committed `.stderr` file)
- \[x] `cargo test` passes locally
- \[x] Executed `cargo dev update_lints`
- \[x] Added lint documentation
- \[x] Run `cargo dev fmt`
[lint_naming]: https://rust-lang.github.io/rfcs/0344-conventions-galore.html#lints
---
changelog: Add [`inspect_for_each`] lint for the use of `inspect().for_each()` on `Iterators`.
Add a note to `as_conversions`
I have seen a couple of examples where there are some misunderstandings of `as_conversions` ([1](https://github.com/rust-lang/rust-clippy/issues/5890#issuecomment-671852546), [2](https://github.com/rust-lang/rust-clippy/issues/6116#issuecomment-704251710) and [3](https://github.com/rust-lang/rust-clippy/issues/6428)). This PR adds the note that explains its purpose and relationship with other `as` related casts. Open question: should I list every related lints for discoverbility, or just suggest how to find these? I chose the former because there's no way to list only and all `as` related lints (e.g. on All the Clippt Lints, 'cast' includes some noises, but `cast_` excludes some) even though I cannot guarantee the list will be updated to include future changes.
---
changelog: Add a note to the document of `as_conversions`
New lint: redundant_slicing
changelog: Added lint: `redundant_slicing`
fixes#6519
This will trigger on any type which implements `Index<RangeFull>` that returns the input type. This would be a false positive if the implementation does something other than return itself, but I'm not sure why you would ever want to do that.
Fix the ICE 6539
Fixes#6539
It happened because `zero_sized_map_values` used `layout_of` with types from type aliases, which is essentially the same as the ICE 4968.
---
changelog: Fix an ICE in `zero_sized_map_values`
Fix FP with empty return for `needless_return` lint
This fixes a false positive in `needless_return` lint, when triggered in a closure using `return` statement without value.
Fixes: #6501
changelog: none
Case sensitive file extensions
Closes#6425
Looks for ends_with methods calls with case sensitive extension comparisons.
changelog: Add new lint that warns about case-sensitive file extension comparisons.
Rework diagnostics for wrong number of generic args (fixes#66228 and #71924)
This PR reworks the `wrong number of {} arguments` message, so that it provides more details and contextual hints.
This makes it possible to pass the `Impl` directly to functions, instead
of having to pass each of the many fields one at a time. It also
simplifies matches in many cases.
Roadmap for 2021
[Rendered](https://github.com/flip1995/rust-clippy/blob/roadmap/doc/roadmap-2021.md)
This is the first time Clippy gets its own roadmap. The reason for this roadmap is, that with the Rust language growing, also Clippy is growing. With this keeping track of and implementing bigger projects gets quite hard. This roadmap should help in exactly this regard.
After having the approval of this roadmap by the Clippy team, we want to know from the community:
- What do you think in general about this roadmap?
- Are there any pain points in Clippy, that should be included here?
- What of the points listed here has the highest priority for you?
We're looking forward to getting your feedback!
changelog: Add roadmap for Clippy 2021
r? `@rust-lang/clippy`
Catch `pointer::cast` too in `cast_ptr_alignment`
Fixes#4708
Although there were some discussion in the issue, this PR implements the original feature. I think `cast_ptr_alignment` should exist as it is, separated from `ptr_as_ptr`.
---
changelog: Extend `cast_ptr_alignment` lint for the `pointer::cast` method
Change env var used for testing Clippy
This changes the variable used for testing Clippy in the internal test
suite:
```
CLIPPY_TESTS -> __CLIPPY_INTERNAL_TESTS
```
`CLIPPY_TESTS` is understandably used in environments of Clippy users,
so we shouldn't use it in our test suite.
changelog: Fix oversight which caused Clippy to lint deps in some environments.
Once again fixes https://github.com/rust-lang/rust-clippy/issues/3874
Fix FP for `boxed_local` lint in default trait fn impl
Fix FP on default trait function implementation on `boxed_local` lint.
Maybe I checked too much when looking if `self` is carrying `Self` in its bound type.
I can't find a good test case for this, so it could be too much conservative.
Let me know if you think only detecting `self` parameter is enough.
Fixes: #4804
changelog: none
