Add lint for maps with zero-sized value types
Hi, this is my first time contributing to clippy or rust in general, so I'm not sure about the details of contributing. Please excuse me and let me now if I did anything wrong. I have a couple of questions:
1. I'm not sure what category this lint should be. I've put it in "nursery" for now.
1. Should I squash commits this is reviewed/merged?
changelog: Add lint for maps with zero-sized value types
Fixes#1641
Add --no-deps option to avoid running on path dependencies in workspaces
Since rust-lang/cargo#8758 has hit nightly, this allows us to address the second bullet point and [the concern related to `--fix`](https://github.com/rust-lang/cargo/issues/8143#issuecomment-619289546) in the [RUSTC_WORKSPACE_WRAPPER tracking issue](https://github.com/rust-lang/cargo/issues/8143).
As a reminder stabilizing that env var will solve #4612 (Clippy not running after `cargo check` in stable) and would allow to stabilize the `--fix` option in Clippy.
changelog: Add `--no-deps` option to avoid running on path dependencies in workspaces
Fixes#3025
Add lint print_stderr
Resolves#6348
Almost identical to print_stdout, this lint applies to the `eprintln!` and `eprint!` macros rather than `println!` and `print!`.
changelog: Add new lint [`print_stderr`]. [`println_empty_string`] and [`print_with_newline`] now apply to `eprint!()` and `eprintln!()` respectively.
Added a lint-fraction-readability flag to the configuration
This adds an option to disable the `unreadable_literal` lint for floats with a longer fraction. This allows users to write `0.100200300` without getting a warning. Fixes#4176
I have some open questions about this PR:
1. I've named the option `lint-fraction-readability` is this a good name or should I rename it to something else?
2. What should the default configuration value be?
* The current default value is `true` as this was also the previous default.
3. Do I have to document this new option somewhere else or will it be extracted from the code comment?
4. The current fix option will also rewrite the fraction if the integer part violates the `unreadable_literal` lint it would otherwise also trigger the `inconsistent_digit_grouping` lint. Is this also okay?
* `1.100200300` will be unaffected by the fix function
* `100200300.100200300` will be effected and fixed to `100_200_300.100_200_300`
---
The project needed some getting used to but I'm happy with the result. A big thank you to `@flip1995` for giving me some pointers for this implementation and to everyone for the great introduction documentation!
---
changelog: Added the `unreadable-literal-lint-fractions` configuration to disable the `unreadable_literal` lint for fractions
Moved map_err_ignore to restriction and updated help message
This MR moves map_err_ignore lint from `pedantic` to the `restriction` category of lints and updates the help message to give the user an option to ignore the lint by naming the closure variable e.g. `.map_err(|_ignored| ...`
---
changelog: move map_err_ignore to restriction category
Add lint size_of_in_element_count
Fixes#6381
changelog: Add lint to check for using size_of::<T> or size_of_val::<T> in the count parameter to ptr::copy or ptr::copy_nonoverlapping, which take a count of Ts (And not a count of bytes)
- \[X] Followed [lint naming conventions][lint_naming]
- \[X] Added passing UI tests (including committed `.stderr` file)
- \[ ] `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
Running `cargo test` locally fails with this error:
```
running 1 test
test fmt ... FAILED
failures:
---- fmt stdout ----
status: exit code: 1
stdout:
stderr: error: unable to unlink old fallback exe
error: caused by: Access is denied. (os error 5)
thread 'fmt' panicked at 'Formatting check failed. Run `cargo dev fmt` to update formatting.', tests\fmt.rs:32:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
failures:
fmt
test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out
```
But I did run `cargo dev fmt`
Specifically ptr::{sub, wrapping_sub, add, wrapping_add, offset, wrapping_offset} and slice::{from_raw_parts, from_raw_parts_mut}
The lint now also looks for size_of calls through casts (Since offset takes an isize)
Also fix review comments:
- Use const arrays and iterate them for the method/function names
- merge 2 if_chain's into one using a rest pattern
- remove unnecessary unsafe block in test
And make the lint only point to the count expression instead of the entire function call
Add Collapsible match lint
changelog: Add collapsible_match lint
Closes#1252Closes#2521
This lint finds nested `match` or `if let` patterns that can be squashed together. It is designed to be very conservative to only find cases where merging the patterns would most likely reduce cognitive complexity.
Example:
```rust
match result {
Ok(opt) => match opt {
Some(x) => x,
_ => return,
}
_ => return,
}
```
to
```rust
match result {
Ok(Some(x)) => x,
_ => return,
}
```
These criteria must be met for the lint to fire:
* The inner match has exactly 2 branches.
* Both the outer and inner match have a "wild" branch like `_ => ..`. There is a special case for `None => ..` to also be considered "wild-like".
* The contents of the wild branches are identical.
* The binding which "links" the matches is never used elsewhere.
Thanks to the hir, `if let`'s are easily included with this lint since they are desugared into equivalent `match`'es.
I think this would fit into the style category, but I would also understand changing it to pedantic.
