feat: lint unchecked subtraction of a 'Duration' from an 'Instant'
Hello all, I tried to tackle the open issue #9371 and this is what I came up with.
I have a difficulty currently - some tests are failing:
```
failures:
[ui] ui/manual_instant_elapsed.rs
```
The `manual_instant_elapsed` is failing because of `Instant::now() - duration` test, this now gets also picked by `unchecked_duration_subtraction` lint.
What is the correct way to proceed in this case? Simply update the `.stderr` file for `manual_instant_elapsed` lint?
changelog: [`unchecked_duration_subtraction`]: Add lint for unchecked subtraction of a `Duration` from an `Instant`.
fixes#9371
Add `manual_is_ascii_check` lint
Addresses https://github.com/rust-lang/rust-clippy/issues/9290
This PR adds new lint `manual_is_ascii_check`, which detects comparison with ascii ranges using `matches!` macros.
As I mentioned as following in the Issue;
> Yes, that's true. we'll start small and then grow it.
> So I'll try to handle matches! macro with single range as suggested above.
However during writing first version, I was thinking that the changes to support alphabetic and digits will be small patch, so I made a single PR in hope review cost can be reduced.
changelog: add new lint [`manual_is_ascii_check`]
r? `@xFrednet`
Changelog for Rust 1.65
Roses are red,
violets are blue,
another 6 weeks,
another changelog, yahoo!
This did not rhyme,
luckily, not a crime.
I want to say something smart,
but I am out of time.
---
Note for the reviewer. This PR is written, as if Rust was already released on 2022-11-03. Please review the changes and approve if you agree, but only merge it after the release. :)
---
changelog: none
Add lint for confusing use of `^` instead of `.pow`
fixes#4205
Adds a lint named [`confusing_xor_and_pow`], it warns the user when `a ^ b` is used as the `.pow()` function, it doesn't warn for Hex, Binary... etc.
---
changelog: New lint: [`confusing_xor_and_pow`]
add new lint `seek_to_start_instead_of_rewind `
changelog: `seek_to_start_instead_of_rewind`: new lint to suggest using `rewind` instead of `seek` to start
Resolve#8600
Add `unused_format_specs` lint
Currently catches two cases:
An empty precision specifier:
```rust
// the same as {}
println!("{:.}", x);
```
And using formatting specs on `format_args!()`:
```rust
// prints `x.`, not `x .`
println("{:5}.", format_args!("x"));
```
changelog: new lint: [`unused_format_specs`]
Add `manual_filter` lint for `Option`
Share much of its implementation with `manual_map` and should greatly benefit from its previous feedback.
I'm sure it's possible to even more refactor both and would gladly take input on that as well as any clippy idiomatic usage, since this is my first lint addition.
I've added the lint to the complexity section for now, I don't know if every new lint needs to go in nursery first.
The matching could be expanded to more than `Some(<value>)` to lint on arbitrary struct matching inside the `Some` but I've left it like it was for `manual_map` for now. `needless_match::pat_same_as_expr` provides a more generic match example.
close https://github.com/rust-lang/rust-clippy/issues/8822
changelog: Add lint [`manual_filter`] for `Option`
This lint detects calls to a `&self`-taking `as_ptr` method, where
the result is then immediately cast to a `*mut T`. Code like this
is probably invalid, as that pointer will not have write permissions,
and `*mut T` is usually used to write through.
add `box-default` lint
This adds a `box-default` lint to suggest using `Box::default()` instead of `Box::new(Default::default())`, which offers less moving parts and potentially better performance according to [the perf book](https://nnethercote.github.io/perf-book/standard-library-types.html#box).
---
changelog: add [`box_default`] lint
Implement https://github.com/rust-lang/rust-clippy/issues/8368 - a new
lint to inline format arguments such as `print!("{}", var)` into
`print!("{var}")`.
code | suggestion | comment
---|---|---
`print!("{}", var)` | `print!("{var}")` | simple variables
`print!("{0}", var)` | `print!("{var}")` | positional variables
`print!("{v}", v=var)` | `print!("{var}")` | named variables
`print!("{0} {0}", var)` | `print!("{var} {var}")` | aliased variables
`print!("{0:1$}", var, width)` | `print!("{var:width$}")` | width
support
`print!("{0:.1$}", var, prec)` | `print!("{var:.prec$}")` | precision
support
`print!("{:.*}", prec, var)` | `print!("{var:.prec$}")` | asterisk
support
code | suggestion | comment
---|---|---
`print!("{0}={1}", var, 1+2)` | `print!("{var}={0}", 1+2)` | Format
string uses an indexed argument that cannot be inlined. Supporting this
case requires re-indexing of the format string.
changelog: [`uninlined_format_args`]: A new lint to inline format
arguments, i.e. `print!("{}", var)` into `print!("{var}")`
This is done because `to_owned` is very similarly named to `into_owned`, but the
effect of calling those two methods is completely different. This creates
confusion (stemming from the ambiguity of the 'owned' term in the context of
`Cow`s) and might not be what the writer intended.
new lint
This fixes#6576
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`
---
changelog: add [`multi_assignments`] lint
Lint `collapsible_str_replace`
fixes#6651
```
changelog: [`collapsible_str_replace`]: create new lint `collapsible_str_replace`
```
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
- \[ ] Executed `cargo dev update_lints`
- \[x] Added lint documentation
- \[x] Run `cargo dev fmt`
