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`.
New lint: vec_init_then_push
fixes: #1483
This will trigger on `new`, `default`, and `with_capacity` when the given capacity is less than or equal to the number of push calls. Is there anything else this should trigger on?
changelog: Added lint: `vec_init_then_push`
This splits up clippy::collapsible_if into collapsible_if for
if x {
if y { }
}
=>
if x && y { }
and collapsible_else_if for
if x {
} else {
if y { }
}
=>
if x {
} else if y {
}
so that we can lint for only the latter but not the first if we desire.
changelog: collapsible_if: split up linting for if x {} else { if y {} } into collapsible_else_if lint
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.
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
run `cargo dev new_lint --category correctness --name suspicious_chained_operators --pass early`
add (currently failing) tests for suspicious_chained_operators
add some tests to answer a question that came up during implementation
write usage code for functions we'll need to find or create
Complete left-right tracking TODO
get it compiling with several `todo!` invocations.
refactor to a set of incomplete functions that don't expect to be able to edit a `Span`
create placeholder for `suggestion_with_swapped_ident` function and correct some comments
add `inside_larger_boolean_expression` test
fill out `get_ident` and `suggestion_with_swapped_ident`
Implementi the `IdentIter`
start on implementing the `IdentIter`
handle the `ExprKind::Path` case in `IdentIter`
on second thought, make the iterator type dynamic so we don't need an explicit type for each one we will need
handle `ExprKind::MacCall` in `IdentIter`
Try handling `box x` expressions
restructure `IdentIter`
set `self.done` when returning `None`
Handle `ExprKind::Array`
reduce duplication with a macro that we expect to use several more times
handle ExprKind::Call
add `new_p` convenience method
handle `MethodCall`
handle `Tup` and `Binary`
handle `Unary`
simplify by not returning an additional `Expr` from the `IdentIter`
add cross product test against false positives
rename suspicious_chained_operators to suspicious_operation_groupings within files
For the record, the exact commands run were:
find . -type f -name "*.md" -exec sed -i 's/suspicious_chained_operators/suspicious_operation_groupings/g' {} +
find . -type f -name "*.rs" -exec sed -i 's/suspicious_chained_operators/suspicious_operation_groupings/g' {} +
find . -type f -name "*.rs" -exec sed -i 's/SUSPICIOUS_CHAINED_OPERATORS/SUSPICIOUS_OPERATION_GROUPINGS/g' {} +
find . -type f -name "*.rs" -exec sed -i 's/SuspiciousChainedOperators/SuspiciousOperationGroupings/g' {} +
Also:
rename file to match module name
rename test file to match lint name
start implementing `IdentDifference` creation
add `IdentIter` utility
use `ident_iter::IdentIter`
fix bug in `suggestion_with_swapped_ident`
add `inside_if_statements` test
implement `Add` `todo`s
register `SuspiciousOperationGroupings` lint pass
fill in `chained_binops`, and fill in a stopgap version of `ident_difference_expr`, but then notice that the lint does not seem to ever be run in the tests
run `cargo dev update_lints` and not that the `suspicious_operation_groupings` lint still does not seem to be run
fix base index incrementing bug
fix paired_identifiers bug, and remove ident from `Single`
change help prefix and note our first successful lint messages!
add odd_number_of_pairs test
get the `non_boolean_operators` test passing, with two copies of the error message
extract `is_useless_with_eq_exprs` so we can know when `eq_op` will already handle something
add `not_caught_by_eq_op` tests since `s1.b * s1.b` was (reasonably) not caught by `eq_op`
cover the case where the change should be made on either side of the expression with `not_caught_by_eq_op` tests
produce the expected suggestion on the `not_caught_by_eq_op_middle_change_left` test
confirm that the previous tests still pass and update references
fix early continue bug and get `not_caught_by_eq_op_middle_change_right` passing
note that `not_caught_by_eq_op_start` already passes
fix bugs based on misunderstanding of what `Iterator::skip` does, and note that `not_caught_by_eq_op_end` now passes
add several parens tests and make some of them pass
handle parens inside `chained_binops_helper` and note that this makes several tests pass
get `inside_larger_boolean_expression_with_unsorted_ops` test passing by extracting out `check_same_op_binops` function
also run `cargo dev fmt`
note that `inside_function_call` already passes
add another `if_statement` test
remove the matching op requirement, making `inside_larger_boolean_expression_with_unsorted_ops` pass
prevent non-change suggestions from being emitted
get the `Nested` tests passing, and remove apparently false note about eq_op
add a test to justify comment in `ident_difference_expr_with_base_location` but find that the failure mode seems different than expected
complete `todo` making `do_not_give_bad_suggestions_for_this_unusual_expr` pass and add some more tests that already pass
add test to `eq_op`
note that `inside_fn_with_similar_expression` already passes
fix `inside_an_if_statement` and note that it already passes
attempt to implement if statement extraction and notice that we don't seem to handle unary ops correctly
add `maximum_unary_minus_right_tree` test and make it pass
add two tests and note one of them passes
filter out unary operations in several places, and find that the issue seems to be that we don't currently recognize the error in `multiple_comparison_types_and_unary_minus` even so.
remove filtering that was causing bad suggestions
remove tests that were deemed too much for now
run `cargo dev fmt`
correct eq_op post-merge
fill out the description and delete debugging code
run `cargo dev update_lints`
update eq_op references
add parens to work around rustfmt issue #3666 and run rustfmt
https://github.com/rust-lang/rustfmt/issues/3666#issuecomment-714612257
update references after formatting
fix dogfood issues
fix multi-cursor edit
fix missed dogfood error
fix more dogfood pedantic issues, including function length
even more nesting
insert hidden definition of Vec3 so docs compile
add spaces to second struct def
reword test description comment
Co-authored-by: llogiq <bogusandre@gmail.com>
add local `use BinOpKind::*;`
Apply suggestions from code review
Co-authored-by: llogiq <bogusandre@gmail.com>
switch `SUSPICIOUS_OPERATION_GROUPINGS` to a style lint
run `cargo dev update_lints`
put both usages of `op_types` in the same closure to satisfy `borrowck`
fix compile error
Check when `from_utf8` is called from sliced byte array from string
---
*Please keep the line below*
changelog: Fix#5487: Add linter to check when `from_utf8` is called from sliced byte array from string.
Add lint for 'field_reassign_with_default` #568
changelog: Add lint for field_reassign_with_default that checks if mutable object + field modification is used to edit a binding initialized with Default::default() instead of struct constructor.
Fixes#568
Notes:
- Checks for reassignment of one or more fields of a binding initialized with Default::default().
- Implemented using EarlyLintPass, might be future proofed better with LateLintPass.
- Does not trigger if Default::default() is used via another type implementing Default.
- This is a re-open of [PR#4761](https://github.com/rust-lang/rust-clippy/pull/4761), but I couldn't figure out how to re-open that one so here's a new one with the requested changes :S
Add lint 'ref_option_ref' #1377
This lint checks for usage of `&Option<&T>` which can be simplified as `Option<&T>` as suggested in #1377.
This WIP PR is here to get feedback on the lint as there's more cases to be handled:
* statics/consts,
* associated types,
* type alias,
* function/method parameter/return,
* ADT definitions (struct/tuple struct fields, enum variants)
changelog: Add 'ref_option_ref' lint
Add lint: from_iter_instead_of_collect
Fixes#5679
This implements lint for `::from_iter()` from #5679 not the general issue (`std::ops::Add::add`, etc.).
This lint checks if expression is function call with `from_iter` name and if it's implementation of the `std::iter::FromIterator` trait.
changelog: Introduce from_iter_instead_of_collect lint
- Implement `field_reassign_with_default` as a `LateLintPass`
- Avoid triggering `default_trait_access` on a span already linted by
`field_reassigned_with_default`
- Merge `default_trait_access` and `field_reassign_with_default` into
`Default`
- Co-authored-by: Eduardo Broto <ebroto@tutanota.com>
- Fixes#568
Add lint for comparing to empty slices instead of using .is_empty()
Hey first time making a clippy lint
I added the implementation of the lint the `len_zero` since it shared a lot of the code, I would otherwise have to rewrite. Just tell me if the lint should use it's own file instead
changelog: Add lint for comparing to empty slices
Fixes#6217
New lint: manual-range-contains
This fixes#1110, at least for the contains-suggesting part.
- \[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: new lint: manual-range-contains
Add lint for `&mut Mutex::lock`
Fixes#1765
changelog: Add lint [`mut_mutex_lock`] for `&mut Mutex::lock` and suggests using `&mut Mutex::get_mut` instead.
Add new lint for undropped ManuallyDrop values
Adds a new lint for the following code:
```rust
struct S;
impl Drop for S {
fn drop(&mut self) {
println!("drip drop");
}
}
fn main() {
// This will not drop the `S`!!!
drop(std::mem::ManuallyDrop::new(S));
unsafe {
// This will.
std::mem::ManuallyDrop::drop(&mut std::mem::ManuallyDrop::new(S));
}
}
```
The inner value of a `ManuallyDrop` will not be dropped unless the proper, unsafe drop function is called on it. This lint makes sure that a user does not accidently use the wrong function and forget to drop a `ManuallyDrop` value.
Fixes#5581.
---
*Please keep the line below*
changelog: none
Add lint for holding RefCell Ref across an await
Fixes#6008
This introduces the lint await_holding_refcell_ref. For async functions, we iterate
over all types in generator_interior_types and look for `core::cell::Ref` or `core::cell::RefMut`. If we find one then we emit a lint.
Heavily cribs from: https://github.com/rust-lang/rust-clippy/pull/5439
changelog: introduce the await_holding_refcell_ref lint
Refactor trivially_copy_pass_by_ref and the new lint into pass_by_ref_or_value module
Update stderr of conf_unknown_key test
Rename lint to large_types_passed_by_value
Increase `pass_by_value_size_limit` default value to 256
Improve rules for `large_types_passed_by_value`
Improve tests for `large_types_passed_by_value`
Improve documentation for `large_types_passed_by_value`
Make minor corrections to pass_by_ref_or_value.rs suggested by clippy itself
Fix `large_types_passed_by_value` example and improve docs
pass_by_ref_or_value: Tweak check for mut annotation in params
large_types_passed_by_value: add tests for pub trait, trait impl and inline attributes
New lint: Recommend using `ptr::eq` when possible
This is based almost entirely on the code available in the previous PR #4596. I merely updated the code to make it compile.
Fixes#3661.
- [ ] I'm not sure about the lint name, but it was the one used in the original PR.
- [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: none
Add `rc_buffer` lint for checking Rc<String> and friends
Fixes#2623
This is a bit different from the original PR attempting to implement this type of lint. Rather than linting against converting into the unwanted types, this PR lints against declaring the unwanted type in a struct or function definition.
I'm reasonably happy with what I have here, although I used the fully qualified type names for the Path and OsString suggestions, and I'm not sure if I should have just used the short versions instead, even if they might not have been declared via use.
Also, I don't know if "buffer type" is the best way to put it or not. Alternatively I could call it a "growable type" or "growable buffer type", but I was thinking of PathBuf when I started making the lint.
changelog: Add `rc_buffer` lint
Add map_err_ignore lint
In a large code base a lot of times errors are ignored by using something like:
```rust
foo.map_err(|_| Some::Enum)?;
```
This drops the original error in favor of a enum that will not have the original error's context. This lint helps catch throwing away the original error in favor of an enum without its context.
---
*Please keep the line below*
changelog: Added map_err_ignore lint
Add a new lint, `manual-strip`, that suggests using the `str::strip_prefix`
and `str::strip_suffix` methods introduced in Rust 1.45 when the same
functionality is performed 'manually'.
Closes#5734
Add lint panic in result
### Change
Adding a new "restriction" lint that will emit a warning when using "panic", "unimplemented" or "unreachable" in a function of type option/result.
### Motivation
Some codebases must avoid crashes at all costs, and hence functions of type option/result must return an error instead of crashing.
### Test plan
Running:
TESTNAME=panic_in_result cargo uitest ---
changelog: none
This catches bugs of the form
tokio::spawn(async move {
let f = some_async_thing();
f // Oh no I forgot to await f so that work will never complete.
});
Warn about assignments where left-hand side place expression is the same
as right-hand side value expression. For example, warn about assignment in:
```rust
pub struct Event {
id: usize,
x: i32,
y: i32,
}
pub fn copy_position(a: &mut Event, b: &Event) {
a.x = b.x;
a.y = a.y;
}
```
This lint catches cases where the last statement of a closure expecting
an instance of Ord has a trailing semi-colon. It compiles since the
closure ends up return () which also implements Ord but causes
unexpected results in cases such as sort_by_key.
Fixes#5080
reprise: rebase, update and address all concerns
New lint: iter_next_slice
Hello, this is a work-in-progress PR for issue: https://github.com/rust-lang/rust-clippy/issues/5572
I have implemented lint to replace `iter().next()` for `slice[index..]` and `array` with `get(index)` and `get(0)` respectively. However since I made a lot of changes, I would like to request some feedback before continuing so that I could fix mistakes.
Thank you!
---
changelog: implement `iter_next_slice` lint and test, and modify `needless_continues`, `for_loop_over_options_result` UI tests since they have `iter().next()`
New lint: `match_wildcard_for_single_variants`
changelog: Added a new lint match_wildcard_for_single_variants to warn on enum matches where a wildcard is used to match a single variant
Closes#5556
Rename lint `identity_conversion` to `useless_conversion`
Lint name `identity_conversion` was misleading, so this PR renames it to `useless_conversion`.
As decision has not really came up in the issue comments, this PR will probably need discussion.
fixes#3106
changelog: Rename lint `identity_conversion` to `useless_conversion`
New lint `match_vec_item`
Added new lint to warn a match on index item which can panic. It's always better to use `get(..)` instead.
Closes#5500
changelog: New lint `match_on_vec_items`
Fixes#4226
This introduces the lint await_holding_lock. For async functions, we iterate
over all types in generator_interior_types and look for types named MutexGuard,
RwLockReadGuard, or RwLockWriteGuard. If we find one then we emit a lint.
If let else mutex
changelog: Adds lint to catch incorrect use of `Mutex::lock` in `if let` expressions with lock calls in any of the blocks.
closes: #5219
Add lint on large non scalar const
This PR adds the new lint `non_scalar_const` that aims to warn against `const` declaration of large arrays. For performance, because of inlining, large arrays should be preferably declared as `static`.
Note: i made this one to warn on all const arrays, whether they are in a body function or not. I don't know if this is really necessary, i could just reduce this lint to variables out of function scope.
Fixes: #400
changelog: add new lint for large non-scalar types declared as const
Result<T, E> has an `ok()` method that adapts a Result<T,E> into an Option<T>.
It's possible to get around this adapter by writing Result<T,E>.map_or(None, Some).
This lint is implemented as a new variant of the existing
[`option_map_none` lint](https://github.com/rust-lang/rust-clippy/pull/2128)
Lint for `pub(crate)` items that are not crate visible due to the visibility of the module that contains them
changelog: Add `redundant_pub_crate` lint
Closes#5274.
Add lint to detect floating point operations that can be computed more
accurately at the cost of performance. `cbrt`, `ln_1p` and `exp_m1`
library functions call their equivalent cmath implementations which is
slower but more accurate so moving checks for these under this new lint.
