[similar_names] don't raise if the first character is different

A lot of cases of the "noise" cases of `similar_names` come from two
idents with a different first letter, which is easy enough to
differentiate visually but causes this lint to be raised.

Do not raise the lint in these cases, as long as the first character
does not have a lookalike.

Link: https://github.com/rust-lang/rust-clippy/issues/10926
This commit is contained in:
Trevor Gross 2024-02-09 23:19:27 -06:00
parent 4a5e30dca7
commit 09f18f61c6
3 changed files with 32 additions and 41 deletions

View File

@ -131,6 +131,14 @@ fn check_single_char_names(&self) {
&["iter", "item"],
];
/// Characters that look visually similar
const SIMILAR_CHARS: &[(char, char)] = &[('l', 'i'), ('l', '1'), ('i', '1'), ('u', 'v')];
/// Return true if two characters are visually similar
fn chars_are_similar(a: char, b: char) -> bool {
a == b || SIMILAR_CHARS.contains(&(a, b)) || SIMILAR_CHARS.contains(&(b, a))
}
struct SimilarNamesNameVisitor<'a, 'tcx, 'b>(&'b mut SimilarNamesLocalVisitor<'a, 'tcx>);
impl<'a, 'tcx, 'b> Visitor<'tcx> for SimilarNamesNameVisitor<'a, 'tcx, 'b> {
@ -219,6 +227,16 @@ fn check_ident(&mut self, ident: Ident) {
}
let existing_str = existing_name.interned.as_str();
// The first char being different is usually enough to set identifiers apart, as long
// as the characters aren't too similar.
if !chars_are_similar(
interned_name.chars().next().expect("len >= 1"),
existing_str.chars().next().expect("len >= 1"),
) {
continue;
}
let dissimilar = match existing_name.len.cmp(&count) {
Ordering::Greater => existing_name.len - count != 1 || levenstein_not_1(interned_name, existing_str),
Ordering::Less => count - existing_name.len != 1 || levenstein_not_1(existing_str, interned_name),

View File

@ -17,13 +17,10 @@ fn main() {
let specter: i32;
let spectre: i32;
// ok; first letter is different enough
let apple: i32;
let bpple: i32;
//~^ ERROR: binding's name is too similar to existing binding
let cpple: i32;
//~^ ERROR: binding's name is too similar to existing binding
let a_bar: i32;
let b_bar: i32;

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@ -1,88 +1,64 @@
error: binding's name is too similar to existing binding
--> $DIR/similar_names.rs:22:9
|
LL | let bpple: i32;
| ^^^^^
|
note: existing binding defined here
--> $DIR/similar_names.rs:20:9
|
LL | let apple: i32;
| ^^^^^
= note: `-D clippy::similar-names` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::similar_names)]`
error: binding's name is too similar to existing binding
--> $DIR/similar_names.rs:25:9
|
LL | let cpple: i32;
| ^^^^^
|
note: existing binding defined here
--> $DIR/similar_names.rs:20:9
|
LL | let apple: i32;
| ^^^^^
error: binding's name is too similar to existing binding
--> $DIR/similar_names.rs:50:9
--> $DIR/similar_names.rs:47:9
|
LL | let bluby: i32;
| ^^^^^
|
note: existing binding defined here
--> $DIR/similar_names.rs:49:9
--> $DIR/similar_names.rs:46:9
|
LL | let blubx: i32;
| ^^^^^
= note: `-D clippy::similar-names` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::similar_names)]`
error: binding's name is too similar to existing binding
--> $DIR/similar_names.rs:55:9
--> $DIR/similar_names.rs:52:9
|
LL | let coke: i32;
| ^^^^
|
note: existing binding defined here
--> $DIR/similar_names.rs:53:9
--> $DIR/similar_names.rs:50:9
|
LL | let cake: i32;
| ^^^^
error: binding's name is too similar to existing binding
--> $DIR/similar_names.rs:74:9
--> $DIR/similar_names.rs:71:9
|
LL | let xyzeabc: i32;
| ^^^^^^^
|
note: existing binding defined here
--> $DIR/similar_names.rs:72:9
--> $DIR/similar_names.rs:69:9
|
LL | let xyz1abc: i32;
| ^^^^^^^
error: binding's name is too similar to existing binding
--> $DIR/similar_names.rs:79:9
--> $DIR/similar_names.rs:76:9
|
LL | let parsee: i32;
| ^^^^^^
|
note: existing binding defined here
--> $DIR/similar_names.rs:77:9
--> $DIR/similar_names.rs:74:9
|
LL | let parser: i32;
| ^^^^^^
error: binding's name is too similar to existing binding
--> $DIR/similar_names.rs:101:16
--> $DIR/similar_names.rs:98:16
|
LL | bpple: sprang,
| ^^^^^^
|
note: existing binding defined here
--> $DIR/similar_names.rs:100:16
--> $DIR/similar_names.rs:97:16
|
LL | apple: spring,
| ^^^^^^
error: aborting due to 7 previous errors
error: aborting due to 5 previous errors