make it work for locals as well

oopos

book/src/lint_configuration.md

@@ -643,3 +643,23 @@ The byte size a `T` in `Box<T>` can have, below which it triggers the `clippy::u
 * [`unnecessary_box_returns`](https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_box_returns)
 
 
+## `allowed-idents-below-min-chars`
+Allowed names below the minimum allowed characters.
+
+**Default Value:** `{"j", "z", "i", "y", "n", "x", "w"}` (`rustc_data_structures::fx::FxHashSet<String>`)
+
+---
+**Affected lints:**
+* [`min_ident_chars`](https://rust-lang.github.io/rust-clippy/master/index.html#min_ident_chars)
+
+
+## `min-ident-chars-threshold`
+Minimum chars an ident can have, anything below or equal to this will be linted.
+
+**Default Value:** `1` (`u64`)
+
+---
+**Affected lints:**
+* [`min_ident_chars`](https://rust-lang.github.io/rust-clippy/master/index.html#min_ident_chars)
+
+

clippy_lints/src/min_ident_chars.rs

@@ -3,7 +3,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_hir::{
     def::{DefKind, Res},
     intravisit::{walk_item, Visitor},
-    GenericParamKind, HirId, Item, ItemKind, ItemLocalId, Node,
+    GenericParamKind, HirId, Item, ItemKind, ItemLocalId, Node, Pat, PatKind,
 };
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
@@ -55,15 +55,38 @@ impl LateLintPass<'_> for MinIdentChars {
 
         walk_item(&mut IdentVisitor { conf: self, cx }, item);
     }
+
+    // This is necessary as bindings are not visited in `visit_id`. :/
+    #[expect(clippy::cast_possible_truncation)]
+    fn check_pat(&mut self, cx: &LateContext<'_>, pat: &Pat<'_>) {
+        if let PatKind::Binding(_, _, ident, ..) = pat.kind
+            && let str = ident.as_str()
+            && !in_external_macro(cx.sess(), ident.span)
+            && str.len() <= self.min_ident_chars_threshold as usize
+            && !str.is_empty()
+            && self.allowed_idents_below_min_chars.get(&str.to_owned()).is_none()
+        {
+            let help = if self.min_ident_chars_threshold == 1 {
+                Cow::Borrowed("this ident consists of a single char")
+            } else {
+                Cow::Owned(format!(
+                    "this ident is too short ({} <= {})",
+                    str.len(),
+                    self.min_ident_chars_threshold,
+                ))
+            };
+            span_lint(cx, MIN_IDENT_CHARS, ident.span, &help);
+        }
+    }
 }
 
 struct IdentVisitor<'cx, 'tcx> {
     conf: &'cx MinIdentChars,
     cx: &'cx LateContext<'tcx>,
 }
 
-#[expect(clippy::cast_possible_truncation)]
 impl Visitor<'_> for IdentVisitor<'_, '_> {
+    #[expect(clippy::cast_possible_truncation)]
     fn visit_id(&mut self, hir_id: HirId) {
         let Self { conf, cx } = *self;
         // Reimplementation of `find`, as it uses indexing, which can (and will in async functions) panic.
@@ -122,9 +145,9 @@ impl Visitor<'_> for IdentVisitor<'_, '_> {
                 Cow::Borrowed("this ident consists of a single char")
             } else {
                 Cow::Owned(format!(
-                    "this ident is too short ({} <= {}) ",
+                    "this ident is too short ({} <= {})",
                     str.len(),
-                    conf.min_ident_chars_threshold
+                    conf.min_ident_chars_threshold,
                 ))
             };
             span_lint(cx, MIN_IDENT_CHARS, ident.span, &help);

clippy_lints/src/utils/conf.rs

@@ -34,7 +34,7 @@ const DEFAULT_DOC_VALID_IDENTS: &[&str] = &[
     "CamelCase",
 ];
 const DEFAULT_DISALLOWED_NAMES: &[&str] = &["foo", "baz", "quux"];
-const DEFAULT_ALLOWED_IDENTS_BELOW_MIN_CHARS: &[&str] = &["i", "j", "x", "y", "z", "n"];
+const DEFAULT_ALLOWED_IDENTS_BELOW_MIN_CHARS: &[&str] = &["i", "j", "x", "y", "z", "w", "n"];
 
 /// Holds information used by `MISSING_ENFORCED_IMPORT_RENAMES` lint.
 #[derive(Clone, Debug, Deserialize)]

tests/ui-toml/min_ident_chars/min_ident_chars.rs

@@ -14,4 +14,6 @@ fn main() {
     let wha = 1;
     let vvv = 1;
     let uuu = 1;
+    let (mut a, mut b) = (1, 2);
+    for i in 0..1000 {}
 }

tests/ui-toml/min_ident_chars/min_ident_chars.stderr

@@ -1,16 +1,46 @@
-error: this ident is too short (3 <= 3) 
+error: this ident is too short (3 <= 3)
   --> $DIR/min_ident_chars.rs:6:19
    |
 LL | use extern_types::Aaa;
    |                   ^^^
    |
    = note: `-D clippy::min-ident-chars` implied by `-D warnings`
 
-error: this ident is too short (3 <= 3) 
+error: this ident is too short (3 <= 3)
   --> $DIR/min_ident_chars.rs:10:5
    |
 LL |     aaa: Aaa,
    |     ^^^
 
-error: aborting due to 2 previous errors
+error: this ident is too short (3 <= 3)
+  --> $DIR/min_ident_chars.rs:15:9
+   |
+LL |     let vvv = 1;
+   |         ^^^
+
+error: this ident is too short (3 <= 3)
+  --> $DIR/min_ident_chars.rs:16:9
+   |
+LL |     let uuu = 1;
+   |         ^^^
+
+error: this ident is too short (1 <= 3)
+  --> $DIR/min_ident_chars.rs:17:14
+   |
+LL |     let (mut a, mut b) = (1, 2);
+   |              ^
+
+error: this ident is too short (1 <= 3)
+  --> $DIR/min_ident_chars.rs:17:21
+   |
+LL |     let (mut a, mut b) = (1, 2);
+   |                     ^
+
+error: this ident is too short (1 <= 3)
+  --> $DIR/min_ident_chars.rs:18:9
+   |
+LL |     for i in 0..1000 {}
+   |         ^
+
+error: aborting due to 7 previous errors
 

tests/ui/min_ident_chars.rs

@@ -1,5 +1,5 @@
 //@aux-build:proc_macros.rs
-#![allow(nonstandard_style, unused)]
+#![allow(irrefutable_let_patterns, nonstandard_style, unused)]
 #![warn(clippy::min_ident_chars)]
 
 extern crate proc_macros;
@@ -15,6 +15,10 @@ struct A {
 
 struct B(u32);
 
+struct O {
+    o: u32,
+}
+
 struct i;
 
 enum C {
@@ -38,11 +42,29 @@ fn main() {
     let w = 1;
     // Ok, not this one
     // let i = 1;
-    let jz = 1;
-    let nz = 1;
-    let zx = 1;
-    let yz = 1;
-    let zz = 1;
+    let j = 1;
+    let n = 1;
+    let z = 1;
+    let y = 1;
+    let z = 1;
+    // Implicitly disallowed idents
+    let h = 1;
+    let e = 2;
+    let l = 3;
+    let l = 4;
+    let o = 6;
+    // 2 len does not lint
+    let hi = 0;
+    // Lint
+    let (h, o, w) = (1, 2, 3);
+    for (a, (r, e)) in (0..1000).enumerate().enumerate() {}
+    let you = Vec4 { x: 1, y: 2, z: 3, w: 4 };
+    while let (d, o, _i, n, g) = (true, true, false, false, true) {}
+    let today = true;
+    // Ideally this wouldn't lint, but this would (likely) require global analysis, outta scope
+    // of this lint regardless
+    let o = 1;
+    let o = O { o };
 
     for j in 0..1000 {}
 

tests/ui/min_ident_chars.stderr

@@ -31,40 +31,136 @@ LL | struct B(u32);
    |        ^
 
 error: this ident consists of a single char
-  --> $DIR/min_ident_chars.rs:20:6
+  --> $DIR/min_ident_chars.rs:18:8
+   |
+LL | struct O {
+   |        ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:19:5
+   |
+LL |     o: u32,
+   |     ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:24:6
    |
 LL | enum C {
    |      ^
 
 error: this ident consists of a single char
-  --> $DIR/min_ident_chars.rs:21:5
+  --> $DIR/min_ident_chars.rs:25:5
    |
 LL |     D,
    |     ^
 
 error: this ident consists of a single char
-  --> $DIR/min_ident_chars.rs:22:5
+  --> $DIR/min_ident_chars.rs:26:5
    |
 LL |     E,
    |     ^
 
 error: this ident consists of a single char
-  --> $DIR/min_ident_chars.rs:23:5
+  --> $DIR/min_ident_chars.rs:27:5
    |
 LL |     F,
    |     ^
 
 error: this ident consists of a single char
-  --> $DIR/min_ident_chars.rs:31:5
+  --> $DIR/min_ident_chars.rs:51:9
    |
-LL |     w: u32,
-   |     ^
+LL |     let h = 1;
+   |         ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:52:9
+   |
+LL |     let e = 2;
+   |         ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:53:9
+   |
+LL |     let l = 3;
+   |         ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:54:9
+   |
+LL |     let l = 4;
+   |         ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:55:9
+   |
+LL |     let o = 6;
+   |         ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:59:10
+   |
+LL |     let (h, o, w) = (1, 2, 3);
+   |          ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:59:13
+   |
+LL |     let (h, o, w) = (1, 2, 3);
+   |             ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:60:10
+   |
+LL |     for (a, (r, e)) in (0..1000).enumerate().enumerate() {}
+   |          ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:60:14
+   |
+LL |     for (a, (r, e)) in (0..1000).enumerate().enumerate() {}
+   |              ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:60:17
+   |
+LL |     for (a, (r, e)) in (0..1000).enumerate().enumerate() {}
+   |                 ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:62:16
+   |
+LL |     while let (d, o, _i, n, g) = (true, true, false, false, true) {}
+   |                ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:62:19
+   |
+LL |     while let (d, o, _i, n, g) = (true, true, false, false, true) {}
+   |                   ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:62:29
+   |
+LL |     while let (d, o, _i, n, g) = (true, true, false, false, true) {}
+   |                             ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:66:9
+   |
+LL |     let o = 1;
+   |         ^
+
+error: this ident consists of a single char
+  --> $DIR/min_ident_chars.rs:67:9
+   |
+LL |     let o = O { o };
+   |         ^
 
 error: this ident consists of a single char
-  --> $DIR/min_ident_chars.rs:58:4
+  --> $DIR/min_ident_chars.rs:80:4
    |
 LL | fn b() {}
    |    ^
 
-error: aborting due to 11 previous errors
+error: aborting due to 27 previous errors