Issue rust-lang#16110: similar_names not triggered by example

Author: alt440

clippy_lints/src/non_expressive_names.rs

@@ -442,7 +442,8 @@ fn levenstein_not_1(a_name: &str, b_name: &str) -> bool {
     debug_assert!(a_name.chars().count() < b_name.chars().count());
     let mut a_chars = a_name.chars();
     let mut b_chars = b_name.chars();
-    while let (Some(a), Some(b)) = (a_chars.next(), b_chars.next()) {
+    while let Some(a) = a_chars.next() {
+        let b = b_chars.next().unwrap();
         if a == b {
             continue;
         }
@@ -454,6 +455,7 @@ fn levenstein_not_1(a_name: &str, b_name: &str) -> bool {
         // ntuple
         return true;
     }
-    // for item in items
-    true
+    // If we matched all characters of `a` but `b` is longer,
+    // it's a single insertion only if `b` has exactly one remaining char.
+    b_chars.count() != 1
 }

tests/ui/similar_names.rs

@@ -49,6 +49,7 @@ fn main() {
 
     let cake: i32;
     let cakes: i32;
+    //~^ similar_names
     let coke: i32;
     //~^ similar_names
 
@@ -59,7 +60,9 @@ fn main() {
     let cheese: i32;
     match (42, 43) {
         (cheese1, 1) => {},
+        //~^ similar_names
         (cheese2, 2) => panic!(),
+        //~^ similar_names
         _ => println!(""),
     }
     let ipv4: i32;
@@ -93,6 +96,10 @@ fn main() {
     // 3 letter names are allowed to be similar
     let kta: i32;
     let ktv: i32;
+
+    let checked_exp: i32;
+    let checked_expr: i32;
+    //~^ similar_names
 }
 
 fn foo() {

tests/ui/similar_names.stderr

@@ -13,7 +13,19 @@ LL |     let blubx: i32;
    = help: to override `-D warnings` add `#[allow(clippy::similar_names)]`
 
 error: binding's name is too similar to existing binding
-  --> tests/ui/similar_names.rs:52:9
+  --> tests/ui/similar_names.rs:51:9
+   |
+LL |     let cakes: i32;
+   |         ^^^^^
+   |
+note: existing binding defined here
+  --> tests/ui/similar_names.rs:50:9
+   |
+LL |     let cake: i32;
+   |         ^^^^
+
+error: binding's name is too similar to existing binding
+  --> tests/ui/similar_names.rs:53:9
    |
 LL |     let coke: i32;
    |         ^^^^
@@ -25,40 +37,76 @@ LL |     let cake: i32;
    |         ^^^^
 
 error: binding's name is too similar to existing binding
-  --> tests/ui/similar_names.rs:71:9
+  --> tests/ui/similar_names.rs:62:10
+   |
+LL |         (cheese1, 1) => {},
+   |          ^^^^^^^
+   |
+note: existing binding defined here
+  --> tests/ui/similar_names.rs:60:9
+   |
+LL |     let cheese: i32;
+   |         ^^^^^^
+
+error: binding's name is too similar to existing binding
+  --> tests/ui/similar_names.rs:64:10
+   |
+LL |         (cheese2, 2) => panic!(),
+   |          ^^^^^^^
+   |
+note: existing binding defined here
+  --> tests/ui/similar_names.rs:60:9
+   |
+LL |     let cheese: i32;
+   |         ^^^^^^
+
+error: binding's name is too similar to existing binding
+  --> tests/ui/similar_names.rs:74:9
    |
 LL |     let xyzeabc: i32;
    |         ^^^^^^^
    |
 note: existing binding defined here
-  --> tests/ui/similar_names.rs:69:9
+  --> tests/ui/similar_names.rs:72:9
    |
 LL |     let xyz1abc: i32;
    |         ^^^^^^^
 
 error: binding's name is too similar to existing binding
-  --> tests/ui/similar_names.rs:76:9
+  --> tests/ui/similar_names.rs:79:9
    |
 LL |     let parsee: i32;
    |         ^^^^^^
    |
 note: existing binding defined here
-  --> tests/ui/similar_names.rs:74:9
+  --> tests/ui/similar_names.rs:77:9
    |
 LL |     let parser: i32;
    |         ^^^^^^
 
 error: binding's name is too similar to existing binding
-  --> tests/ui/similar_names.rs:102:16
+  --> tests/ui/similar_names.rs:101:9
+   |
+LL |     let checked_expr: i32;
+   |         ^^^^^^^^^^^^
+   |
+note: existing binding defined here
+  --> tests/ui/similar_names.rs:100:9
+   |
+LL |     let checked_exp: i32;
+   |         ^^^^^^^^^^^
+
+error: binding's name is too similar to existing binding
+  --> tests/ui/similar_names.rs:109:16
    |
 LL |         bpple: sprang,
    |                ^^^^^^
    |
 note: existing binding defined here
-  --> tests/ui/similar_names.rs:101:16
+  --> tests/ui/similar_names.rs:108:16
    |
 LL |         apple: spring,
    |                ^^^^^^
 
-error: aborting due to 5 previous errors
+error: aborting due to 9 previous errors