add followup lint directions to test

Author: kartva

tests/ui/iter_kv_map.fixed

@@ -25,6 +25,9 @@ fn main() {
     // Don't lint
     map.iter().filter(|(_, val)| *val % 2 == 0).map(|(key, _)| key).count();
 
+    // Linting the following could be an improvement to the lint
+    // map.iter().filter_map(|(_, val)| (val % 2 == 0).then(val * 17)).count();
+
     // Lint
     map.keys().map(|key| key * 9).count();
     map.values().map(|value| value * 17).count();

tests/ui/iter_kv_map.rs

@@ -25,6 +25,9 @@ fn main() {
     // Don't lint
     map.iter().filter(|(_, val)| *val % 2 == 0).map(|(key, _)| key).count();
 
+    // Linting the following could be an improvement to the lint
+    // map.iter().filter_map(|(_, val)| (val % 2 == 0).then(val * 17)).count();
+
     // Lint
     map.iter().map(|(key, _value)| key * 9).count();
     map.iter().map(|(_key, value)| value * 17).count();

tests/ui/iter_kv_map.stderr

@@ -49,73 +49,73 @@ LL |     map.iter().map(|(key, _)| key).filter(|x| *x % 2 == 0).count();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `map.keys()`
 
 error: you seem to want to iterate on a map's keys
-  --> $DIR/iter_kv_map.rs:29:5
+  --> $DIR/iter_kv_map.rs:32:5
    |
 LL |     map.iter().map(|(key, _value)| key * 9).count();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the corresponding method: `map.keys().map(|key| key * 9)`
 
 error: you seem to want to iterate on a map's values
-  --> $DIR/iter_kv_map.rs:30:5
+  --> $DIR/iter_kv_map.rs:33:5
    |
 LL |     map.iter().map(|(_key, value)| value * 17).count();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the corresponding method: `map.values().map(|value| value * 17)`
 
 error: iterating on a map's keys
-  --> $DIR/iter_kv_map.rs:34:13
+  --> $DIR/iter_kv_map.rs:37:13
    |
 LL |     let _ = map.iter().map(|(key, _)| key).collect::<Vec<_>>();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `map.keys()`
 
 error: iterating on a map's values
-  --> $DIR/iter_kv_map.rs:35:13
+  --> $DIR/iter_kv_map.rs:38:13
    |
 LL |     let _ = map.iter().map(|(_, value)| value).collect::<Vec<_>>();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `map.values()`
 
 error: you seem to want to iterate on a map's values
-  --> $DIR/iter_kv_map.rs:36:13
+  --> $DIR/iter_kv_map.rs:39:13
    |
 LL |     let _ = map.iter().map(|(_, v)| v + 2).collect::<Vec<_>>();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the corresponding method: `map.values().map(|v| v + 2)`
 
 error: iterating on a map's keys
-  --> $DIR/iter_kv_map.rs:38:13
+  --> $DIR/iter_kv_map.rs:41:13
    |
 LL |     let _ = map.clone().into_iter().map(|(key, _)| key).collect::<Vec<_>>();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `map.clone().into_keys()`
 
 error: you seem to want to iterate on a map's keys
-  --> $DIR/iter_kv_map.rs:39:13
+  --> $DIR/iter_kv_map.rs:42:13
    |
 LL |     let _ = map.clone().into_iter().map(|(key, _)| key + 2).collect::<Vec<_>>();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the corresponding method: `map.clone().into_keys().map(|key| key + 2)`
 
 error: iterating on a map's values
-  --> $DIR/iter_kv_map.rs:41:13
+  --> $DIR/iter_kv_map.rs:44:13
    |
 LL |     let _ = map.clone().into_iter().map(|(_, val)| val).collect::<Vec<_>>();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `map.clone().into_values()`
 
 error: you seem to want to iterate on a map's values
-  --> $DIR/iter_kv_map.rs:42:13
+  --> $DIR/iter_kv_map.rs:45:13
    |
 LL |     let _ = map.clone().into_iter().map(|(_, val)| val + 2).collect::<Vec<_>>();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the corresponding method: `map.clone().into_values().map(|val| val + 2)`
 
 error: iterating on a map's keys
-  --> $DIR/iter_kv_map.rs:45:5
+  --> $DIR/iter_kv_map.rs:48:5
    |
 LL |     map.iter().map(|(key, _)| key).filter(|x| *x % 2 == 0).count();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `map.keys()`
 
 error: you seem to want to iterate on a map's keys
-  --> $DIR/iter_kv_map.rs:51:5
+  --> $DIR/iter_kv_map.rs:54:5
    |
 LL |     map.iter().map(|(key, _value)| key * 9).count();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the corresponding method: `map.keys().map(|key| key * 9)`
 
 error: you seem to want to iterate on a map's values
-  --> $DIR/iter_kv_map.rs:52:5
+  --> $DIR/iter_kv_map.rs:55:5
    |
 LL |     map.iter().map(|(_key, value)| value * 17).count();
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use the corresponding method: `map.values().map(|value| value * 17)`