unwrap_used: Fix error message for unwrap_err when expect_used is allowed

clippy_lints/src/methods/unwrap_used.rs

@@ -25,7 +25,7 @@ pub(super) fn check(
         None
     };
 
-    let method = if is_err { "unwrap_err" } else { "unwrap" };
+    let method_suffix = if is_err { "_err" } else { "" };
 
     if allow_unwrap_in_tests && is_in_test_function(cx.tcx, expr.hir_id) {
         return;
@@ -35,7 +35,7 @@ pub(super) fn check(
         let help = if is_lint_allowed(cx, EXPECT_USED, expr.hir_id) {
             format!(
                 "if you don't want to handle the `{none_value}` case gracefully, consider \
-                using `expect()` to provide a better panic message"
+                using `expect{method_suffix}()` to provide a better panic message"
             )
         } else {
             format!("if this value is {none_prefix}`{none_value}`, it will panic")
@@ -45,7 +45,7 @@ pub(super) fn check(
             cx,
             lint,
             expr.span,
-            &format!("used `{method}()` on `{kind}` value"),
+            &format!("used `unwrap{method_suffix}()` on `{kind}` value"),
             None,
             &help,
         );

tests/ui/expect.rs

@@ -6,8 +6,9 @@ fn expect_option() {
 }
 
 fn expect_result() {
-    let res: Result<u8, ()> = Ok(0);
+    let res: Result<u8, u8> = Ok(0);
     let _ = res.expect("");
+    let _ = res.expect_err("");
 }
 
 fn main() {

tests/ui/expect.stderr

@@ -15,5 +15,13 @@ LL |     let _ = res.expect("");
    |
    = help: if this value is an `Err`, it will panic
 
-error: aborting due to 2 previous errors
+error: used `expect_err()` on `a Result` value
+  --> $DIR/expect.rs:11:13
+   |
+LL |     let _ = res.expect_err("");
+   |             ^^^^^^^^^^^^^^^^^^
+   |
+   = help: if this value is an `Ok`, it will panic
+
+error: aborting due to 3 previous errors
 

tests/ui/unwrap.rs

@@ -6,8 +6,9 @@ fn unwrap_option() {
 }
 
 fn unwrap_result() {
-    let res: Result<u8, ()> = Ok(0);
+    let res: Result<u8, u8> = Ok(0);
     let _ = res.unwrap();
+    let _ = res.unwrap_err();
 }
 
 fn main() {

tests/ui/unwrap.stderr

@@ -15,5 +15,13 @@ LL |     let _ = res.unwrap();
    |
    = help: if you don't want to handle the `Err` case gracefully, consider using `expect()` to provide a better panic message
 
-error: aborting due to 2 previous errors
+error: used `unwrap_err()` on `a Result` value
+  --> $DIR/unwrap.rs:11:13
+   |
+LL |     let _ = res.unwrap_err();
+   |             ^^^^^^^^^^^^^^^^
+   |
+   = help: if you don't want to handle the `Ok` case gracefully, consider using `expect_err()` to provide a better panic message
+
+error: aborting due to 3 previous errors