span_lint_and_then

Author: lengyijun

clippy_lints/src/needless_deref.rs

@@ -1,4 +1,4 @@
-use clippy_utils::diagnostics::span_lint_and_help;
+use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::source::snippet_opt;
 use rustc_hir::{ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
@@ -63,17 +63,25 @@ impl LateLintPass<'_> for NeedlessDeref {
                     }
                 }
 
-                span_lint_and_help(
+                span_lint_and_then(
                     cx,
                     NEEDLESS_DEREF,
                     e.span,
                     "deref on an immutable borrow",
-                    None,
-                    &format!(
-                        "consider using `{}` if you would like to deref\nconsider using `{}` if you would like to reborrow",
-                        "&**".to_owned() + &snippet_opt(cx, deref_target.span).unwrap(),
-                        &snippet_opt(cx, deref_target.span).unwrap(),
-                     )
+                    |diag| {
+                        diag.help(
+                            &format!(
+                                "consider using `{}` if you would like to deref",
+                                "&**".to_owned() + &snippet_opt(cx, deref_target.span).unwrap(),
+                             )
+                        );
+                        diag.help(
+                            &format!(
+                                "consider using `{}` if you would like to reborrow",
+                                &snippet_opt(cx, deref_target.span).unwrap(),
+                             )
+                        );
+                    }
                 );
             }
         }

tests/ui/needless_deref.rs

@@ -20,7 +20,7 @@ mod should_not_lint {
         foo(&mut &*x); // should not lint
         assert_eq!(*x, 0);
 
-        foo(&mut x); // should not lint
+        foo(&mut x);
         assert_eq!(*x, 1);
     }
 }

tests/ui/needless_deref.stderr

@@ -6,7 +6,7 @@ LL |         let _b = &*a;
    |
    = note: `-D clippy::needless-deref` implied by `-D warnings`
    = help: consider using `&**a` if you would like to deref
-           consider using `a` if you would like to reborrow
+   = help: consider using `a` if you would like to reborrow
 
 error: deref on an immutable borrow
   --> $DIR/needless_deref.rs:9:23
@@ -15,7 +15,7 @@ LL |         let a: &str = &*s;
    |                       ^^^
    |
    = help: consider using `&**s` if you would like to deref
-           consider using `s` if you would like to reborrow
+   = help: consider using `s` if you would like to reborrow
 
 error: aborting due to 2 previous errors