unnecessary_wraps: do not include the whole body in the lint span

Using the function declaration, by stripping the body, is enough to
convey the lint message.

Author: samueltardieu

clippy_lints/src/unnecessary_wraps.rs

@@ -1,6 +1,6 @@
 use clippy_config::Conf;
 use clippy_utils::diagnostics::span_lint_and_then;
-use clippy_utils::source::snippet;
+use clippy_utils::source::{HasSession, snippet, trim_span};
 use clippy_utils::visitors::find_all_ret_expressions;
 use clippy_utils::{contains_return, is_res_lang_ctor, path_res, return_ty};
 use rustc_errors::Applicability;
@@ -159,15 +159,22 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryWraps {
                 )
             };
 
-            span_lint_and_then(cx, UNNECESSARY_WRAPS, span, lint_msg, |diag| {
-                diag.span_suggestion(
-                    fn_decl.output.span(),
-                    return_type_sugg_msg,
-                    return_type_sugg,
-                    Applicability::MaybeIncorrect,
-                );
-                diag.multipart_suggestion(body_sugg_msg, suggs, Applicability::MaybeIncorrect);
-            });
+            span_lint_and_then(
+                cx,
+                UNNECESSARY_WRAPS,
+                // Do not include the whole body in the lint span
+                trim_span(cx.sess().source_map(), span.until(body.value.span)),
+                lint_msg,
+                |diag| {
+                    diag.span_suggestion(
+                        fn_decl.output.span(),
+                        return_type_sugg_msg,
+                        return_type_sugg,
+                        Applicability::MaybeIncorrect,
+                    );
+                    diag.multipart_suggestion(body_sugg_msg, suggs, Applicability::MaybeIncorrect);
+                },
+            );
         }
     }
 }

tests/ui/unnecessary_wraps.stderr

@@ -1,13 +1,8 @@
 error: this function's return value is unnecessarily wrapped by `Option`
   --> tests/ui/unnecessary_wraps.rs:9:1
    |
-LL | / fn func1(a: bool, b: bool) -> Option<i32> {
-LL | |
-LL | |
-LL | |     if a && b {
-...  |
-LL | | }
-   | |_^
+LL | fn func1(a: bool, b: bool) -> Option<i32> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `-D clippy::unnecessary-wraps` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::unnecessary_wraps)]`
@@ -30,14 +25,8 @@ LL ~         return 1337;
 error: this function's return value is unnecessarily wrapped by `Option`
   --> tests/ui/unnecessary_wraps.rs:24:1
    |
-LL | / fn func2(a: bool, b: bool) -> Option<i32> {
-LL | |
-LL | |
-LL | |     if a && b {
-...  |
-LL | |     if a { Some(20) } else { Some(30) }
-LL | | }
-   | |_^
+LL | fn func2(a: bool, b: bool) -> Option<i32> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: remove `Option` from the return type...
    |
@@ -54,12 +43,8 @@ LL ~     if a { 20 } else { 30 }
 error: this function's return value is unnecessarily wrapped by `Option`
   --> tests/ui/unnecessary_wraps.rs:44:1
    |
-LL | / fn func5() -> Option<i32> {
-LL | |
-LL | |
-LL | |     Some(1)
-LL | | }
-   | |_^
+LL | fn func5() -> Option<i32> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: remove `Option` from the return type...
    |
@@ -75,12 +60,8 @@ LL +     1
 error: this function's return value is unnecessarily wrapped by `Result`
   --> tests/ui/unnecessary_wraps.rs:56:1
    |
-LL | / fn func7() -> Result<i32, ()> {
-LL | |
-LL | |
-LL | |     Ok(1)
-LL | | }
-   | |_^
+LL | fn func7() -> Result<i32, ()> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: remove `Result` from the return type...
    |
@@ -96,12 +77,8 @@ LL +     1
 error: this function's return value is unnecessarily wrapped by `Option`
   --> tests/ui/unnecessary_wraps.rs:86:5
    |
-LL | /     fn func12() -> Option<i32> {
-LL | |
-LL | |
-LL | |         Some(1)
-LL | |     }
-   | |_____^
+LL |     fn func12() -> Option<i32> {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: remove `Option` from the return type...
    |
@@ -117,13 +94,8 @@ LL +         1
 error: this function's return value is unnecessary
   --> tests/ui/unnecessary_wraps.rs:115:1
    |
-LL | / fn issue_6640_1(a: bool, b: bool) -> Option<()> {
-LL | |
-LL | |
-LL | |     if a && b {
-...  |
-LL | | }
-   | |_^
+LL | fn issue_6640_1(a: bool, b: bool) -> Option<()> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: remove the return type...
    |
@@ -144,13 +116,8 @@ LL ~         return ;
 error: this function's return value is unnecessary
   --> tests/ui/unnecessary_wraps.rs:130:1
    |
-LL | / fn issue_6640_2(a: bool, b: bool) -> Result<(), i32> {
-LL | |
-LL | |
-LL | |     if a && b {
-...  |
-LL | | }
-   | |_^
+LL | fn issue_6640_2(a: bool, b: bool) -> Result<(), i32> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 help: remove the return type...
    |