Add support for methods

Author: hkmatsumoto

clippy_lints/src/unnecessary_wrap.rs

@@ -64,7 +64,11 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryWrap {
         hir_id: HirId,
     ) {
         match fn_kind {
-            FnKind::ItemFn(.., visibility, _) if visibility.node.is_pub() => return,
+            FnKind::ItemFn(.., visibility, _) | FnKind::Method(.., Some(visibility), _) => {
+                if visibility.node.is_pub() {
+                    return;
+                }
+            },
             FnKind::Closure(..) => return,
             _ => (),
         }

tests/ui/unnecessary_wrap.rs

@@ -76,6 +76,20 @@ fn func9(a: bool) -> Result<i32, ()> {
     Err(())
 }
 
+struct A;
+
+impl A {
+    // should not be linted
+    pub fn func10() -> Option<i32> {
+        Some(1)
+    }
+
+    // should be linted
+    fn func11() -> Option<i32> {
+        Some(1)
+    }
+}
+
 fn main() {
     // method calls are not linted
     func1(true, true);

tests/ui/unnecessary_wrap.stderr

@@ -85,5 +85,22 @@ help: ...and change the returning expressions
 LL |     1
    |
 
-error: aborting due to 4 previous errors
+error: this function's return value is unnecessarily wrapped by `Option`
+  --> $DIR/unnecessary_wrap.rs:88:5
+   |
+LL | /     fn func11() -> Option<i32> {
+LL | |         Some(1)
+LL | |     }
+   | |_____^
+   |
+help: remove `Option` from the return type...
+   |
+LL |     fn func11() -> i32 {
+   |                    ^^^
+help: ...and change the returning expressions
+   |
+LL |         1
+   |
+
+error: aborting due to 5 previous errors