question_mark: Lint only early returns

Author: sinkuu

clippy_lints/src/question_mark.rs

@@ -146,9 +146,28 @@ impl Pass {
             }
         }
 
-        // Check if the block has an implicit return expression
-        if let Some(ref ret_expr) = block.expr {
-            return Some(ret_expr.clone());
+        // Check for `return` without a semicolon.
+        // 
+        // ```rust
+        // let _ = if self.opt.is_none() {
+        //     /* no stmts here */
+        //     return None
+        // } else {
+        //     self.opt
+        // };
+        // ```
+        //
+        // This can be rewritten as:
+        // 
+        // ```rust
+        // let _ = self.opt?;
+        // ```
+        if_chain! {
+            if block.stmts.len() == 0;
+            if let Some(ExprKind::Ret(Some(ret_expr))) = block.expr.as_ref().map(|e| &e.node);
+            then {
+                return Some(ret_expr.clone());
+            }
         }
 
         None

tests/ui/question_mark.rs

@@ -57,6 +57,12 @@ impl SomeStruct {
             self.opt
         };
 
+        let _ = if self.opt.is_none() {
+            None
+        } else {
+            self.opt
+        };
+
         let _ = if self.opt.is_none() {
             return None;
         } else {