Merge pull request #21485 from A4-Tacks/move-guard-clean-block

Improve move_guard redundanted block

src/tools/rust-analyzer/crates/ide-assists/src/handlers/move_guard.rs

@@ -49,7 +49,7 @@ pub(crate) fn move_guard_to_arm_body(acc: &mut Assists, ctx: &AssistContext<'_>)
 
     let guard_condition = guard.condition()?.reset_indent();
     let arm_expr = match_arm.expr()?;
-    let then_branch = make::block_expr(None, Some(arm_expr.reset_indent().indent(1.into())));
+    let then_branch = crate::utils::wrap_block(&arm_expr);
     let if_expr = make::expr_if(guard_condition, then_branch, None).indent(arm_expr.indent_level());
 
     let target = guard.syntax().text_range();
@@ -344,6 +344,35 @@ fn main() {
         );
     }
 
+    #[test]
+    fn move_guard_to_block_arm_body_works() {
+        check_assist(
+            move_guard_to_arm_body,
+            r#"
+fn main() {
+    match 92 {
+        x $0if x > 10 => {
+            let _ = true;
+            false
+        },
+        _ => true
+    }
+}
+"#,
+            r#"
+fn main() {
+    match 92 {
+        x => if x > 10 {
+            let _ = true;
+            false
+        },
+        _ => true
+    }
+}
+"#,
+        );
+    }
+
     #[test]
     fn move_let_guard_to_arm_body_works() {
         check_assist(
@@ -395,9 +424,7 @@ fn main() {
             && true
             && true {
             {
-                {
-                    false
-                }
+                false
             }
         },
         _ => true

src/tools/rust-analyzer/crates/ide-assists/src/utils.rs

@@ -86,6 +86,17 @@ pub fn extract_trivial_expression(block_expr: &ast::BlockExpr) -> Option<ast::Ex
     None
 }
 
+pub(crate) fn wrap_block(expr: &ast::Expr) -> ast::BlockExpr {
+    if let ast::Expr::BlockExpr(block) = expr
+        && let Some(first) = block.syntax().first_token()
+        && first.kind() == T!['{']
+    {
+        block.reset_indent()
+    } else {
+        make::block_expr(None, Some(expr.reset_indent().indent(1.into())))
+    }
+}
+
 /// This is a method with a heuristics to support test methods annotated with custom test annotations, such as
 /// `#[test_case(...)]`, `#[tokio::test]` and similar.
 /// Also a regular `#[test]` annotation is supported.