Auto merge of #103913 - Neutron3529:patch-1, r=thomcc

[rust.git] / src / tools / rust-analyzer / crates / ide-assists / src / handlers / unnecessary_async.rs

diff --git a/src/tools/rust-analyzer/crates/ide-assists/src/handlers/unnecessary_async.rs b/src/tools/rust-analyzer/crates/ide-assists/src/handlers/unnecessary_async.rs
index d5cd2d551349d7c225be5e262ce399e2354deafb..04398832253307be610ef1da72c05d5b33fa7d20 100644 (file)
--- a/src/tools/rust-analyzer/crates/ide-assists/src/handlers/unnecessary_async.rs
+++ b/src/tools/rust-analyzer/crates/ide-assists/src/handlers/unnecessary_async.rs
@@ -44,6 +44,12 @@ pub(crate) fn unnecessary_async(acc: &mut Assists, ctx: &AssistContext<'_>) -> O
     if function.body()?.syntax().descendants().find_map(ast::AwaitExpr::cast).is_some() {
         return None;
     }
+    // Do nothing if the method is a member of trait.
+    if let Some(impl_) = function.syntax().ancestors().nth(2).and_then(ast::Impl::cast) {
+        if let Some(_) = impl_.trait_() {
+            return None;
+        }
+    }
 
     // Remove the `async` keyword plus whitespace after it, if any.
     let async_range = {
@@ -254,4 +260,18 @@ fn does_not_apply_on_function_with_a_nested_await_expr() {
     fn does_not_apply_when_not_on_prototype() {
         check_assist_not_applicable(unnecessary_async, "pub async fn f() { $0f2() }")
     }
+
+    #[test]
+    fn does_not_apply_on_async_trait_method() {
+        check_assist_not_applicable(
+            unnecessary_async,
+            r#"
+trait Trait {
+    async fn foo();
+}
+impl Trait for () {
+    $0async fn foo() {}
+}"#,
+        );
+    }
 }