fix: async expression indentation (#3789)

Author: calebcartwright

src/utils.rs

@@ -452,8 +452,10 @@ pub(crate) fn is_block_expr(context: &RewriteContext<'_>, expr: &ast::Expr, repr
         | ast::ExprKind::While(..)
         | ast::ExprKind::If(..)
         | ast::ExprKind::Block(..)
+        | ast::ExprKind::Async(..)
         | ast::ExprKind::Loop(..)
         | ast::ExprKind::ForLoop(..)
+        | ast::ExprKind::TryBlock(..)
         | ast::ExprKind::Match(..) => repr.contains('\n'),
         ast::ExprKind::Paren(ref expr)
         | ast::ExprKind::Binary(_, _, ref expr)
@@ -466,7 +468,25 @@ pub(crate) fn is_block_expr(context: &RewriteContext<'_>, expr: &ast::Expr, repr
         ast::ExprKind::Lit(_) => {
             repr.contains('\n') && trimmed_last_line_width(repr) <= context.config.tab_spaces()
         }
-        _ => false,
+        ast::ExprKind::AddrOf(..)
+        | ast::ExprKind::Assign(..)
+        | ast::ExprKind::AssignOp(..)
+        | ast::ExprKind::Await(..)
+        | ast::ExprKind::Box(..)
+        | ast::ExprKind::Break(..)
+        | ast::ExprKind::Cast(..)
+        | ast::ExprKind::Continue(..)
+        | ast::ExprKind::Err
+        | ast::ExprKind::Field(..)
+        | ast::ExprKind::InlineAsm(..)
+        | ast::ExprKind::Let(..)
+        | ast::ExprKind::Path(..)
+        | ast::ExprKind::Range(..)
+        | ast::ExprKind::Repeat(..)
+        | ast::ExprKind::Ret(..)
+        | ast::ExprKind::Tup(..)
+        | ast::ExprKind::Type(..)
+        | ast::ExprKind::Yield(None) => false,
     }
 }
 

tests/source/expr.rs

@@ -545,3 +545,21 @@ fn overflow_with_attr() {
     foobar(x, y, #[cfg(feature = "zero")]
            {});
 }
+
+
+// https://github.com/rust-lang/rustfmt/issues/3765
+fn foo() {
+    async {
+        // Do
+        // some
+        // work
+    }
+    .await;
+
+    async {
+        // Do
+        // some
+        // work
+    }
+        .await;
+}

tests/target/expr.rs

@@ -638,3 +638,20 @@ fn overflow_with_attr() {
         {},
     );
 }
+
+// https://github.com/rust-lang/rustfmt/issues/3765
+fn foo() {
+    async {
+        // Do
+        // some
+        // work
+    }
+    .await;
+
+    async {
+        // Do
+        // some
+        // work
+    }
+    .await;
+}