Transform multiline brace blocks into do blocks

librubyfmt/src/format.rs

@@ -3072,7 +3072,20 @@ fn should_multiline_call_chain(ps: &mut dyn ConcreteParserState, method_call: &M
 }
 
 pub fn format_block(ps: &mut dyn ConcreteParserState, b: Block) {
-    match b {
+    let block = match b {
+        Block::DoBlock(..) => b,
+        Block::BraceBlock(bb) => {
+            // Transform multiline BraceBlocks into do/end blocks
+            if bb.2.len() > 1
+                || ps.will_render_as_multiline(Box::new(|ps| format_brace_block(ps, bb.clone())))
+            {
+                Block::DoBlock(bb.into_do_block())
+            } else {
+                Block::BraceBlock(bb)
+            }
+        }
+    };
+    match block {
         Block::BraceBlock(bb) => format_brace_block(ps, bb),
         Block::DoBlock(db) => format_do_block(ps, db),
     }

librubyfmt/src/ripper_tree_types.rs

@@ -1912,6 +1912,17 @@ pub struct BraceBlock(
     pub StartEnd,
 );
 
+impl BraceBlock {
+    pub fn into_do_block(self) -> DoBlock {
+        DoBlock(
+            do_block_tag,
+            self.1,
+            Box::new(BodyStmt(bodystmt_tag, self.2, None, None, None)),
+            self.3,
+        )
+    }
+}
+
 def_tag!(while_tag, "while");
 #[derive(Deserialize, Debug, Clone)]
 pub struct While(