Fixes #2586

compiler/fmt/src/annotation.rs

@@ -293,6 +293,9 @@ impl<'a> Formattable for TypeAnnotation<'a> {
 
             SpaceBefore(ann, spaces) => {
                 buf.newline();
+
+                buf.indent(indent);
+
                 fmt_comments_only(buf, spaces.iter(), NewlineAt::Bottom, indent);
                 ann.format_with_options(buf, parens, Newlines::No, indent)
             }

compiler/fmt/tests/test_fmt.rs

@@ -2984,6 +2984,18 @@ mod test_fmt {
         ));
     }
 
+    #[test]
+    fn multiline_higher_order_function() {
+        expr_formats_same(indoc!(
+            r#"
+            foo :
+                (Str -> Bool) -> Bool
+
+            42
+            "#
+        ));
+    }
+
     #[test]
     /// Test that everything under examples/ is formatted correctly
     /// If this test fails on your diff, it probably means you need to re-format the examples.