add reproducible test case for #277

Author: kzkn

spec/lib/rufo/formatter_source_specs/blocks.rb.spec

@@ -278,3 +278,13 @@ map { _1**2 }
 
 #~# EXPECTED
 map { _1 ** 2 }
+
+#~# ORIGINAL command doend braces
+a.map   &method(:foo)
+ .map   do |x| x + 1; end
+ .map { _1 * 2 }
+
+#~# EXPECTED
+a.map &method(:foo)
+ .map do |x| x + 1; end
+ .map { _1 * 2 }