Preserve inline comments inside sig blocks during RBS translation

Comments inside `sig do params(...) end` blocks were silently dropped
because the entire sig node byte range was replaced with the RBS string.
Collect any comments within the sig node's range and prepend them to
the output before the `#:` annotation.

Author: KaanOzkan

lib/spoom/sorbet/translate/sorbet_sigs_to_rbs_comments.rb

@@ -78,6 +78,7 @@ def visit_def_node(node)
             out = rbs_print(node.location.start_column) do |printer|
               printer.print_method_sig(rbi_node, sig)
             end
+            out = add_inline_sig_comments(node, out)
             @rewriter << Source::Replace.new(node.location.start_offset, node.location.end_offset, out)
           end
 
@@ -207,6 +208,7 @@ def visit_attr(node)
             out = rbs_print(node.location.start_column) do |printer|
               printer.print_attr_sig(rbi_node, sig)
             end
+            out = add_inline_sig_comments(node, out)
             @rewriter << Source::Replace.new(node.location.start_offset, node.location.end_offset, out)
           end
         end
@@ -379,6 +381,19 @@ def delete_extend_t_generics
           @extend_t_generics.clear
         end
 
+        #: (Prism::CallNode, String) -> String
+        def add_inline_sig_comments(sig_node, out)
+          inline_comments = @comments.select do |comment|
+            comment.location.start_offset > sig_node.location.start_offset &&
+              comment.location.end_offset <= sig_node.location.end_offset
+          end
+          return out if inline_comments.empty?
+
+          indent_str = " " * sig_node.location.start_column
+          comment_string = inline_comments.map { |c| "#{c.slice}\n#{indent_str}" }.join
+          comment_string + out
+        end
+
         # Collects the last signatures visited and clears the current list
         #: -> Array[[Prism::CallNode, RBI::Sig]]
         def collect_last_sigs

rbi/spoom.rbi

@@ -3023,6 +3023,9 @@ class Spoom::Sorbet::Translate::SorbetSigsToRBSComments < ::Spoom::Sorbet::Trans
 
   private
 
+  sig { params(sig_node: ::Prism::CallNode, out: ::String).returns(::String) }
+  def add_inline_sig_comments(sig_node, out); end
+
   sig do
     params(
       parent: T.any(::Prism::ClassNode, ::Prism::ModuleNode, ::Prism::SingletonClassNode),

test/spoom/sorbet/translate/sorbet_sigs_to_rbs_comments_test.rb

@@ -466,6 +466,59 @@ def foo(param1:, param2:); end
           RBS
         end
 
+        def test_translate_to_rbs_sig_with_inline_param_comments
+          contents = <<~RB
+            sig do
+              params(
+                # First param
+                a: Integer,
+                # Second param
+                b: String
+              ).void
+            end
+            def foo(a, b); end
+
+            sig do
+              # A comment
+              returns(Integer)
+            end
+            attr_reader :x
+          RB
+
+          assert_equal(<<~RBS, sorbet_sigs_to_rbs_comments(contents))
+            # First param
+            # Second param
+            #: (Integer a, String b) -> void
+            def foo(a, b); end
+
+            # A comment
+            #: Integer
+            attr_reader :x
+          RBS
+        end
+
+        def test_translate_to_rbs_sig_with_inline_param_comments_indented
+          contents = <<~RB
+            class Foo
+              sig do
+                params(
+                  # First param
+                  a: Integer
+                ).void
+              end
+              def foo(a); end
+            end
+          RB
+
+          assert_equal(<<~RBS, sorbet_sigs_to_rbs_comments(contents))
+            class Foo
+              # First param
+              #: (Integer a) -> void
+              def foo(a); end
+            end
+          RBS
+        end
+
         def test_translate_to_rbs_defs_within_send
           contents = <<~RB
             sig { void }