Fix spoom srb assertions translate to preserve trailing comments in correct order

When translating T.let with trailing comments, the RBS annotation now appears
before the comment so Sorbet can properly recognize the type:

  a = T.let(3, Integer) # comment

now translates to:

  a = 3 #: Integer # comment

instead of:

  a = 3 # comment #: Integer

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: burke

lib/spoom/sorbet/translate/sorbet_assertions_to_rbs_comments.rb

@@ -89,18 +89,26 @@ def maybe_translate_assertion(node)
           return false unless translatable_annotation?(node)
           return false unless at_end_of_line?(node)
 
+          trailing_comment, comment_end_offset = extract_trailing_comment(node)
+          # If extract_trailing_comment returns nil when there's an RBS annotation, don't translate
+          return false if trailing_comment.nil? && has_rbs_annotation?(node)
+
           value = T.must(node.arguments&.arguments&.first)
           rbs_annotation = build_rbs_annotation(node)
 
           start_offset = node.location.start_offset
-          end_offset = node.location.end_offset
+          # If there's a trailing comment, replace up to the end of the comment
+          # Otherwise, replace up to the end of the node
+          end_offset = comment_end_offset || node.location.end_offset
 
-          @rewriter << if node.name == :bind
-            Source::Replace.new(start_offset, end_offset - 1, rbs_annotation)
+          replacement = if node.name == :bind
+            "#{rbs_annotation}#{trailing_comment}"
           else
-            Source::Replace.new(start_offset, end_offset - 1, "#{dedent_value(node, value)} #{rbs_annotation}")
+            "#{dedent_value(node, value)} #{rbs_annotation}#{trailing_comment}"
           end
 
+          @rewriter << Source::Replace.new(start_offset, end_offset - 1, replacement)
+
           true
         end
 
@@ -166,7 +174,40 @@ def translatable_annotation?(node)
         def at_end_of_line?(node)
           end_offset = node.location.end_offset
           end_offset += 1 while (@ruby_bytes[end_offset] == " ".ord) && (end_offset < @ruby_bytes.size)
-          @ruby_bytes[end_offset] == LINE_BREAK
+          # Check if we're at a newline OR at the start of a comment
+          @ruby_bytes[end_offset] == LINE_BREAK || @ruby_bytes[end_offset] == "#".ord
+        end
+
+        # Check if the node has an RBS annotation comment (#:) after it
+        #: (Prism::Node) -> bool
+        def has_rbs_annotation?(node)
+          end_offset = node.location.end_offset
+          # Skip spaces
+          end_offset += 1 while (@ruby_bytes[end_offset] == " ".ord) && (end_offset < @ruby_bytes.size)
+          # Check if there's a comment starting with #:
+          @ruby_bytes[end_offset] == "#".ord && @ruby_bytes[end_offset + 1] == ":".ord
+        end
+
+        # Extract any trailing comment after the node
+        # Returns [comment_text, comment_end_offset] or [nil, nil] if no comment or RBS annotation
+        #: (Prism::Node) -> [String?, Integer?]
+        def extract_trailing_comment(node)
+          end_offset = node.location.end_offset
+          # Skip spaces
+          end_offset += 1 while (@ruby_bytes[end_offset] == " ".ord) && (end_offset < @ruby_bytes.size)
+          # Check if there's a comment
+          return [nil, nil] unless @ruby_bytes[end_offset] == "#".ord
+
+          # If it's an RBS annotation comment (#:), return nil to prevent translation
+          return [nil, nil] if @ruby_bytes[end_offset + 1] == ":".ord
+
+          # Find the end of the comment (end of line)
+          comment_start = end_offset
+          end_offset += 1 while @ruby_bytes[end_offset] != LINE_BREAK && end_offset < @ruby_bytes.size
+
+          # Extract the comment including the leading space and return the end offset
+          range = @ruby_bytes[comment_start...end_offset] #: as !nil
+          [" #{range.pack('C*')}", end_offset]
         end
 
         #: (Prism::Node, Prism::Node) -> String

test/spoom/sorbet/translate/sorbet_assertions_to_rbs_comments_test.rb

@@ -376,7 +376,10 @@ def test_does_not_translate_assertions_already_with_comments
             a = T.let(42, Integer) # as Integer
           RB
 
-          assert_equal(rb, rbi_to_rbs(rb))
+          # Now translates and preserves the comment
+          assert_equal(<<~RB, rbi_to_rbs(rb))
+            a = 42 #: Integer # as Integer
+          RB
         end
 
         def test_translate_cast_in_oneliners
@@ -539,6 +542,20 @@ def test_translate_options
           )
         end
 
+        def test_translate_with_trailing_comments
+          rb = <<~RB
+            a = T.let(3, Integer) # comment
+            b = T.cast(x, String) # another comment
+            T.must(y) # must comment
+          RB
+
+          assert_equal(<<~RB, rbi_to_rbs(rb))
+            a = 3 #: Integer # comment
+            b = x #: as String # another comment
+            y #: as !nil # must comment
+          RB
+        end
+
         private
 
         #: (