Fix extracting a method without another declaration to anchor replacement (#2429)

Author: vinistock

lib/ruby_lsp/requests/code_action_resolve.rb

@@ -207,27 +207,43 @@ def refactor_method
 
         # Find the closest method declaration node, so that we place the refactor in a valid position
         node_context = RubyDocument.locate(@document.parse_result.value, start_index, node_types: [Prism::DefNode])
-        closest_def = T.cast(node_context.node, Prism::DefNode)
-        return Error::InvalidTargetRange if closest_def.nil?
+        closest_node = node_context.node
+        return Error::InvalidTargetRange unless closest_node
 
-        end_keyword_loc = closest_def.end_keyword_loc
-        return Error::InvalidTargetRange if end_keyword_loc.nil?
+        target_range = if closest_node.is_a?(Prism::DefNode)
+          end_keyword_loc = closest_node.end_keyword_loc
+          return Error::InvalidTargetRange unless end_keyword_loc
 
-        end_line = end_keyword_loc.end_line - 1
-        character = end_keyword_loc.end_column
-        indentation = " " * end_keyword_loc.start_column
-        target_range = {
-          start: { line: end_line, character: character },
-          end: { line: end_line, character: character },
-        }
+          end_line = end_keyword_loc.end_line - 1
+          character = end_keyword_loc.end_column
+          indentation = " " * end_keyword_loc.start_column
 
-        new_method_source = <<~RUBY.chomp
+          new_method_source = <<~RUBY.chomp
 
 
-          #{indentation}def #{NEW_METHOD_NAME}
-          #{indentation}  #{extracted_source}
-          #{indentation}end
-        RUBY
+            #{indentation}def #{NEW_METHOD_NAME}
+            #{indentation}  #{extracted_source}
+            #{indentation}end
+          RUBY
+
+          {
+            start: { line: end_line, character: character },
+            end: { line: end_line, character: character },
+          }
+        else
+          new_method_source = <<~RUBY
+            #{indentation}def #{NEW_METHOD_NAME}
+            #{indentation}  #{extracted_source.gsub("\n", "\n  ")}
+            #{indentation}end
+
+          RUBY
+
+          line = [0, source_range.dig(:start, :line) - 1].max
+          {
+            start: { line: line, character: source_range.dig(:start, :character) },
+            end: { line: line, character: source_range.dig(:start, :character) },
+          }
+        end
 
         Interface::CodeAction.new(
           title: CodeActions::EXTRACT_TO_METHOD_TITLE,

test/expectations/code_action_resolve/extract_method_script.exp.json

@@ -0,0 +1,60 @@
+{
+    "params": {
+        "kind": "refactor.extract",
+        "title": "Refactor: Extract Method",
+        "data": {
+            "range": {
+                "start": {
+                    "line": 0,
+                    "character": 0
+                },
+                "end": {
+                    "line": 2,
+                    "character": 6
+                }
+            },
+            "uri": "file:///fake"
+        }
+    },
+    "result": {
+        "title": "Refactor: Extract Method",
+        "edit": {
+            "documentChanges": [
+                {
+                    "textDocument": {
+                        "uri": "file:///fake",
+                        "version": null
+                    },
+                    "edits": [
+                        {
+                            "range": {
+                                "start": {
+                                    "line": 0,
+                                    "character": 0
+                                },
+                                "end": {
+                                    "line": 0,
+                                    "character": 0
+                                }
+                            },
+                            "newText": "def new_method\n  a = 5 + 2\n  a * 10\n  \nend\n\n"
+                        },
+                        {
+                            "range": {
+                                "start": {
+                                    "line": 0,
+                                    "character": 0
+                                },
+                                "end": {
+                                    "line": 2,
+                                    "character": 6
+                                }
+                            },
+                            "newText": "new_method"
+                        }
+                    ]
+                }
+            ]
+        }
+    }
+}

test/fixtures/extract_method_script.rb

@@ -0,0 +1,2 @@
+a = 5 + 2
+a * 10