Fix rename from constant definition sites

lib/ruby_indexer/lib/ruby_indexer/index.rb

@@ -41,6 +41,8 @@ def constant_name(node)
         case node
         when Prism::ConstantPathNode, Prism::ConstantReadNode, Prism::ConstantPathTargetNode
           node.full_name
+        when Prism::ConstantWriteNode, Prism::ConstantTargetNode
+          node.name.to_s
         end
       rescue Prism::ConstantPathNode::DynamicPartsInConstantPathError,
              Prism::ConstantPathNode::MissingNodesInConstantPathError

lib/ruby_indexer/test/index_test.rb

@@ -2262,6 +2262,12 @@ def test_constant_name
       node = Prism.parse("class Foo; end").value.statements.body.first.constant_path
       assert_equal("Foo", Index.constant_name(node))
 
+      node = Prism.parse("Foo = 1").value.statements.body.first
+      assert_equal("Foo", Index.constant_name(node))
+
+      node = Prism.parse("Foo, Bar = 1, 2").value.statements.body.first.lefts.first
+      assert_equal("Foo", Index.constant_name(node))
+
       node = Prism.parse(<<~RUBY).value.statements.body.first.constant_path
         class class Foo
         end

lib/ruby_lsp/requests/prepare_rename.rb

@@ -24,7 +24,13 @@ def perform
         node_context = RubyDocument.locate(
           @document.ast,
           char_position,
-          node_types: [Prism::ConstantReadNode, Prism::ConstantPathNode, Prism::ConstantPathTargetNode],
+          node_types: [
+            Prism::ConstantReadNode,
+            Prism::ConstantPathNode,
+            Prism::ConstantPathTargetNode,
+            Prism::ConstantWriteNode,
+            Prism::ConstantTargetNode,
+          ],
           code_units_cache: @document.code_units_cache,
         )
         target = node_context.node
@@ -39,7 +45,8 @@ def perform
           )
         end
 
-        range_from_location(target.location)
+        location = target.is_a?(Prism::ConstantWriteNode) ? target.name_loc : target.location
+        range_from_location(location)
       end
     end
   end

lib/ruby_lsp/requests/rename.rb

@@ -36,7 +36,13 @@ def perform
         node_context = RubyDocument.locate(
           @document.ast,
           char_position,
-          node_types: [Prism::ConstantReadNode, Prism::ConstantPathNode, Prism::ConstantPathTargetNode],
+          node_types: [
+            Prism::ConstantReadNode,
+            Prism::ConstantPathNode,
+            Prism::ConstantPathTargetNode,
+            Prism::ConstantWriteNode,
+            Prism::ConstantTargetNode,
+          ],
           code_units_cache: @document.code_units_cache,
         )
         target = node_context.node
@@ -51,7 +57,7 @@ def perform
           )
         end
 
-        target = target #: as Prism::ConstantReadNode | Prism::ConstantPathNode | Prism::ConstantPathTargetNode
+        target = target #: as Prism::ConstantReadNode | Prism::ConstantPathNode | Prism::ConstantPathTargetNode | Prism::ConstantWriteNode | Prism::ConstantTargetNode
 
         name = RubyIndexer::Index.constant_name(target)
         return unless name

test/requests/prepare_rename_expectations_test.rb

@@ -14,6 +14,35 @@ def run_expectations(source)
     RubyLsp::Requests::PrepareRename.new(document, position).perform
   end
 
+  def test_constant_definition
+    source = <<~RUBY
+      Foo = 1
+      Bar, Baz = 2, 3
+    RUBY
+    uri = URI("file:///fake.rb")
+    document = RubyLsp::RubyDocument.new(source: source, version: 1, uri: uri, global_state: @global_state)
+
+    range = RubyLsp::Requests::PrepareRename.new(
+      document,
+      { line: 0, character: 1 },
+    ).perform #: as !nil
+
+    assert_equal(0, range.start.line)
+    assert_equal(0, range.start.character)
+    assert_equal(0, range.end.line)
+    assert_equal(3, range.end.character)
+
+    range = RubyLsp::Requests::PrepareRename.new(
+      document,
+      { line: 1, character: 1 },
+    ).perform #: as !nil
+
+    assert_equal(1, range.start.line)
+    assert_equal(0, range.start.character)
+    assert_equal(1, range.end.line)
+    assert_equal(3, range.end.character)
+  end
+
   private
 
   def default_position

test/requests/rename_test.rb

@@ -105,8 +105,65 @@ class RenameMe
     assert_equal("NewMe", untitled_change.edits[0].new_text)
   end
 
+  def test_renaming_from_constant_definition
+    source = <<~RUBY
+      Foo = 1
+      Foo
+    RUBY
+    expected = <<~RUBY
+      Renamed = 1
+      Renamed
+    RUBY
+
+    assert_equal(expected, rename_source(source, { line: 0, character: 1 }))
+  end
+
+  def test_renaming_from_constant_target
+    source = <<~RUBY
+      Foo, Bar = 1, 2
+      Foo
+      Bar
+    RUBY
+    expected = <<~RUBY
+      Renamed, Bar = 1, 2
+      Renamed
+      Bar
+    RUBY
+
+    assert_equal(expected, rename_source(source, { line: 0, character: 1 }))
+  end
+
   private
 
+  def rename_source(source, position)
+    source = source.dup
+    global_state = RubyLsp::GlobalState.new
+    uri = URI("untitled:constant-definition")
+    global_state.index.index_single(uri, source)
+    store = RubyLsp::Store.new(global_state)
+    document = store.set(
+      uri: uri,
+      source: source,
+      version: 1,
+      language_id: :ruby,
+    )
+
+    workspace_edit = RubyLsp::Requests::Rename.new(
+      global_state,
+      store,
+      document,
+      { position: position, newName: "Renamed" },
+    ).perform #: as !nil
+
+    document.push_edits(
+      workspace_edit.changes.fetch(uri.to_s).map do |edit|
+        { range: edit.range.to_hash.transform_values(&:to_hash), text: edit.new_text }
+      end,
+      version: 2,
+    )
+    document.source
+  end
+
   def expect_renames(fixture_path, new_fixture_path, expected, position, new_name)
     source = File.read(fixture_path)
     global_state = RubyLsp::GlobalState.new