Add RSpec 'let' and 'let!' variable capture to scope parser (#107)

* Initial plan

* Add support for RSpec 'let' variables in scope parser

Co-authored-by: kwerle <23320+kwerle@users.noreply.github.com>

* Add support for RSpec 'let!' variables with comprehensive tests

Co-authored-by: kwerle <23320+kwerle@users.noreply.github.com>

* Improve code documentation for let command handling

Co-authored-by: kwerle <23320+kwerle@users.noreply.github.com>

* Update some test code

* Simplify let!

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: kwerle <23320+kwerle@users.noreply.github.com>
Co-authored-by: Kurt Werle <kurt@CircleW.org>

Author: Copilot

lib/ruby_language_server/scope_parser_commands/rspec_commands.rb

@@ -15,6 +15,22 @@ def on_it_command(line, args, rest)
         rspec_block_command('it', line, args, rest)
       end
 
+      def on_let_command(line, args, rest)
+        # Extract the variable name from the symbol (e.g., :foo -> foo)
+        # The rest array contains the extracted symbol values from extract_command_rest
+        var_name = rest.flatten.first
+        return unless var_name.is_a?(String)
+
+        # Extract the column from args structure: [:@ident, "let", [line, column]]
+        (_, _, (_, column)) = args
+
+        # Add the variable to the current scope
+        add_variable(var_name, line, column)
+      end
+
+      # let! is an eager version of let - alias it using send to avoid syntax issues
+      send(:alias_method, 'on_let!_command', :on_let_command)
+
       private
 
       def rspec_block_command(prefix, line, _args, rest)

spec/lib/ruby_language_server/scope_data/scope_spec.rb

@@ -52,16 +52,16 @@ def baz; end
     end
   end
 
-  # describe '.scopes_at' do
-  #   it 'should find the deepest scope' do
-  #     assert_equal([], root_scope.scopes_at(OpenStruct.new(line: 0)))
-  #     assert_equal([], root_scope.scopes_at(OpenStruct.new(line: 1)))
-  #     assert_equal(foo_scope, root_scope.scopes_at(OpenStruct.new(line: 2)).first)
-  #     assert_equal(bar_class_scope, root_scope.scopes_at(OpenStruct.new(line: 3)).first)
-  #     assert_equal(baz_method_scope, root_scope.scopes_at(OpenStruct.new(line: 6)).first)
-  #     assert_equal(nar_class_scope, root_scope.scopes_at(OpenStruct.new(line: 13)).first)
-  #     assert_equal(naz_method_scope, root_scope.scopes_at(OpenStruct.new(line: 16)).first)
-  #     assert_equal(RubyLanguageServer::ScopeData::Base::TYPE_BLOCK, root_scope.scopes_at(OpenStruct.new(line: 19)).first.class_type)
-  #   end
-  # end
+  describe '.scopes_at' do
+    it 'should find the deepest scope' do
+      assert_equal([], root_scope.self_and_descendants.for_line(0).where.not(class_type: 'root').to_a)
+      assert_equal([], root_scope.self_and_descendants.for_line(1).where.not(class_type: 'root').to_a)
+      assert_equal(foo_scope, root_scope.self_and_descendants.for_line(2).by_path_length.first)
+      assert_equal(bar_class_scope, root_scope.self_and_descendants.for_line(3).by_path_length.first)
+      assert_equal(baz_method_scope, root_scope.self_and_descendants.for_line(6).by_path_length.first)
+      assert_equal(nar_class_scope, root_scope.self_and_descendants.for_line(13).by_path_length.first)
+      assert_equal(naz_method_scope, root_scope.self_and_descendants.for_line(16).by_path_length.first)
+      assert_equal(RubyLanguageServer::ScopeData::Base::TYPE_BLOCK, root_scope.self_and_descendants.for_line(19).by_path_length.first.class_type)
+    end
+  end
 end

spec/lib/ruby_language_server/scope_parser_commands/rspec_commands_spec.rb

@@ -46,4 +46,50 @@
       assert_equal('context some context', context_block.name)
     end
   end
+
+  describe 'let variables' do
+    it 'should capture let variables in the appropriate scope' do
+      top_describe = @parser.root_scope.children.first
+      block = top_describe.children.first
+
+      # Check that 'foo' variable is in the top describe block
+      foo_variable = block.variables.find { |v| v.name == 'foo' }
+      refute_nil(foo_variable, 'Expected to find foo variable in top describe block')
+      assert_equal(2, foo_variable.line)
+    end
+
+    it 'should capture let variables in nested scopes' do
+      top_describe = @parser.root_scope.children.first
+      block = top_describe.children.first
+      some_thing_describe = block.children.find { |c| c.name == 'describe some thing' }
+      some_thing_block = some_thing_describe.children.first
+
+      # Check that 'common' variable is in the nested describe block
+      common_variable = some_thing_block.variables.find { |v| v.name == 'common' }
+      refute_nil(common_variable, 'Expected to find common variable in nested describe block')
+      assert_equal(5, common_variable.line)
+    end
+  end
+
+  describe 'let! variables' do
+    before do
+      @let_bang_code = <<-SOURCE
+      describe 'eager evaluation' do
+        let!(:eager_var) { 'eager_value' }
+      end
+      SOURCE
+      @let_bang_parser = RubyLanguageServer::ScopeParser.new(@let_bang_code)
+    end
+
+    it 'should capture let! variables' do
+      # Get the describe scope for 'eager evaluation', not the first one which is from another test
+      describe_scope = @let_bang_parser.root_scope.children.find { |c| c.name.include?('eager evaluation') }
+      block = describe_scope.children.first
+
+      # Check that 'eager_var' variable is captured
+      eager_variable = block.variables.find { |v| v.name == 'eager_var' }
+      refute_nil(eager_variable, 'Expected to find eager_var from let!')
+      assert_equal(2, eager_variable.line)
+    end
+  end
 end