Add test for instance variable ordering in DAP

PR #806 sorts instance variables by name before returning them. This
commit adds a test that verifies this functionality under the DAP
protocol.

Author: egiurleo

test/protocol/variables_test.rb

@@ -3,7 +3,7 @@
 require_relative "../support/protocol_test_case"
 
 module DEBUGGER__
-  class DAPVariablesTest < ProtocolTestCase
+  class DAPGlobalVariablesTest < ProtocolTestCase
     PROGRAM = <<~RUBY
       1| $a = 1
       2| $b = 2
@@ -18,19 +18,19 @@ def test_eval_evaluates_global_variables
         globals = gather_variables(type: "globals")
 
         # User defined globals
-        assert_includes(globals, { name: "$a", value: "1", type: "Integer" })
-        assert_includes(globals, { name: "$b", value: "2", type: "Integer" })
+        assert_includes(globals, { name: "$a", value: "1", type: "Integer", variablesReference: 0 })
+        assert_includes(globals, { name: "$b", value: "2", type: "Integer", variablesReference: 0 })
 
         # Ruby defined globals
-        assert_includes(globals, { name: "$VERBOSE", value: "false", type: "FalseClass" })
-        assert_includes(globals, { name: "$stdout", value: "#<IO:<STDOUT>>", type: "IO" })
+        assert_includes(globals, { name: "$VERBOSE", value: "false", type: "FalseClass", variablesReference: 0 })
+        assert_includes(globals, { name: "$stdout", value: "#<IO:<STDOUT>>", type: "IO", variablesReference: 0 })
 
         req_terminate_debuggee
       end
     end
   end
 
-  class CDPVariablesTest < ProtocolTestCase
+  class CDPGlobalVariablesTest < ProtocolTestCase
     PROGRAM = <<~RUBY
       1| $a = 1
       2| $b = 2
@@ -56,4 +56,30 @@ def test_eval_evaluates_global_variables
       end
     end
   end
+
+  class DAPInstanceVariableTest < ProtocolTestCase
+    PROGRAM = <<~RUBY
+      1| @a = 1
+      2| @c = 3
+      3| @b = 2
+      4| __LINE__
+    RUBY
+
+    def test_ordering_instance_variables
+      run_protocol_scenario PROGRAM, cdp: false do
+        req_add_breakpoint 4
+        req_continue
+
+        locals = gather_variables
+
+        variables_reference = locals.find { |local| local[:name] == "%self" }[:variablesReference]
+        res = send_dap_request 'variables', variablesReference: variables_reference
+
+        instance_vars = res.dig(:body, :variables)
+        assert_equal instance_vars.map { |var| var[:name] }, ["#class", "@a", "@b", "@c"]
+
+        req_terminate_debuggee
+      end
+    end
+  end
 end

test/support/protocol_test_case.rb

@@ -224,7 +224,7 @@ def gather_variables(frame_idx: 0, type: "locals")
 
         # get variables
         res = send_dap_request 'variables', variablesReference: locals_reference
-        res.dig(:body, :variables).map { |loc| { name: loc[:name], value: loc[:value], type: loc[:type] } }
+        res.dig(:body, :variables).map { |loc| { name: loc[:name], value: loc[:value], type: loc[:type], variablesReference: loc[:variablesReference] } }
       when 'chrome'
         current_frame = @crt_frames.first
         locals_scope = current_frame[:scopeChain].find { |f| f[:type] == type }