Implement OP_GETCONST

feature_test.go

@@ -60,6 +60,14 @@ func (feat *RubyFeature) thereShouldReturnFalse() error {
 	return nil
 }
 
+func (feat *RubyFeature) thereShouldReturnNil() error {
+	if feat.ret != nil {
+		return fmt.Errorf("expected nil, got %T", feat.ret)
+	}
+
+	return nil
+}
+
 func (feat *RubyFeature) thereShouldReturnString(expected string) error {
 	actual, ok := feat.ret.(string)
 	if !ok {
@@ -96,6 +104,7 @@ func InitializeScenario(s *godog.ScenarioContext) {
 	s.Step(`^there should return integer (-?\d+)$`, feat.thereShouldReturnInteger)
 	s.Step(`^there should return true$`, feat.thereShouldReturnTrue)
 	s.Step(`^there should return false$`, feat.thereShouldReturnFalse)
+	s.Step(`^there should return nil$`, feat.thereShouldReturnNil)
 	s.Step(`^there should return string "([^"]*)"$`, feat.thereShouldReturnString)
 	s.Step(`^there should return symbol "([^"]*)"$`, feat.thereShouldReturnSymbol)
 }

features/constant.feature

@@ -0,0 +1,7 @@
+Feature: Constant
+  Scenario: I can get non existing constant
+    When I execute ruby code:
+      """
+      MY_CONSTANT
+      """
+    Then there should return nil

irep.go

@@ -81,6 +81,10 @@ func (ir *iRep) Execute(state *State) (Value, error) {
 			a := ir.iSeq.ReadB()
 			b := ir.iSeq.ReadB()
 			regs[offset+int(a)] = ir.syms[b]
+		case opGetConst:
+			a := ir.iSeq.ReadB()
+			b := ir.iSeq.ReadB()
+			regs[a] = state.GetConst(ir.syms[b])
 		case opSelfSend:
 			a := ir.iSeq.ReadB()
 			b := ir.iSeq.ReadB()

variable.go

@@ -0,0 +1,5 @@
+package mruby
+
+func (mrb *State) GetConst(sym Symbol) Value {
+	return nil
+}