Use overridableExpectationsOption instead of introducing new constructor

Author: styeung

gomock/callset.go

@@ -29,7 +29,7 @@ type callSet struct {
 	expectedMu *sync.Mutex
 	// Calls that have been exhausted.
 	exhausted map[callSetKey][]*Call
-	// when set to true,
+	// when set to true, existing call expectations are overridden when new call expectations are made
 	allowOverride bool
 }
 
@@ -68,7 +68,6 @@ func (cs callSet) Add(call *Call) {
 		m = cs.exhausted
 	}
 	if cs.allowOverride {
-		delete(m, key)
 		m[key] = make([]*Call, 0)
 	}
 

gomock/controller.go

@@ -108,30 +108,21 @@ func NewController(t TestReporter, opts ...ControllerOption) *Controller {
 	return ctrl
 }
 
-// ControllerOption configures how a Controller should behave. Currently
-// there are no implementations of it.
+// ControllerOption configures how a Controller should behave.
 type ControllerOption interface {
 	apply(*Controller)
 }
 
-// NewOverridableController returns a new Controller that allows for overridable call expectations
-func NewOverridableController(t TestReporter) *Controller {
-	h, ok := t.(TestHelper)
-	if !ok {
-		h = &nopTestHelper{t}
-	}
-	ctrl := &Controller{
-		T:             h,
-		expectedCalls: newOverridableCallSet(),
-	}
-	if c, ok := isCleanuper(ctrl.T); ok {
-		c.Cleanup(func() {
-			ctrl.T.Helper()
-			ctrl.finish(true, nil)
-		})
-	}
+type overridableExpectationsOption struct{}
 
-	return ctrl
+// WithOverridableExpectations allows for overridable call expectations
+// i.e., subsequent call expectations override existing call expectations
+func WithOverridableExpectations() overridableExpectationsOption {
+	return overridableExpectationsOption{}
+}
+
+func (o overridableExpectationsOption) apply(ctrl *Controller) {
+	ctrl.expectedCalls = newOverridableCallSet()
 }
 
 type cancelReporter struct {

gomock/example_test.go

@@ -49,9 +49,9 @@ func ExampleCall_DoAndReturn_captureArguments() {
 	// Output: I'm sleepy foo
 }
 
-func ExampleCall_OverridableController_HappyPath() {
+func ExampleCall_WithOverridableExpectations() {
 	t := &testing.T{} // provided by test
-	ctrl := gomock.NewOverridableController(t)
+	ctrl := gomock.NewController(t, gomock.WithOverridableExpectations())
 	mockIndex := NewMockFoo(ctrl)
 	var s string
 

gomock/overridable_controller_test.go

@@ -7,7 +7,7 @@ import (
 )
 
 func TestEcho_NoOverride(t *testing.T) {
-	ctrl := gomock.NewOverridableController(t)
+	ctrl := gomock.NewController(t, gomock.WithOverridableExpectations())
 	mockIndex := NewMockFoo(ctrl)
 
 	mockIndex.EXPECT().Bar(gomock.Any()).Return("foo")
@@ -19,7 +19,7 @@ func TestEcho_NoOverride(t *testing.T) {
 }
 
 func TestEcho_WithOverride_BaseCase(t *testing.T) {
-	ctrl := gomock.NewOverridableController(t)
+	ctrl := gomock.NewController(t, gomock.WithOverridableExpectations())
 	mockIndex := NewMockFoo(ctrl)
 
 	// initial expectation set