Fix same resource test

pkg/engine/lifeycletest/pulumi_test.go

@@ -3210,11 +3210,11 @@ func TestResoucesWithSames(t *testing.T) {
 	expected = resource.NewPropertyMapFromMap(map[string]interface{}{
 		"X": "Y",
 	})
-	assert.Equal(t, expected, snap.Resources[1].Outputs)
+	assert.Equal(t, expected, snap.Resources[2].Outputs)
 
 	expected = resource.NewPropertyMapFromMap(map[string]interface{}{
 		"foo": "bar",
 		"zed": 24,
 	})
-	assert.Equal(t, expected, snap.Resources[2].Outputs)
+	assert.Equal(t, expected, snap.Resources[1].Outputs)
 }

pkg/resource/deploy/plan.go

@@ -163,6 +163,37 @@ func (rp *ResourcePlan) diffPropertyDependencies(a, b map[resource.PropertyKey][
 	return nil
 }
 
+// This is similar to ResourcePlan.checkGoal but for the case we're we don't have a goal saved. This simple checks that we're not changing anything.
+func checkMissingPlan(
+	oldState *resource.State,
+	newInputs resource.PropertyMap,
+	programGoal *resource.Goal) error {
+
+	// We new up a fake ResourcePlan that matches the old state and then simply call checkGoal on it.
+	goal := &GoalPlan{
+		Type:                    oldState.Type,
+		Name:                    oldState.URN.Name(),
+		Custom:                  oldState.Custom,
+		Adds:                    nil,
+		Deletes:                 nil,
+		Updates:                 nil,
+		Parent:                  oldState.Parent,
+		Protect:                 oldState.Protect,
+		Dependencies:            oldState.Dependencies,
+		Provider:                oldState.Provider,
+		PropertyDependencies:    oldState.PropertyDependencies,
+		DeleteBeforeReplace:     nil,
+		IgnoreChanges:           nil,
+		AdditionalSecretOutputs: oldState.AdditionalSecretOutputs,
+		Aliases:                 oldState.Aliases,
+		ID:                      "",
+		CustomTimeouts:          oldState.CustomTimeouts,
+	}
+
+	rp := ResourcePlan{Goal: goal}
+	return rp.checkGoal(oldState.Outputs, newInputs, programGoal)
+}
+
 func (rp *ResourcePlan) checkGoal(
 	oldOutputs resource.PropertyMap,
 	newInputs resource.PropertyMap,

pkg/resource/deploy/step.go

@@ -1170,9 +1170,11 @@ func (op StepOp) Suffix() string {
 func (op StepOp) ConstrainedTo(constraint StepOp) bool {
 	var allowed []StepOp
 	switch constraint {
-	case OpSame, OpCreate, OpDelete, OpRead, OpReadReplacement, OpRefresh, OpReadDiscard, OpDiscardReplaced,
+	case OpSame, OpDelete, OpRead, OpReadReplacement, OpRefresh, OpReadDiscard, OpDiscardReplaced,
 		OpRemovePendingReplace, OpImport, OpImportReplacement:
 		allowed = []StepOp{constraint}
+	case OpCreate:
+		allowed = []StepOp{OpSame, OpCreate}
 	case OpUpdate:
 		allowed = []StepOp{OpSame, OpUpdate}
 	case OpReplace, OpCreateReplacement, OpDeleteReplaced:

pkg/resource/deploy/step_generator.go

@@ -194,7 +194,9 @@ func (sg *stepGenerator) GenerateSteps(event RegisterResourceEvent) ([]Step, res
 				}
 				resourcePlan.Ops = resourcePlan.Ops[1:]
 			} else {
-				return nil, result.Errorf("%v is not allowed by the plan: no steps were expected for this resource", s.Op())
+				if !s.Op().ConstrainedTo(OpSame) {
+					return nil, result.Errorf("%v is not allowed by the plan: no steps were expected for this resource", s.Op())
+				}
 			}
 		}
 
@@ -310,13 +312,17 @@ func (sg *stepGenerator) generateSteps(event RegisterResourceEvent) ([]Step, res
 	sg.deployment.newPlans.set(urn, newResourcePlan)
 
 	// If there is a plan for this resource, validate that the program goal conforms to the plan.
+	// If theres no plan for this resource check that nothing has been changed.
 	if sg.deployment.plan != nil {
 		resourcePlan, ok := sg.deployment.plan[urn]
 		if !ok {
-			return nil, result.Errorf("resource not found in plan")
+			if err := checkMissingPlan(old, inputs, goal); err != nil {
-		}
+				return nil, result.FromError(fmt.Errorf("resource violates plan: %w", err))
-		if err := resourcePlan.checkGoal(oldOutputs, inputs, goal); err != nil {
+			}
-			return nil, result.FromError(fmt.Errorf("resource violates plan: %w", err))
+		} else {
+			if err := resourcePlan.checkGoal(oldOutputs, inputs, goal); err != nil {
+				return nil, result.FromError(fmt.Errorf("resource violates plan: %w", err))
+			}
 		}
 	}