func()

in fixtures.go [368:429]

• 49 lines of code
• 12 McCabe index (conditional complexity)

func (t *TestVM) CreateDerivativeVM(name string) (*TestVM, error) {
	t.testWorkflow.counter++
	stepSuffix := fmt.Sprintf("%s-%d", t.name, t.testWorkflow.counter)
	vmname := fmt.Sprintf("derivative-%s", name)

	// Stop the source VM.
	lastStep, err := t.testWorkflow.getLastStepForVM(t.name)
	if err != nil {
		return nil, fmt.Errorf("failed to resolve last step")
	}
	stopStep, err := t.testWorkflow.addStopStep(stepSuffix, t.name)
	if err != nil {
		return nil, err
	}
	if err := t.testWorkflow.wf.AddDependency(stopStep, lastStep); err != nil {
		return nil, err
	}

	// Wait for the source VM to stop.
	waitStopStep, err := t.testWorkflow.addWaitStoppedStep("stopped-"+stepSuffix, t.name)
	if err != nil {
		return nil, err
	}
	if err := t.testWorkflow.wf.AddDependency(waitStopStep, stopStep); err != nil {
		return nil, err
	}

	// Now detach the boot disk from the source VM.
	detachStepName := fmt.Sprintf("detach-disk-%s", stepSuffix)
	detachDiskStep, err := t.testWorkflow.appendDetachDiskStep(detachStepName, t.name, []string{t.name})
	if err != nil {
		return nil, err
	}
	if err := t.testWorkflow.wf.AddDependency(detachDiskStep, waitStopStep); err != nil {
		return nil, err
	}

	// Create a new instance using the original boot disk.
	daisyInst := &daisy.Instance{}
	bootDisk := &compute.Disk{Name: t.name}
	createVMStep, i, err := t.testWorkflow.addNewVMStep([]*compute.Disk{bootDisk}, daisyInst)
	if err != nil {
		return nil, err
	}
	if err := t.testWorkflow.wf.AddDependency(createVMStep, detachDiskStep); err != nil {
		return nil, err
	}

	// Override the name with the derivative name.
	i.Name = vmname

	// Add wait step for the new VM.
	waitStep, err := t.testWorkflow.addWaitStep(vmname, vmname)
	if err != nil {
		return nil, err
	}
	if err := t.testWorkflow.wf.AddDependency(waitStep, createVMStep); err != nil {
		return nil, err
	}

	return &TestVM{name: vmname, testWorkflow: t.testWorkflow, instance: i}, nil
}