func showStep()

in cmd/resgraph/viz/main.go [113:188]
64 lines of code
9 McCabe index (conditional complexity)

func showStep(w http.ResponseWriter, cl cloud.Cloud, idx int, step *testlib.Step) {
	outln, outf := wrapWriter(w)

	outln("<hr />")
	outf("<h2>Step %d</h2>", idx)

	if step.SetUp != nil {
		step.SetUp(cl)
	}

	result, err := plan.Do(context.Background(), cl, step.Graph)
	klog.Infof("plan.Do() = _, %v", err)

	outln("<pre>")
	outf("plan.Do() = _, %v", err)
	outln("</pre>")

	if err != nil {
		return
	}

	outln("<h3>Got graph</h3>")
	outln("")
	svg, err := dotSVG(graphviz.Do(result.Got))
	if err == nil {
		outln(svg)
	} else {
		klog.Infof("dotSVG(Got) = _, %v", err)
		outf("dotSVG() = %v", err)
	}
	outln("")

	outln("<h3>Want graph</h3>")
	outln("")
	svg, err = dotSVG(graphviz.Do(result.Want))
	if err == nil {
		outln(svg)
	} else {
		klog.Infof("dotSVG(Want) = _, %v", err)
		outf("dotSVG() = %v", err)
	}
	outln("")

	var viz exec.GraphvizTracer
	ex, err := exec.NewSerialExecutor(cl, result.Actions, exec.DryRunOption(false), exec.TracerOption(&viz))
	if err != nil {
		outf("NewSerialExecutor() = %v, want nil", err)
		return
	}

	execResult, err := ex.Run(context.Background())

	outln("<h3>Plan</h3>")
	outln("")
	svg, err = dotSVG(viz.String())
	if err == nil {
		outln(svg)
	} else {
		klog.Infof("dotSVG(viz) = _, %v", err)
		outf("<pre>dotSVG() = %v</pre>", err)
	}
	outln("")

	outln("<h3>Pending Actions</h3>\n")
	klog.Infof("Pending actions = %d", len(execResult.Pending))

	if len(execResult.Pending) == 0 {
		outln("No pending actions remain; all actions were executable.")
	} else {
		outln("<ol>")
		for _, item := range execResult.Pending {
			outf("<li>%+v</li>", item.Metadata())
		}
		outln("</ol>")
	}
}