Merge pull request #20 from bvwells/template_method

Implement template method #16

Author: bvwells

README.md

@@ -70,7 +70,7 @@ Name       | Description                               | Status
 [`Observer`](./behavioral/observer.go) | Define a one-to-many dependency between objects where a state change in one object results in all its dependents being notified and updated automatically. | Implemented
 [`State`](./behavioral/state.go) | Allow an object to alter its behavior when its internal state changes. The object will appear to change its class. |
 [`Strategy`](./behavioral/strategy.go) | Define a family of algorithms, encapsulate each one, and make them interchangeable. Strategy lets the algorithm vary independently from clients that use it. | Implemented
-[`Template Method`](./behavioral/template_method.go) | Define the skeleton of an algorithm in an operation, deferring some steps to subclasses. Template method lets subclasses redefine certain steps of an algorithm without changing the algorithm's structure. |
+[`Template Method`](./behavioral/template_method.go) | Define the skeleton of an algorithm in an operation, deferring some steps to subclasses. Template method lets subclasses redefine certain steps of an algorithm without changing the algorithm's structure. | Implemented
 [`Visitor`](./behavioral/visitor.go) | Represent an operation to be performed on the elements of an object structure. Visitor lets a new operation be defined without changing the classes of the elements on which it operates. | Implemented
 
 ## Go Versions Supported

behavioral/template_method.go

@@ -1 +1,76 @@
 package behavioral
+
+import (
+	"fmt"
+)
+
+// WorkerInterface defines an interface for a worker.
+type WorkerInterface interface {
+	GetUp()
+	EatBreakfast()
+	GoToWork()
+	Work()
+	ReturnHome()
+	Relax()
+	Sleep()
+}
+
+// Worker defines the worker.
+type Worker struct {
+	WorkerInterface
+}
+
+// NewWorker returns a new Worker.
+func NewWorker(w WorkerInterface) *Worker {
+	return &Worker{w}
+}
+
+// DailyRoutine is the template method for printing the workers daily routine.
+func (w *Worker) DailyRoutine() {
+	w.GetUp()
+	w.EatBreakfast()
+	w.GoToWork()
+	w.Work()
+	w.ReturnHome()
+	w.Relax()
+	w.Sleep()
+}
+
+// PostMan is a worker.
+type PostMan struct {
+}
+
+// GetUp prints what the postman does to get up.
+func (w *PostMan) GetUp() {
+	fmt.Fprintf(outputWriter, "Getting up\n")
+}
+
+// EatBreakfast prints what the postman does to eat breakfast.
+func (w *PostMan) EatBreakfast() {
+	fmt.Fprintf(outputWriter, "Eating pop tarts\n")
+}
+
+// GoToWork prints what the postman does to get to work.
+func (w *PostMan) GoToWork() {
+	fmt.Fprintf(outputWriter, "Cycle to work\n")
+}
+
+// Work prints what the postman does to work.
+func (w *PostMan) Work() {
+	fmt.Fprintf(outputWriter, "Post letters\n")
+}
+
+// ReturnHome prints what the postman does to get home.
+func (w *PostMan) ReturnHome() {
+	fmt.Fprintf(outputWriter, "Cycle home\n")
+}
+
+// Relax prints what the postman does to relax.
+func (w *PostMan) Relax() {
+	fmt.Fprintf(outputWriter, "Collect stamps\n")
+}
+
+// Sleep prints what the postman does to sleep.
+func (w *PostMan) Sleep() {
+	fmt.Fprintf(outputWriter, "Zzzzzzz\n")
+}

behavioral/template_method_test.go

@@ -0,0 +1,26 @@
+package behavioral
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTemplateMethod(t *testing.T) {
+
+	bufferOutputWriter := outputWriter
+	outputWriter = new(bytes.Buffer)
+	defer func() { outputWriter = bufferOutputWriter }()
+
+	worker := NewWorker(&PostMan{})
+	worker.DailyRoutine()
+
+	assert.Equal(t, "Getting up\n"+
+		"Eating pop tarts\n"+
+		"Cycle to work\n"+
+		"Post letters\n"+
+		"Cycle home\n"+
+		"Collect stamps\n"+
+		"Zzzzzzz\n", outputWriter.(*bytes.Buffer).String())
+}