implemented builder pattern

creational/builder/builder.go

@@ -0,0 +1,99 @@
+package builder
+
+type PersonalComputer struct {
+	ramCap int
+	hddCap int
+	cpu    string
+	os     string
+	gpu    string
+}
+
+type PCBuilder interface {
+	SetRAM() PCBuilder
+	SetHDD() PCBuilder
+	SetCPU() PCBuilder
+	SetOS() PCBuilder
+	SetGPU() PCBuilder
+	GetPC() PersonalComputer
+}
+
+// Hoem edition pc builder
+type HomeEditionPCBuilder struct {
+	pc PersonalComputer
+}
+
+func (b *HomeEditionPCBuilder) SetRAM() PCBuilder {
+	b.pc.ramCap = 4
+	return b
+}
+
+func (b *HomeEditionPCBuilder) SetHDD() PCBuilder {
+	b.pc.hddCap = 500
+	return b
+}
+
+func (b *HomeEditionPCBuilder) SetCPU() PCBuilder {
+	b.pc.cpu = "i3"
+	return b
+}
+
+func (b *HomeEditionPCBuilder) SetOS() PCBuilder {
+	b.pc.os = "Windows 7 Home Edition"
+	return b
+}
+
+func (b *HomeEditionPCBuilder) SetGPU() PCBuilder {
+	b.pc.gpu = "Intel Graphic Card"
+	return b
+}
+
+func (b *HomeEditionPCBuilder) GetPC() PersonalComputer {
+	return b.pc
+}
+
+// Game edition pc builder
+type GameEditionPCBuilder struct {
+	pc PersonalComputer
+}
+
+func (b *GameEditionPCBuilder) SetRAM() PCBuilder {
+	b.pc.ramCap = 16
+	return b
+}
+
+func (b *GameEditionPCBuilder) SetHDD() PCBuilder {
+	b.pc.hddCap = 500
+	return b
+}
+
+func (b *GameEditionPCBuilder) SetCPU() PCBuilder {
+	b.pc.cpu = "i7"
+	return b
+}
+
+func (b *GameEditionPCBuilder) SetOS() PCBuilder {
+	b.pc.os = "Windows 7 Ultimate"
+	return b
+}
+
+func (b *GameEditionPCBuilder) SetGPU() PCBuilder {
+	b.pc.gpu = "AMD Radeon X80"
+	return b
+}
+
+func (b *GameEditionPCBuilder) GetPC() PersonalComputer {
+	return b.pc
+}
+
+//Manufacturer object which aware of build process for builder type
+type Manufacturer struct {
+	b PCBuilder
+}
+
+func (m *Manufacturer) SetBuilder(builder PCBuilder) {
+	m.b = builder
+}
+
+func (m *Manufacturer) ConstructPC() {
+	m.b.SetCPU().SetHDD().SetRAM().SetGPU().SetOS()
+}

creational/builder/builder_test.go

@@ -0,0 +1,33 @@
+package builder
+
+import "testing"
+
+func TestManufacturer(t *testing.T)  {
+	manufacturer := Manufacturer{}
+
+	homePCBuilder := &HomeEditionPCBuilder{}
+	manufacturer.SetBuilder(homePCBuilder)
+	manufacturer.ConstructPC()
+	homePC := homePCBuilder.GetPC()
+
+	if homePC.cpu != "i3" {
+		t.Errorf("Home edition PC cpu shoul be 'i3' but found %s", homePC.cpu)
+	}
+
+	if homePC.gpu != "Intel Graphic Card" {
+		t.Errorf("Home edition PC gpu shoul be 'Intel Graphic Card' but found %s", homePC.cpu)
+	}
+
+	gamePCBuilder := &GameEditionPCBuilder{}
+	manufacturer.SetBuilder(gamePCBuilder)
+	manufacturer.ConstructPC()
+	gamePC := gamePCBuilder.GetPC()
+
+	if gamePC.cpu != "i7" {
+		t.Errorf("Game edition PC cpu shoul be 'i7' but found %s", gamePC.cpu)
+	}
+
+	if gamePC.gpu != "AMD Radeon X80" {
+		t.Errorf("Game edition PC gpu shoul be 'Intel Graphic Card' but found %s", gamePC.cpu)
+	}
+}