Initial commit with examples and tests

Signed-off-by: Nikki Attea <[email protected]>

go.mod

@@ -0,0 +1,10 @@
+module github.com/nikkixdev/beer-testing
+
+go 1.13
+
+require (
+	github.com/kr/pretty v0.1.0 // indirect
+	github.com/sirupsen/logrus v1.4.2
+	github.com/stretchr/testify v1.4.0
+	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
+)

go.sum

@@ -0,0 +1,29 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sirupsen/logrus v1.4.2 h1:SPIRibHv4MatM3XXNO2BJeFLZwZ2LvZgfQ5+UNI2im4=
+github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
+github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.1.1 h1:2vfRuCMp5sSVIDSqO8oNnWJq7mPa6KVP3iPIwFBuy8A=
+github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+golang.org/x/sys v0.0.0-20190422165155-953cdadca894 h1:Cz4ceDQGXuKRnVBDTS23GTn/pU5OE2C0WrNTOYK1Uuc=
+golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
+gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

main.go

@@ -0,0 +1,183 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/sirupsen/logrus"
+)
+
+// Cart represents a shopping cart.
+type Cart struct {
+	Cases []*Case
+}
+
+// Case represents a case of beer.
+type Case struct {
+	Count int
+	Beer  *Beer
+	Price float64
+}
+
+// Beer represents a type of beer.
+type Beer struct {
+	Brand  string
+	Name   string
+	Ounces float64
+}
+
+// NewCart initializes a new shopping cart.
+func NewCart() *Cart {
+	return &Cart{}
+}
+
+// AddCase adds a case of beer to the shopping cart.
+func (c *Cart) AddCase(beerCase *Case) {
+	c.Cases = append(c.Cases, beerCase)
+}
+
+// Subtotal calculates the subtotal of the shopping cart.
+func (c *Cart) Subtotal() float64 {
+	var subtotal float64
+	for _, beerCase := range c.Cases {
+		subtotal += beerCase.Price
+	}
+	return subtotal
+}
+
+// ProcessPayment sends the total to an external payment api.
+func ProcessPayment(paymentServer string, total float64) ([]byte, error) {
+	b, _ := json.Marshal(total)
+	resp, err := http.Post(paymentServer, "application/json", bytes.NewBuffer(b))
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode >= 400 {
+		return nil, fmt.Errorf("payment server error: %d", resp.StatusCode)
+	}
+	return ioutil.ReadAll(resp.Body)
+}
+
+// PlaceOrder places the order in the warehouse.
+func (o *OrderHandler) PlaceOrder(ctx context.Context, cart *Cart) error {
+	o.ProcessedOrders = append(o.ProcessedOrders, cart)
+	return nil
+}
+
+// OrderHandler represents a concurrent order handler.
+type OrderHandler struct {
+	ProcessedOrders []*Cart
+	messageChan     chan interface{}
+}
+
+var logger = logrus.WithFields(logrus.Fields{
+	"component": "beer",
+})
+
+// startOrderHandler listens to the message channel and handles incoming orders.
+func (o *OrderHandler) startOrderHandler(ctx context.Context) {
+	for {
+		msg, ok := <-o.messageChan
+		if !ok {
+			logger.Debug("message channel closed")
+			return
+		}
+
+		cart, ok := msg.(*Cart)
+		if ok {
+			if err := o.PlaceOrder(ctx, cart); err != nil {
+				logger.WithError(err).Error("error placing order")
+				continue
+			}
+			logger.Info("successfully placed order")
+			continue
+		}
+
+		logger.WithField("msg", msg).Errorf("received invalid message on message channel")
+	}
+}
+
+// Subscription represents a shopping cart.
+type Subscription struct {
+	cart        *Cart
+	interval    time.Duration
+	messageChan chan interface{}
+	mu          sync.Mutex
+}
+
+// GetCart safely retrieves the subscriptions shopping cart.
+func (s *Subscription) GetCart() *Cart {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.cart
+}
+
+// SetCart safely sets the subscriptions shopping cart.
+func (s *Subscription) SetCart(c *Cart) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.cart = c
+}
+
+// GetInterval safely retrieves the subscriptions interval.
+func (s *Subscription) GetInterval() time.Duration {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.interval
+}
+
+// SetInterval safely sets the subscriptions interval.
+func (s *Subscription) SetInterval(t time.Duration) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.interval = t
+}
+
+// startSubscriptionTimer starts a timer and fires the cart to the
+// order handler when the order is ready.
+func (s *Subscription) startSubscriptionTimer(ctx context.Context) {
+	ticker := time.NewTicker(s.GetInterval())
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			s.messageChan <- s.GetCart()
+		}
+	}
+}
+
+// FixtureBeer creates a Beer fixture for use in test.
+func FixtureBeer(brand string, name string, ounces float64) *Beer {
+	return &Beer{
+		Brand:  brand,
+		Name:   name,
+		Ounces: ounces,
+	}
+}
+
+// FixtureCase creates a Case fixture for use in test.
+func FixtureCase(count int, beer *Beer, price float64) *Case {
+	return &Case{
+		Count: count,
+		Beer:  beer,
+		Price: price,
+	}
+}
+
+// FixtureCart creates a Cart fixture for use in test.
+func FixtureCart() *Cart {
+	return &Cart{
+		Cases: []*Case{FixtureCase(4, FixtureBeer("Duvel", "Tripel Hop", 11.0), 14)},
+	}
+}
+
+func main() {}

main_test.go

@@ -0,0 +1,158 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAddCaseTesting(t *testing.T) {
+	cart := NewCart()
+	if len(cart.Cases) != 0 {
+		t.Fatal("expected empty cart")
+	}
+
+	blueLight := FixtureBeer("Labatt", "Blue Light", 12.0)
+	cart.AddCase(FixtureCase(6, blueLight, 10.99))
+	if len(cart.Cases) != 1 {
+		t.Fatal("expected 1 case in cart")
+	}
+}
+
+func TestAddCaseAssert(t *testing.T) {
+	cart := NewCart()
+	assert.Equal(t, 0, len(cart.Cases))
+
+	blueLight := FixtureBeer("Labatt", "Blue Light", 12.0)
+	cart.AddCase(FixtureCase(6, blueLight, 10.99))
+	assert.Equal(t, 1, len(cart.Cases))
+}
+
+func TestSubtotal(t *testing.T) {
+	cart := NewCart()
+	assert.Equal(t, 0, len(cart.Cases))
+
+	duvelHop := FixtureBeer("Duvel", "Tripel Hop", 11.0)
+	cart.AddCase(FixtureCase(4, duvelHop, 14.99))
+	blueLight := FixtureBeer("Labatt", "Blue Light", 12.0)
+	cart.AddCase(FixtureCase(30, blueLight, 24.99))
+	assert.Equal(t, 39.98, cart.Subtotal())
+}
+
+func TestSubtotalSuite(t *testing.T) {
+	testCases := []struct {
+		name     string
+		cart     *Cart
+		subtotal float64
+	}{
+		{
+			name:     "Empty cart",
+			cart:     &Cart{},
+			subtotal: 0,
+		},
+		{
+			name: "Party time",
+			cart: &Cart{Cases: []*Case{
+				FixtureCase(4, FixtureBeer("Duvel", "Tripel Hop", 11.0), 14.99),
+				FixtureCase(30, FixtureBeer("Labatt", "Blue Light", 12.0), 24.99),
+				FixtureCase(30, FixtureBeer("Labatt", "Blue Light", 12.0), 24.99),
+			}},
+			subtotal: 64.97,
+		},
+		{
+			name: "Negative",
+			cart: &Cart{Cases: []*Case{
+				FixtureCase(4, FixtureBeer("Duvel", "Tripel Hop", 11.0), -14),
+				FixtureCase(30, FixtureBeer("Labatt", "Blue Light", 12.0), 24),
+			}},
+			subtotal: 10.00,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.subtotal, tc.cart.Subtotal())
+		})
+	}
+}
+
+func TestProcessPayment(t *testing.T) {
+	testCases := []struct {
+		name          string
+		handler       http.HandlerFunc
+		expectedError error
+		expectedBody  []byte
+	}{
+		{
+			name: "OK",
+			handler: func(w http.ResponseWriter, r *http.Request) {
+				w.Write([]byte(`OK`))
+				w.WriteHeader(http.StatusOK)
+			},
+			expectedError: nil,
+			expectedBody:  []byte(`OK`),
+		},
+		{
+			name: "Internal server error",
+			handler: func(w http.ResponseWriter, r *http.Request) {
+				w.WriteHeader(http.StatusInternalServerError)
+			},
+			expectedError: fmt.Errorf("payment server error: %d", http.StatusInternalServerError),
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			ts := httptest.NewServer(http.HandlerFunc(tc.handler))
+			defer ts.Close()
+			body, err := ProcessPayment(ts.URL, 21.11)
+			assert.Equal(t, tc.expectedError, err)
+			assert.Equal(t, tc.expectedBody, body)
+		})
+	}
+}
+
+func TestStartSubscriptionTimer(t *testing.T) {
+	ctx := context.Background()
+	cart1 := &Cart{Cases: []*Case{FixtureCase(4, FixtureBeer("Duvel", "Tripel Hop", 11.0), 14)}}
+	cart2 := &Cart{Cases: []*Case{FixtureCase(30, FixtureBeer("Labatt", "Blue Light", 12.0), 24)}}
+	subscription := &Subscription{
+		cart:        cart1,
+		interval:    time.Duration(1) * time.Second,
+		messageChan: make(chan interface{}),
+	}
+
+	go subscription.startSubscriptionTimer(ctx)
+	msg := <-subscription.messageChan
+	order, ok := msg.(*Cart)
+	if !ok {
+		t.Fatal("received invalid message on message channel")
+	}
+	assert.Equal(t, cart1, order)
+
+	subscription.SetCart(cart2)
+	msg = <-subscription.messageChan
+	order, ok = msg.(*Cart)
+	if !ok {
+		t.Fatal("received invalid message on message channel")
+	}
+	assert.Equal(t, cart2, order)
+}
+
+func TestStartOrderHandler(t *testing.T) {
+	handler := &OrderHandler{
+		messageChan: make(chan interface{}),
+	}
+	go handler.startOrderHandler(context.Background())
+	assert.Equal(t, 0, len(handler.ProcessedOrders))
+
+	handler.messageChan <- FixtureCart()
+	handler.messageChan <- FixtureCart()
+	handler.messageChan <- FixtureCase(30, FixtureBeer("Labatt", "Blue Light", 12.0), 24)
+	assert.Equal(t, 2, len(handler.ProcessedOrders))
+}