first commit.

way too late.

doorman_test.go

@@ -0,0 +1,215 @@
+package doorman
+
+import (
+	"encoding/json"
+	"fmt"
+	"math"
+	"net/http"
+	"net/http/httptest"
+	"reflect"
+	"testing"
+
+	"github.com/didiercrunch/doorman/shared"
+	"gopkg.in/mgo.v2/bson"
+)
+
+func assertIsAbout(t *testing.T, expected, received float64) {
+	if math.Abs(expected-received) > epsilon {
+		t.Error("received", received, "but expected", expected)
+	}
+}
+
+func assertIsNotAbout(t *testing.T, expected, received float64) {
+	if math.Abs(expected-received) < epsilon {
+		t.Error("received", received, "but expected something different than", expected)
+	}
+}
+
+var oid = "507f1f77bcf86cd799439011"
+
+func TestIsZero(t *testing.T) {
+	if !IsZero(epsilon / 2) {
+		t.Error()
+	}
+
+	if !IsZero(-epsilon / 2) {
+		t.Error()
+	}
+	if IsZero(epsilon * 1.5) {
+		t.Error()
+	}
+	if IsZero(-epsilon * 1.5) {
+		t.Error()
+	}
+}
+
+func TestIsEqual(t *testing.T) {
+	if !IsEqual(1.0, 1.0+epsilon/2) {
+		t.Error()
+	}
+	if IsEqual(1.0, 1.0+epsilon*1.5) {
+		t.Error()
+	}
+}
+
+func TestValidate(t *testing.T) {
+	w := &Doorman{}
+	if w.Validate().Error() != "not initiated" {
+		t.Error()
+	}
+
+	w = &Doorman{Probabilities: []float64{0.5, 0.75}}
+	if w.Validate().Error() != "The sum of probabilities is not one" {
+		t.Error()
+	}
+
+	w = &Doorman{Probabilities: []float64{0.25, 0.75}}
+	if w.Validate() != nil {
+		t.Error()
+	}
+
+	w = &Doorman{Probabilities: []float64{0.2500000000000002, 0.75}}
+	if w.Validate() != nil {
+		t.Error()
+	}
+}
+
+func TestGetCase(t *testing.T) {
+	w := NewDoorman(bson.NewObjectId(), []float64{0.25, 0.5, 0.25})
+	if c := w.GetCase(0); c != 0 {
+		t.Error("expected 0 but received", c)
+	}
+
+	if c := w.GetCase(1); c != 2 {
+		t.Error("expected 2 but received", c)
+	}
+}
+
+func TestGetCaseCoroutineSafety(t *testing.T) {
+	w := NewDoorman(bson.NewObjectId(), []float64{0.25, 0.5, 0.25})
+	i := 0
+	w.wg.Add(1)
+	go func() {
+		i++
+		w.wg.Done()
+	}()
+	w.GetCase(0)
+	if i != 1 {
+		t.Error("error with goroutine safety")
+	}
+}
+
+func TestGenerateRandomProbabilityFromBitSlice(t *testing.T) {
+	w := new(Doorman)
+	assertIsAbout(t, 0.5, w.GenerateRandomProbabilityFromInteger(1))
+
+	assertIsAbout(t, 0.5+0*0.25+1*0.125, w.GenerateRandomProbabilityFromInteger(5))
+
+	assertIsAbout(t, 1, w.GenerateRandomProbabilityFromInteger(math.MaxUint64))
+}
+
+func TestHash(t *testing.T) {
+	m := []byte("doormen are great")
+	w := new(Doorman)
+	var expt uint64 = 0x3973fc1b3e324215
+	result := w.Hash(m)
+
+	if result != expt {
+		t.Error(fmt.Sprintf("bad hashing, expected: %x, result: %x", expt, result))
+	}
+}
+
+func TestUpdateTimestamp(t *testing.T) {
+
+	w := &Doorman{LastChangeTimestamp: 10, Id: bson.ObjectIdHex(oid)}
+	m := &shared.DoormanUpdater{Timestamp: 9}
+	w.Update(m)
+	if w.LastChangeTimestamp != 10 {
+		t.Error()
+	}
+
+	m = &shared.DoormanUpdater{Timestamp: 11, Probabilities: []float64{}, Id: oid}
+	w.Update(m)
+	if w.LastChangeTimestamp != 11 {
+		t.Error()
+	}
+}
+
+func TestUpdateProbabilities(t *testing.T) {
+	w := &Doorman{LastChangeTimestamp: 0, Id: bson.ObjectIdHex(oid)}
+	m := &shared.DoormanUpdater{Timestamp: 0, Probabilities: []float64{0.5, 0.5}, Id: oid}
+	w.Update(m)
+	if len(w.Probabilities) != 0 {
+		t.Error()
+	}
+
+	m = &shared.DoormanUpdater{Timestamp: 2, Probabilities: []float64{0.5, 0.5}, Id: oid}
+	if err := w.Update(m); err != nil {
+		t.Error(err)
+	} else if !reflect.DeepEqual(w.Probabilities, []float64{0.5, 0.5}) {
+		t.Error("bad prob")
+	}
+
+	m = &shared.DoormanUpdater{Timestamp: 3, Probabilities: []float64{0.5, 0.25}, Id: oid}
+	if err := w.Update(m); err == nil {
+		t.Error("should received an error")
+	} else if !reflect.DeepEqual(w.Probabilities, []float64{0.5, 0.5}) {
+		t.Error("bad prob")
+	}
+
+}
+
+func randomBytes(n int) []byte {
+	b := make([]byte, n)
+	for i := range b {
+		b[i] = byte(i % 256)
+	}
+	return b
+}
+
+func TestUpdateHard(t *testing.T) {
+
+	wab := NewDoorman(bson.ObjectIdHex(oid), []float64{})
+	createMessage := func() string {
+		msg := &shared.DoormanUpdater{Timestamp: 2, Probabilities: []float64{0.5, 0.25, 0.25}, Id: oid}
+		if ret, err := json.Marshal(msg); err != nil {
+			panic(err)
+		} else {
+			return string(ret)
+		}
+	}
+	handler := func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/"+wab.Id.Hex() {
+			t.Error("bad url", r.URL)
+		}
+		fmt.Fprint(w, createMessage())
+	}
+
+	ts := httptest.NewServer(http.HandlerFunc(handler))
+	defer ts.Close()
+	if err := wab.UpdateHard(ts.URL); err != nil {
+		t.Error(err)
+	}
+	if wab.Length() != 3 {
+		t.Error()
+	}
+}
+
+func TestGetRandomCase(t *testing.T) {
+	wab := NewDoorman(bson.NewObjectId(), []float64{0.5, 0.5})
+	var ret uint = 0
+	for i := 0; i < 10000; i++ {
+		ret += wab.GetRandomCase()
+	}
+	if ret < 4900 || ret > 5100 {
+		t.Error("very improbable result of ", ret)
+	}
+}
+
+func BenchmarkGetCaseFromData(b *testing.B) {
+	var data = randomBytes(1024 * 1024)
+	w := NewDoorman(bson.NewObjectId(), []float64{0.1, 0.4, 0.4, 0.05, 0.05})
+	for i := 0; i < b.N; i++ {
+		w.GetCaseFromData(data)
+	}
+}