#1: add initial tests for queue, upgrade github.com/stretchr/testify

Gopkg.toml

@@ -33,7 +33,7 @@ ignored = ["github.com/elyby/chrly"]
 
 [[constraint]]
   name = "github.com/stretchr/testify"
-  version = "^1.1.4"
+  version = "^1.3.0"
 
 [[constraint]]
   name = "github.com/golang/mock"

api/mojang/queue/queue.go

@@ -10,6 +10,7 @@ import (
 
 var usernamesToUuids = mojang.UsernamesToUuids
 var uuidToTextures = mojang.UuidToTextures
+var delay = time.Second
 
 type JobsQueue struct {
 	Storage Storage
@@ -18,24 +19,26 @@ type JobsQueue struct {
 	queue       jobsQueue
 }
 
-func (ctx *JobsQueue) GetTexturesForUsername(username string) (resultChan chan *mojang.SignedTexturesResponse) {
+func (ctx *JobsQueue) GetTexturesForUsername(username string) *mojang.SignedTexturesResponse {
 	ctx.onFirstCall.Do(func() {
 		ctx.queue.New()
 		ctx.startQueue()
 	})
 
+	resultChan := make(chan *mojang.SignedTexturesResponse)
 	// TODO: prevent of adding the same username more than once
 	ctx.queue.Enqueue(&jobItem{username, resultChan})
 
-	return
+	return <-resultChan
 }
 
 func (ctx *JobsQueue) startQueue() {
 	go func() {
-		for {
+		time.Sleep(delay)
+		for true {
 			start := time.Now()
 			ctx.queueRound()
-			time.Sleep(time.Second - time.Since(start))
+			time.Sleep(delay - time.Since(start))
 		}
 	}()
 }
@@ -66,7 +69,7 @@ func (ctx *JobsQueue) queueRound() {
 	var wg sync.WaitGroup
 	for _, job := range jobs {
 		wg.Add(1)
-		go func() {
+		go func(job *jobItem) {
 			var result *mojang.SignedTexturesResponse
 			shouldCache := true
 			var uuid string
@@ -95,7 +98,7 @@ func (ctx *JobsQueue) queueRound() {
 			if shouldCache {
 				// TODO: store result to cache
 			}
-		}()
+		}(job)
 	}
 
 	wg.Wait()

api/mojang/queue/queue_test.go

@@ -0,0 +1,215 @@
+package queue
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"errors"
+	"log"
+	"testing"
+	"time"
+
+	"github.com/elyby/chrly/api/mojang"
+	testify "github.com/stretchr/testify/assert"
+)
+
+func TestJobsQueue_GetTexturesForUsername(t *testing.T) {
+	delay = 50 * time.Millisecond
+
+	t.Run("receive textures for one username", func(t *testing.T) {
+		assert := testify.New(t)
+
+		usernamesToUuids = createUsernameToUuidsMock(
+			assert,
+			[]string{"maksimkurb"},
+			[]*mojang.ProfileInfo{
+				{Id: "0d252b7218b648bfb86c2ae476954d32", Name: "maksimkurb"},
+			},
+			nil,
+		)
+		uuidToTextures = createUuidToTextures([]*createUuidToTexturesResult{
+			createTexturesResult("0d252b7218b648bfb86c2ae476954d32", "maksimkurb"),
+		})
+
+		queue := &JobsQueue{Storage: &NilStorage{}}
+		result := queue.GetTexturesForUsername("maksimkurb")
+
+		if assert.NotNil(result) {
+			assert.Equal("0d252b7218b648bfb86c2ae476954d32", result.Id)
+			assert.Equal("maksimkurb", result.Name)
+		}
+	})
+
+	t.Run("receive textures for few usernames", func(t *testing.T) {
+		assert := testify.New(t)
+
+		usernamesToUuids = createUsernameToUuidsMock(
+			assert,
+			[]string{"maksimkurb", "Thinkofdeath"},
+			[]*mojang.ProfileInfo{
+				{Id: "0d252b7218b648bfb86c2ae476954d32", Name: "maksimkurb"},
+				{Id: "4566e69fc90748ee8d71d7ba5aa00d20", Name: "Thinkofdeath"},
+			},
+			nil,
+		)
+		uuidToTextures = createUuidToTextures([]*createUuidToTexturesResult{
+			createTexturesResult("0d252b7218b648bfb86c2ae476954d32", "maksimkurb"),
+			createTexturesResult("4566e69fc90748ee8d71d7ba5aa00d20", "Thinkofdeath"),
+		})
+
+		queue := &JobsQueue{Storage: &NilStorage{}}
+		resultChan1 := make(chan *mojang.SignedTexturesResponse)
+		resultChan2 := make(chan *mojang.SignedTexturesResponse)
+		go func() {
+			resultChan1 <- queue.GetTexturesForUsername("maksimkurb")
+		}()
+		go func() {
+			resultChan2 <- queue.GetTexturesForUsername("Thinkofdeath")
+		}()
+
+		assert.NotNil(<-resultChan1)
+		assert.NotNil(<-resultChan2)
+	})
+
+	t.Run("query no more than 100 usernames and all left on the next iteration", func(t *testing.T) {
+		assert := testify.New(t)
+
+		usernames := make([]string, 120, 120)
+		for i := 0; i < 120; i++ {
+			usernames[i] = randStr(8)
+		}
+
+		usernamesToUuids = createUsernameToUuidsMock(assert, usernames[0:100], []*mojang.ProfileInfo{}, nil)
+
+		queue := &JobsQueue{Storage: &NilStorage{}}
+
+		scheduleUsername := func(username string) {
+			queue.GetTexturesForUsername(username)
+		}
+
+		for _, username := range usernames {
+			go scheduleUsername(username)
+			time.Sleep(50 * time.Microsecond) // Add delay to have consistent order
+		}
+
+		// Let it begin first iteration
+		time.Sleep(delay + delay/2)
+
+		usernamesToUuids = createUsernameToUuidsMock(
+			assert,
+			usernames[100:120],
+			[]*mojang.ProfileInfo{},
+			nil,
+		)
+
+		time.Sleep(delay)
+	})
+
+	t.Run("should do nothing if queue is empty", func(t *testing.T) {
+		assert := testify.New(t)
+
+		usernamesToUuids = createUsernameToUuidsMock(assert, []string{"maksimkurb"}, []*mojang.ProfileInfo{}, nil)
+		uuidToTextures = func(uuid string, signed bool) (*mojang.SignedTexturesResponse, error) {
+			t.Error("this method shouldn't be called")
+			return nil, nil
+		}
+
+		// Perform first iteration and await it finish
+		queue := &JobsQueue{Storage: &NilStorage{}}
+		result := queue.GetTexturesForUsername("maksimkurb")
+		assert.Nil(result)
+
+		// Override external API call that indicates, that queue is still trying to obtain somethid
+		usernamesToUuids = func(usernames []string) ([]*mojang.ProfileInfo, error) {
+			t.Error("this method shouldn't be called")
+			return nil, nil
+		}
+
+		// Let it to iterate few times
+		time.Sleep(delay * 2)
+	})
+
+	t.Run("handle 429 error when exchanging usernames to uuids", func(t *testing.T) {
+		assert := testify.New(t)
+
+		usernamesToUuids = createUsernameToUuidsMock(assert, []string{"maksimkurb"}, nil, &mojang.TooManyRequestsError{})
+
+		queue := &JobsQueue{Storage: &NilStorage{}}
+		result := queue.GetTexturesForUsername("maksimkurb")
+		assert.Nil(result)
+	})
+
+	t.Run("handle 429 error when requesting user's textures", func(t *testing.T) {
+		assert := testify.New(t)
+
+		usernamesToUuids = createUsernameToUuidsMock(
+			assert,
+			[]string{"maksimkurb"},
+			[]*mojang.ProfileInfo{
+				{Id: "0d252b7218b648bfb86c2ae476954d32", Name: "maksimkurb"},
+			},
+			nil,
+		)
+		uuidToTextures = createUuidToTextures([]*createUuidToTexturesResult{
+			createTexturesResult("0d252b7218b648bfb86c2ae476954d32", &mojang.TooManyRequestsError{}),
+		})
+
+		queue := &JobsQueue{Storage: &NilStorage{}}
+		result := queue.GetTexturesForUsername("maksimkurb")
+		assert.Nil(result)
+	})
+}
+
+func createUsernameToUuidsMock(
+	assert *testify.Assertions,
+	expectedUsernames []string,
+	result []*mojang.ProfileInfo,
+	err error,
+) func(usernames []string) ([]*mojang.ProfileInfo, error) {
+	return func(usernames []string) ([]*mojang.ProfileInfo, error) {
+		assert.ElementsMatch(expectedUsernames, usernames)
+		return result, err
+	}
+}
+
+type createUuidToTexturesResult struct {
+	uuid   string
+	result *mojang.SignedTexturesResponse
+	err    error
+}
+
+func createTexturesResult(uuid string, result interface{}) *createUuidToTexturesResult {
+	output := &createUuidToTexturesResult{uuid: uuid}
+	if username, ok := result.(string); ok {
+		output.result = &mojang.SignedTexturesResponse{Id: uuid, Name: username}
+	} else if err, ok := result.(error); ok {
+		output.err = err
+	} else {
+		log.Fatal("invalid result type passed")
+	}
+
+	return output
+}
+
+func createUuidToTextures(
+	results []*createUuidToTexturesResult,
+) func(uuid string, signed bool) (*mojang.SignedTexturesResponse, error) {
+	return func(uuid string, signed bool) (*mojang.SignedTexturesResponse, error) {
+		for _, result := range results {
+			if result.uuid == uuid {
+				return result.result, result.err
+			}
+		}
+
+		return nil, errors.New("cannot find corresponding result")
+	}
+}
+
+// https://stackoverflow.com/a/50581165
+func randStr(len int) string {
+	buff := make([]byte, len)
+	rand.Read(buff)
+	str := base64.StdEncoding.EncodeToString(buff)
+
+	// Base 64 can be longer than len
+	return str[:len]
+}