diff --git a/ants_test.go b/ants_test.go
index ff3cae5..bd04fe3 100644
--- a/ants_test.go
+++ b/ants_test.go
@@ -28,6 +28,8 @@ import (
 	"sync/atomic"
 	"testing"
 	"time"
+
+	"github.com/stretchr/testify/assert"
 )
 
 const (
@@ -238,9 +240,7 @@ func TestPanicHandler(t *testing.T) {
 		atomic.AddInt64(&panicCounter, 1)
 		t.Logf("catch panic with PanicHandler: %v", p)
 	}))
-	if err != nil {
-		t.Fatalf("create new pool failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create new pool failed: %v", err)
 	defer p0.Release()
 	wg.Add(1)
 	_ = p0.Submit(func() {
@@ -248,31 +248,20 @@ func TestPanicHandler(t *testing.T) {
 	})
 	wg.Wait()
 	c := atomic.LoadInt64(&panicCounter)
-	if c != 1 {
-		t.Errorf("panic handler didn't work, panicCounter: %d", c)
-	}
-	if p0.Running() != 0 {
-		t.Errorf("pool should be empty after panic")
-	}
-
+	assert.EqualValuesf(t, 1, c, "panic handler didn't work, panicCounter: %d", c)
+	assert.EqualValues(t, 0, p0.Running(), "pool should be empty after panic")
 	p1, err := NewPoolWithFunc(10, func(p interface{}) { panic(p) }, WithPanicHandler(func(p interface{}) {
 		defer wg.Done()
 		atomic.AddInt64(&panicCounter, 1)
 	}))
-	if err != nil {
-		t.Fatalf("create new pool with func failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create new pool with func failed: %v", err)
 	defer p1.Release()
 	wg.Add(1)
 	_ = p1.Invoke("Oops!")
 	wg.Wait()
 	c = atomic.LoadInt64(&panicCounter)
-	if c != 2 {
-		t.Errorf("panic handler didn't work, panicCounter: %d", c)
-	}
-	if p1.Running() != 0 {
-		t.Errorf("pool should be empty after panic")
-	}
+	assert.EqualValuesf(t, 2, c, "panic handler didn't work, panicCounter: %d", c)
+	assert.EqualValues(t, 0, p1.Running(), "pool should be empty after panic")
 }
 
 func TestPanicHandlerPreMalloc(t *testing.T) {
@@ -283,9 +272,7 @@ func TestPanicHandlerPreMalloc(t *testing.T) {
 		atomic.AddInt64(&panicCounter, 1)
 		t.Logf("catch panic with PanicHandler: %v", p)
 	}))
-	if err != nil {
-		t.Fatalf("create new pool failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create new pool failed: %v", err)
 	defer p0.Release()
 	wg.Add(1)
 	_ = p0.Submit(func() {
@@ -293,38 +280,25 @@ func TestPanicHandlerPreMalloc(t *testing.T) {
 	})
 	wg.Wait()
 	c := atomic.LoadInt64(&panicCounter)
-	if c != 1 {
-		t.Errorf("panic handler didn't work, panicCounter: %d", c)
-	}
-	if p0.Running() != 0 {
-		t.Errorf("pool should be empty after panic")
-	}
-
+	assert.EqualValuesf(t, 1, c, "panic handler didn't work, panicCounter: %d", c)
+	assert.EqualValues(t, 0, p0.Running(), "pool should be empty after panic")
 	p1, err := NewPoolWithFunc(10, func(p interface{}) { panic(p) }, WithPanicHandler(func(p interface{}) {
 		defer wg.Done()
 		atomic.AddInt64(&panicCounter, 1)
 	}))
-	if err != nil {
-		t.Fatalf("create new pool with func failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create new pool with func failed: %v", err)
 	defer p1.Release()
 	wg.Add(1)
 	_ = p1.Invoke("Oops!")
 	wg.Wait()
 	c = atomic.LoadInt64(&panicCounter)
-	if c != 2 {
-		t.Errorf("panic handler didn't work, panicCounter: %d", c)
-	}
-	if p1.Running() != 0 {
-		t.Errorf("pool should be empty after panic")
-	}
+	assert.EqualValuesf(t, 2, c, "panic handler didn't work, panicCounter: %d", c)
+	assert.EqualValues(t, 0, p1.Running(), "pool should be empty after panic")
 }
 
 func TestPoolPanicWithoutHandler(t *testing.T) {
 	p0, err := NewPool(10)
-	if err != nil {
-		t.Fatalf("create new pool failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create new pool failed: %v", err)
 	defer p0.Release()
 	_ = p0.Submit(func() {
 		panic("Oops!")
@@ -333,18 +307,14 @@ func TestPoolPanicWithoutHandler(t *testing.T) {
 	p1, err := NewPoolWithFunc(10, func(p interface{}) {
 		panic(p)
 	})
-	if err != nil {
-		t.Fatalf("create new pool with func failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create new pool with func failed: %v", err)
 	defer p1.Release()
 	_ = p1.Invoke("Oops!")
 }
 
 func TestPoolPanicWithoutHandlerPreMalloc(t *testing.T) {
 	p0, err := NewPool(10, WithPreAlloc(true))
-	if err != nil {
-		t.Fatalf("create new pool failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create new pool failed: %v", err)
 	defer p0.Release()
 	_ = p0.Submit(func() {
 		panic("Oops!")
@@ -353,70 +323,50 @@ func TestPoolPanicWithoutHandlerPreMalloc(t *testing.T) {
 	p1, err := NewPoolWithFunc(10, func(p interface{}) {
 		panic(p)
 	})
-	if err != nil {
-		t.Fatalf("create new pool with func failed: %s", err.Error())
-	}
+
+	assert.NoErrorf(t, err, "create new pool with func failed: %v", err)
+
 	defer p1.Release()
 	_ = p1.Invoke("Oops!")
 }
 
 func TestPurge(t *testing.T) {
 	p, err := NewPool(10)
-	if err != nil {
-		t.Fatalf("create TimingPool failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create TimingPool failed: %v", err)
 	defer p.Release()
 	_ = p.Submit(demoFunc)
 	time.Sleep(3 * DefaultCleanIntervalTime)
-	if p.Running() != 0 {
-		t.Error("all p should be purged")
-	}
+	assert.EqualValues(t, 0, p.Running(), "all p should be purged")
 	p1, err := NewPoolWithFunc(10, demoPoolFunc)
-	if err != nil {
-		t.Fatalf("create TimingPoolWithFunc failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create TimingPoolWithFunc failed: %v", err)
 	defer p1.Release()
 	_ = p1.Invoke(1)
 	time.Sleep(3 * DefaultCleanIntervalTime)
-	if p.Running() != 0 {
-		t.Error("all p should be purged")
-	}
+	assert.EqualValues(t, 0, p.Running(), "all p should be purged")
 }
 
 func TestPurgePreMalloc(t *testing.T) {
 	p, err := NewPool(10, WithPreAlloc(true))
-	if err != nil {
-		t.Fatalf("create TimingPool failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create TimingPool failed: %v", err)
 	defer p.Release()
 	_ = p.Submit(demoFunc)
 	time.Sleep(3 * DefaultCleanIntervalTime)
-	if p.Running() != 0 {
-		t.Error("all p should be purged")
-	}
+	assert.EqualValues(t, 0, p.Running(), "all p should be purged")
 	p1, err := NewPoolWithFunc(10, demoPoolFunc)
-	if err != nil {
-		t.Fatalf("create TimingPoolWithFunc failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create TimingPoolWithFunc failed: %v", err)
 	defer p1.Release()
 	_ = p1.Invoke(1)
 	time.Sleep(3 * DefaultCleanIntervalTime)
-	if p.Running() != 0 {
-		t.Error("all p should be purged")
-	}
+	assert.EqualValues(t, 0, p.Running(), "all p should be purged")
 }
 
 func TestNonblockingSubmit(t *testing.T) {
 	poolSize := 10
 	p, err := NewPool(poolSize, WithNonblocking(true))
-	if err != nil {
-		t.Fatalf("create TimingPool failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create TimingPool failed: %v", err)
 	defer p.Release()
 	for i := 0; i < poolSize-1; i++ {
-		if err := p.Submit(longRunningFunc); err != nil {
-			t.Fatalf("nonblocking submit when pool is not full shouldn't return error")
-		}
+		assert.NoError(t, p.Submit(longRunningFunc), "nonblocking submit when pool is not full shouldn't return error")
 	}
 	ch := make(chan struct{})
 	ch1 := make(chan struct{})
@@ -425,40 +375,28 @@ func TestNonblockingSubmit(t *testing.T) {
 		close(ch1)
 	}
 	// p is full now.
-	if err := p.Submit(f); err != nil {
-		t.Fatalf("nonblocking submit when pool is not full shouldn't return error")
-	}
-	if err := p.Submit(demoFunc); err == nil || err != ErrPoolOverload {
-		t.Fatalf("nonblocking submit when pool is full should get an ErrPoolOverload")
-	}
+	assert.NoError(t, p.Submit(f), "nonblocking submit when pool is not full shouldn't return error")
+	assert.EqualError(t, p.Submit(demoFunc), ErrPoolOverload.Error(), "nonblocking submit when pool is full should get an ErrPoolOverload")
 	// interrupt f to get an available worker
 	close(ch)
 	<-ch1
-	if err := p.Submit(demoFunc); err != nil {
-		t.Fatalf("nonblocking submit when pool is not full shouldn't return error")
-	}
+	assert.NoError(t, p.Submit(demoFunc), "nonblocking submit when pool is not full shouldn't return error")
 }
 
 func TestMaxBlockingSubmit(t *testing.T) {
 	poolSize := 10
 	p, err := NewPool(poolSize, WithMaxBlockingTasks(1))
-	if err != nil {
-		t.Fatalf("create TimingPool failed: %s", err.Error())
-	}
+	assert.NoErrorf(t, err, "create TimingPool failed: %v", err)
 	defer p.Release()
 	for i := 0; i < poolSize-1; i++ {
-		if err := p.Submit(longRunningFunc); err != nil {
-			t.Fatalf("submit when pool is not full shouldn't return error")
-		}
+		assert.NoError(t, p.Submit(longRunningFunc), "submit when pool is not full shouldn't return error")
 	}
 	ch := make(chan struct{})
 	f := func() {
 		<-ch
 	}
 	// p is full now.
-	if err := p.Submit(f); err != nil {
-		t.Fatalf("submit when pool is not full shouldn't return error")
-	}
+	assert.NoError(t, p.Submit(f), "submit when pool is not full shouldn't return error")
 	var wg sync.WaitGroup
 	wg.Add(1)
 	errCh := make(chan error, 1)
@@ -471,9 +409,7 @@ func TestMaxBlockingSubmit(t *testing.T) {
 	}()
 	time.Sleep(1 * time.Second)
 	// already reached max blocking limit
-	if err := p.Submit(demoFunc); err != ErrPoolOverload {
-		t.Fatalf("blocking submit when pool reach max blocking submit should return ErrPoolOverload")
-	}
+	assert.EqualError(t, p.Submit(demoFunc), ErrPoolOverload.Error(), "blocking submit when pool reach max blocking submit should return ErrPoolOverload")
 	// interrupt f to make blocking submit successful.
 	close(ch)
 	wg.Wait()
@@ -491,48 +427,32 @@ func TestNonblockingSubmitWithFunc(t *testing.T) {
 		longRunningPoolFunc(i)
 		close(ch1)
 	}, WithNonblocking(true))
-	if err != nil {
-		t.Fatalf("create TimingPool failed: %s", err.Error())
-	}
+	assert.NoError(t, err, "create TimingPool failed: %v", err)
 	defer p.Release()
 	for i := 0; i < poolSize-1; i++ {
-		if err := p.Invoke(nil); err != nil {
-			t.Fatalf("nonblocking submit when pool is not full shouldn't return error")
-		}
+		assert.NoError(t, p.Invoke(nil), "nonblocking submit when pool is not full shouldn't return error")
 	}
 	ch := make(chan struct{})
 	// p is full now.
-	if err := p.Invoke(ch); err != nil {
-		t.Fatalf("nonblocking submit when pool is not full shouldn't return error")
-	}
-	if err := p.Invoke(nil); err == nil || err != ErrPoolOverload {
-		t.Fatalf("nonblocking submit when pool is full should get an ErrPoolOverload")
-	}
+	assert.NoError(t, p.Invoke(ch), "nonblocking submit when pool is not full shouldn't return error")
+	assert.EqualError(t, p.Invoke(nil), ErrPoolOverload.Error(), "nonblocking submit when pool is full should get an ErrPoolOverload")
 	// interrupt f to get an available worker
 	close(ch)
 	<-ch1
-	if err := p.Invoke(nil); err != nil {
-		t.Fatalf("nonblocking submit when pool is not full shouldn't return error")
-	}
+	assert.NoError(t, p.Invoke(nil), "nonblocking submit when pool is not full shouldn't return error")
 }
 
 func TestMaxBlockingSubmitWithFunc(t *testing.T) {
 	poolSize := 10
 	p, err := NewPoolWithFunc(poolSize, longRunningPoolFunc, WithMaxBlockingTasks(1))
-	if err != nil {
-		t.Fatalf("create TimingPool failed: %s", err.Error())
-	}
+	assert.NoError(t, err, "create TimingPool failed: %v", err)
 	defer p.Release()
 	for i := 0; i < poolSize-1; i++ {
-		if err := p.Invoke(Param); err != nil {
-			t.Fatalf("submit when pool is not full shouldn't return error")
-		}
+		assert.NoError(t, p.Invoke(Param), "submit when pool is not full shouldn't return error")
 	}
 	ch := make(chan struct{})
 	// p is full now.
-	if err := p.Invoke(ch); err != nil {
-		t.Fatalf("submit when pool is not full shouldn't return error")
-	}
+	assert.NoError(t, p.Invoke(ch), "submit when pool is not full shouldn't return error")
 	var wg sync.WaitGroup
 	wg.Add(1)
 	errCh := make(chan error, 1)
@@ -545,9 +465,7 @@ func TestMaxBlockingSubmitWithFunc(t *testing.T) {
 	}()
 	time.Sleep(1 * time.Second)
 	// already reached max blocking limit
-	if err := p.Invoke(Param); err != ErrPoolOverload {
-		t.Fatalf("blocking submit when pool reach max blocking submit should return ErrPoolOverload: %v", err)
-	}
+	assert.EqualErrorf(t, p.Invoke(Param), ErrPoolOverload.Error(), "blocking submit when pool reach max blocking submit should return ErrPoolOverload: %v", err)
 	// interrupt one func to make blocking submit successful.
 	close(ch)
 	wg.Wait()
diff --git a/go.mod b/go.mod
index 8376767..cfc7218 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,9 @@
 module github.com/panjf2000/ants/v2
 
 go 1.13
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/stretchr/testify v1.4.0
+	gopkg.in/yaml.v2 v2.2.7 // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..c435420
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,16 @@
+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/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+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/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/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=
+gopkg.in/yaml.v2 v2.2.7 h1:VUgggvou5XRW9mHwD/yXxIYSMtY0zoKQf/v226p2nyo=
+gopkg.in/yaml.v2 v2.2.7/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/worker_loop_queue_test.go b/worker_loop_queue_test.go
index 573bff8..b045c6c 100644
--- a/worker_loop_queue_test.go
+++ b/worker_loop_queue_test.go
@@ -3,22 +3,16 @@ package ants
 import (
 	"testing"
 	"time"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestNewLoopQueue(t *testing.T) {
 	size := 100
 	q := newWorkerLoopQueue(size)
-	if q.len() != 0 {
-		t.Fatalf("Len error")
-	}
-
-	if !q.isEmpty() {
-		t.Fatalf("IsEmpty error")
-	}
-
-	if q.detach() != nil {
-		t.Fatalf("Dequeue error")
-	}
+	assert.EqualValues(t, 0, q.len(), "Len error")
+	assert.Equal(t, true, q.isEmpty(), "IsEmpty error")
+	assert.Nil(t, q.detach(), "Dequeue error")
 }
 
 func TestLoopQueue(t *testing.T) {
@@ -31,17 +25,10 @@ func TestLoopQueue(t *testing.T) {
 			break
 		}
 	}
-
-	if q.len() != 5 {
-		t.Fatalf("Len error")
-	}
-
+	assert.EqualValues(t, 5, q.len(), "Len error")
 	v := q.detach()
 	t.Log(v)
-
-	if q.len() != 4 {
-		t.Fatalf("Len error")
-	}
+	assert.EqualValues(t, 4, q.len(), "Len error")
 
 	time.Sleep(time.Second)
 
@@ -51,19 +38,11 @@ func TestLoopQueue(t *testing.T) {
 			break
 		}
 	}
-
-	if q.len() != 10 {
-		t.Fatalf("Len error")
-	}
+	assert.EqualValues(t, 10, q.len(), "Len error")
 
 	err := q.insert(&goWorker{recycleTime: time.Now()})
-	if err == nil {
-		t.Fatalf("Enqueue error")
-	}
+	assert.Error(t, err, "Enqueue, error")
 
 	q.retrieveExpiry(time.Second)
-
-	if q.len() != 6 {
-		t.Fatalf("Len error: %d", q.len())
-	}
+	assert.EqualValuesf(t, 6, q.len(), "Len error: %d", q.len())
 }
diff --git a/worker_stack_test.go b/worker_stack_test.go
index 93d04f5..2c33e08 100644
--- a/worker_stack_test.go
+++ b/worker_stack_test.go
@@ -5,22 +5,16 @@ package ants
 import (
 	"testing"
 	"time"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestNewWorkerStack(t *testing.T) {
 	size := 100
 	q := newWorkerStack(size)
-	if q.len() != 0 {
-		t.Fatal("Len error")
-	}
-
-	if !q.isEmpty() {
-		t.Fatal("IsEmpty error")
-	}
-
-	if q.detach() != nil {
-		t.Fatal("Dequeue error")
-	}
+	assert.EqualValues(t, 0, q.len(), "Len error")
+	assert.Equal(t, true, q.isEmpty(), "IsEmpty error")
+	assert.Nil(t, q.detach(), "Dequeue error")
 }
 
 func TestWorkerStack(t *testing.T) {
@@ -32,9 +26,7 @@ func TestWorkerStack(t *testing.T) {
 			break
 		}
 	}
-	if q.len() != 5 {
-		t.Fatal("Len error")
-	}
+	assert.EqualValues(t, 5, q.len(), "Len error")
 
 	expired := time.Now()
 
@@ -51,16 +43,9 @@ func TestWorkerStack(t *testing.T) {
 			t.Fatal("Enqueue error")
 		}
 	}
-
-	if q.len() != 12 {
-		t.Fatal("Len error")
-	}
-
+	assert.EqualValues(t, 12, q.len(), "Len error")
 	q.retrieveExpiry(time.Second)
-
-	if q.len() != 6 {
-		t.Fatal("Len error")
-	}
+	assert.EqualValues(t, 6, q.len(), "Len error")
 }
 
 // It seems that something wrong with time.Now() on Windows, not sure whether it is a bug on Windows, so exclude this test
@@ -73,34 +58,18 @@ func TestSearch(t *testing.T) {
 
 	_ = q.insert(&goWorker{recycleTime: time.Now()})
 
-	index := q.binarySearch(0, q.len()-1, time.Now())
-	if index != 0 {
-		t.Fatal("index should be 0")
-	}
-
-	index = q.binarySearch(0, q.len()-1, expiry1)
-	if index != -1 {
-		t.Fatal("index should be -1")
-	}
+	assert.EqualValues(t, 0, q.binarySearch(0, q.len()-1, time.Now()), "index should be 0")
+	assert.EqualValues(t, -1, q.binarySearch(0, q.len()-1, expiry1), "index should be -1")
 
 	// 2
 	expiry2 := time.Now()
 	_ = q.insert(&goWorker{recycleTime: time.Now()})
 
-	index = q.binarySearch(0, q.len()-1, expiry1)
-	if index != -1 {
-		t.Fatal("index should be -1")
-	}
+	assert.EqualValues(t, -1, q.binarySearch(0, q.len()-1, expiry1), "index should be -1")
 
-	index = q.binarySearch(0, q.len()-1, expiry2)
-	if index != 0 {
-		t.Fatal("index should be 0")
-	}
+	assert.EqualValues(t, 0, q.binarySearch(0, q.len()-1, expiry2), "index should be 0")
 
-	index = q.binarySearch(0, q.len()-1, time.Now())
-	if index != 1 {
-		t.Fatal("index should be 1")
-	}
+	assert.EqualValues(t, 1, q.binarySearch(0, q.len()-1, time.Now()), "index should be 1")
 
 	// more
 	for i := 0; i < 5; i++ {
@@ -115,8 +84,5 @@ func TestSearch(t *testing.T) {
 		_ = q.insert(&goWorker{recycleTime: time.Now()})
 	}
 
-	index = q.binarySearch(0, q.len()-1, expiry3)
-	if index != 7 {
-		t.Fatal("index should be 7")
-	}
+	assert.EqualValues(t, 7, q.binarySearch(0, q.len()-1, expiry3), "index should be 7")
 }