diff --git a/.travis.yml b/.travis.yml
index b39eb17..9352cec 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,7 +2,6 @@ language: go
 sudo: required
 
 go:
-  - "1.11"
   - "1.12"
   - master
 
diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 0000000..f06b593
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+  "go.formatTool": "goimports"
+}
\ No newline at end of file
diff --git a/go.mod b/go.mod
index ad3134d..91de102 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,8 @@
 module github.com/vicanso/cod-tracker
 
-require github.com/vicanso/cod v0.0.7
+go 1.12
+
+require (
+	github.com/stretchr/testify v1.3.0
+	github.com/vicanso/cod v0.1.1
+)
diff --git a/go.sum b/go.sum
index a0c2e2b..4bc57c8 100644
--- a/go.sum
+++ b/go.sum
@@ -7,8 +7,8 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
-github.com/vicanso/cod v0.0.7 h1:CHyIL7zkNOhEv0JosDDyRHCUALovry1P+dLISaANj1w=
-github.com/vicanso/cod v0.0.7/go.mod h1:tHGTs/JDTcp/OE4VaCutVMpYL69aR1rKUggsHviTuFc=
+github.com/vicanso/cod v0.1.1 h1:l4dbZSGhGRVnrxLbArC/60GXNxDo0O/RlY5z4iHSa7I=
+github.com/vicanso/cod v0.1.1/go.mod h1:T5GOazXuYrwwE1qMA0G3zka7NVwwkoL2fYIWNfeEpJw=
 github.com/vicanso/hes v0.1.4 h1:n8kG8krvNJF4Sj1PvZOEUzdUsmDSbCcGr8C1nYnoP+o=
 github.com/vicanso/hes v0.1.4/go.mod h1:bG0UJ3EihDKObFcLLwJYjxHHr9saFllsFcepyDIvFlo=
 github.com/vicanso/keygrip v0.1.0 h1:/zYzoVIbREAvaxSM7bo3/oSXuuYztaP71dPBfhRoNkM=
diff --git a/tracker.go b/tracker.go
index d48b93b..42960cc 100644
--- a/tracker.go
+++ b/tracker.go
@@ -16,6 +16,7 @@ package tracker
 
 import (
 	"encoding/json"
+	"errors"
 	"regexp"
 
 	"github.com/vicanso/cod"
@@ -29,7 +30,8 @@ const (
 )
 
 var (
-	defaultMaskFields = regexp.MustCompile(`password`)
+	defaultMaskFields  = regexp.MustCompile(`password`)
+	errNoTrackFunction = errors.New("require on track function")
 )
 
 type (
@@ -74,7 +76,7 @@ func New(config Config) cod.Handler {
 		mask = defaultMaskFields
 	}
 	if config.OnTrack == nil {
-		panic("require on track function")
+		panic(errNoTrackFunction)
 	}
 	skipper := config.Skipper
 	if skipper == nil {
diff --git a/tracker_test.go b/tracker_test.go
index c5ae8db..077ce3f 100644
--- a/tracker_test.go
+++ b/tracker_test.go
@@ -2,23 +2,51 @@ package tracker
 
 import (
 	"errors"
+	"fmt"
 	"net/http/httptest"
+	"os"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
 	"github.com/vicanso/cod"
 )
 
+func TestNoTrackPanic(t *testing.T) {
+	assert := assert.New(t)
+	done := false
+	defer func() {
+		r := recover()
+		assert.Equal(r.(error), errNoTrackFunction)
+		done = true
+	}()
+
+	New(Config{})
+	assert.True(done)
+}
+
+func TestConverMap(t *testing.T) {
+	assert := assert.New(t)
+	assert.Nil(convertMap(nil, nil))
+	assert.Equal(convertMap(map[string]string{
+		"password": "123",
+		"foo":      "bar",
+	}, defaultMaskFields), map[string]string{
+		"foo":      "bar",
+		"password": "***",
+	})
+}
+
 func TestTracker(t *testing.T) {
+	assert := assert.New(t)
+	customErr := errors.New("abcd")
 	done := false
 	fn := New(Config{
 		OnTrack: func(info *Info, _ *cod.Context) {
-			if info.Result != HandleFail ||
-				info.Query["type"] != "1" ||
-				info.Query["passwordType"] != "***" ||
-				info.Params["category"] != "login" ||
-				info.Form["password"] != "***" {
-				t.Fatalf("tracker info is invalid")
-			}
+			assert.Equal(info.Result, HandleFail)
+			assert.Equal(info.Query["type"], "1")
+			assert.Equal(info.Query["passwordType"], "***")
+			assert.Equal(info.Params["category"], "login")
+			assert.Equal(info.Form["password"], "***")
 			done = true
 		},
 	})
@@ -32,10 +60,26 @@ func TestTracker(t *testing.T) {
 		"category": "login",
 	}
 	c.Next = func() error {
-		return errors.New("abcd")
+		return customErr
 	}
-	fn(c)
-	if !done {
-		t.Fatalf("tracker middleware fail")
+	err := fn(c)
+	assert.Equal(err, customErr)
+	assert.True(done, "tracker middleware fail")
+}
+
+// https://stackoverflow.com/questions/50120427/fail-unit-tests-if-coverage-is-below-certain-percentage
+func TestMain(m *testing.M) {
+	// call flag.Parse() here if TestMain uses flags
+	rc := m.Run()
+
+	// rc 0 means we've passed,
+	// and CoverMode will be non empty if run with -cover
+	if rc == 0 && testing.CoverMode() != "" {
+		c := testing.Coverage()
+		if c < 0.9 {
+			fmt.Println("Tests passed but coverage failed at", c)
+			rc = -1
+		}
 	}
+	os.Exit(rc)
 }