diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index 2cc106ce0..d46599eed 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -63,10 +63,15 @@ jobs:
       run: go build -v ./cmd/bbgo
 
     - name: Test
-      run: go test ./pkg/...
+      run: go test -race -coverprofile coverage.txt -covermode atomic ./pkg/...
 
     - name: TestDnum
-      run: go test -tags dnum ./pkg/...
+      run: go test -race -coverprofile coverage_dnum.txt -covermode atomic -tags dnum ./pkg/...
+
+    - name: Upload Coverage Report
+      uses: codecov/codecov-action@v3
+      with:
+        files: ./coverage.txt,./coverage_dnum.txt
 
     - name: Create dotenv file
       run: |
diff --git a/.gitignore b/.gitignore
index 1b3b385e6..543fe0cdc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -44,3 +44,6 @@ otp*png
 
 *.swp
 /pkg/backtest/assets.go
+
+coverage.txt
+coverage_dum.txt
diff --git a/codecov.yml b/codecov.yml
new file mode 100644
index 000000000..c4a76f25a
--- /dev/null
+++ b/codecov.yml
@@ -0,0 +1,23 @@
+codecov:
+    require_ci_to_pass: true
+
+comment:
+    behavior: default
+    layout: "reach,diff,flags,files,footer"
+    require_changes: no
+
+parsers:
+    gcov:
+        branch_detection:
+            conditional: yes
+            loop: yes
+            method: no
+            macro: no
+
+coverage:
+    precision: 2
+    round: down
+    range: "70...100"
+
+github_checks:
+    annotations: false
diff --git a/pkg/depth/buffer.go b/pkg/depth/buffer.go
index 26e74edf7..620743639 100644
--- a/pkg/depth/buffer.go
+++ b/pkg/depth/buffer.go
@@ -133,6 +133,8 @@ func (b *Buffer) AddUpdate(o types.SliceOrderBook, firstUpdateID int64, finalArg
 }
 
 func (b *Buffer) fetchAndPush() error {
+	b.mu.Lock()
+	defer b.mu.Unlock()
 	book, finalUpdateID, err := b.fetcher()
 	if err != nil {
 		return err
@@ -140,9 +142,6 @@ func (b *Buffer) fetchAndPush() error {
 
 	log.Debugf("fetched depth snapshot, final update id %d", finalUpdateID)
 
-	b.mu.Lock()
-	defer b.mu.Unlock()
-
 	if len(b.buffer) > 0 {
 		// the snapshot is too early
 		if finalUpdateID < b.buffer[0].FirstUpdateID {
diff --git a/pkg/depth/buffer_test.go b/pkg/depth/buffer_test.go
index 89f75d68b..9c33effdd 100644
--- a/pkg/depth/buffer_test.go
+++ b/pkg/depth/buffer_test.go
@@ -23,6 +23,7 @@ func TestDepthBuffer_ReadyState(t *testing.T) {
 			},
 		}, 33, nil
 	})
+	buf.SetBufferingPeriod(time.Millisecond * 5)
 
 	readyC := make(chan struct{})
 	buf.OnReady(func(snapshot types.SliceOrderBook, updates []Update) {
diff --git a/pkg/util/reonce_test.go b/pkg/util/reonce_test.go
index 7a18fc437..bd3528481 100644
--- a/pkg/util/reonce_test.go
+++ b/pkg/util/reonce_test.go
@@ -1,6 +1,7 @@
 package util
 
 import (
+	"sync"
 	"testing"
 	"time"
 
@@ -10,14 +11,19 @@ import (
 func TestReonce_DoAndReset(t *testing.T) {
 	var cnt = 0
 	var reonce Reonce
+	var wgAll, wg sync.WaitGroup
+	wg.Add(1)
+	wgAll.Add(2)
 	go reonce.Do(func() {
 		t.Log("once #1")
 		time.Sleep(10 * time.Millisecond)
 		cnt++
+		wg.Done()
+		wgAll.Done()
 	})
 
 	// make sure it's locked
-	time.Sleep(10 * time.Millisecond)
+	wg.Wait()
 	t.Logf("reset")
 	reonce.Reset()
 
@@ -25,8 +31,9 @@ func TestReonce_DoAndReset(t *testing.T) {
 		t.Log("once #2")
 		time.Sleep(10 * time.Millisecond)
 		cnt++
+		wgAll.Done()
 	})
 
-	time.Sleep(time.Second)
+	wgAll.Wait()
 	assert.Equal(t, 2, cnt)
 }