added tests for conn mock

testing/conn_mock.go

@@ -27,6 +27,6 @@ func (m *MockConn) Read(b []byte) (n int, err error) {
 		count = len(m.Bytes)
 	}
 
-	copy(m.Bytes[0:count], b)
+	copy(b, m.Bytes[0:count])
 	return count, nil
 }

testing/conn_mock_test.go

+package testing
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestWrite(t *testing.T) {
+	m := &MockConn{}
+
+	payload := []byte{1, 2, 3}
+	m.Write(payload)
+
+	assert.Equal(t, payload, m.Bytes)
+}
+
+func TestRead(t *testing.T) {
+	m := &MockConn{}
+
+	payload := []byte{1, 2, 3}
+	m.Bytes = payload
+
+	buffer := make([]byte, 4)
+	m.Read(buffer)
+
+	assert.Equal(t, payload, buffer[:3])
+}