Fix unit test by eliminating treading issue

Author: brutella

test_readwritecloser.go

@@ -2,17 +2,41 @@ package can
 
 import (
 	"bytes"
+	"io"
+	"time"
 )
 
 type echoReadWriteCloser struct {
-	buf bytes.Buffer
+	buf    bytes.Buffer
+	closed bool
 }
 
 // NewEchoReadWriteCloser returns a ReadWriteCloser which echoes received bytes.
 func NewEchoReadWriteCloser() ReadWriteCloser {
 	return NewReadWriteCloser(&echoReadWriteCloser{})
 }
 
-func (rw *echoReadWriteCloser) Read(b []byte) (n int, err error)  { return rw.buf.Read(b) }
-func (rw *echoReadWriteCloser) Write(b []byte) (n int, err error) { return rw.buf.Write(b) }
-func (rw *echoReadWriteCloser) Close() error                      { return nil }
+func (rw *echoReadWriteCloser) Read(b []byte) (n int, err error) {
+	for {
+		if rw.buf.Len() > 0 {
+			return rw.buf.Read(b)
+		}
+
+		if rw.closed == true {
+			break
+		}
+
+		<-time.After(time.Millisecond * 1)
+	}
+
+	return 0, io.EOF
+}
+
+func (rw *echoReadWriteCloser) Write(b []byte) (n int, err error) {
+	return rw.buf.Write(b)
+}
+
+func (rw *echoReadWriteCloser) Close() error {
+	rw.closed = true
+	return nil
+}