move some io related utils to pkg/ioutils

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)

ioutils/readers_test.go

@@ -0,0 +1,34 @@
+package ioutils
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+	"testing"
+)
+
+func TestBufReader(t *testing.T) {
+	reader, writer := io.Pipe()
+	bufreader := NewBufReader(reader)
+
+	// Write everything down to a Pipe
+	// Usually, a pipe should block but because of the buffered reader,
+	// the writes will go through
+	done := make(chan bool)
+	go func() {
+		writer.Write([]byte("hello world"))
+		writer.Close()
+		done <- true
+	}()
+
+	// Drain the reader *after* everything has been written, just to verify
+	// it is indeed buffering
+	<-done
+	output, err := ioutil.ReadAll(bufreader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(output, []byte("hello world")) {
+		t.Error(string(output))
+	}
+}