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package helper
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"testing"
"testing/iotest"
)
func TestBusyReader(t *testing.T) {
testData := "test data"
r := testReader(testData)
br, _ := NewWriteAfterReader(r, &bytes.Buffer{})
result, err := ioutil.ReadAll(br)
if err != nil {
t.Fatal(err)
}
if string(result) != testData {
t.Fatalf("expected %q, got %q", testData, result)
}
}
func TestFirstWriteAfterReadDone(t *testing.T) {
writeRecorder := &bytes.Buffer{}
br, cw := NewWriteAfterReader(&bytes.Buffer{}, writeRecorder)
if _, err := io.Copy(ioutil.Discard, br); err != nil {
t.Fatalf("copy from busyreader: %v", err)
}
testData := "test data"
if _, err := io.Copy(cw, testReader(testData)); err != nil {
t.Fatalf("copy test data: %v", err)
}
if err := cw.Flush(); err != nil {
t.Fatalf("flush error: %v", err)
}
if result := writeRecorder.String(); result != testData {
t.Fatalf("expected %q, got %q", testData, result)
}
}
func TestWriteDelay(t *testing.T) {
writeRecorder := &bytes.Buffer{}
w := &complainingWriter{Writer: writeRecorder}
br, cw := NewWriteAfterReader(&bytes.Buffer{}, w)
testData1 := "1 test"
if _, err := io.Copy(cw, testReader(testData1)); err != nil {
t.Fatalf("error on first copy: %v", err)
}
// Unblock the coupled writer by draining the reader
if _, err := io.Copy(ioutil.Discard, br); err != nil {
t.Fatalf("copy from busyreader: %v", err)
}
// Now it is no longer an error if 'w' receives a Write()
w.CheerUp()
testData2 := "2 experiment"
if _, err := io.Copy(cw, testReader(testData2)); err != nil {
t.Fatalf("error on second copy: %v", err)
}
if err := cw.Flush(); err != nil {
t.Fatalf("flush error: %v", err)
}
expected := testData1 + testData2
if result := writeRecorder.String(); result != expected {
t.Fatalf("total write: expected %q, got %q", expected, result)
}
}
func TestComplainingWriterSanity(t *testing.T) {
recorder := &bytes.Buffer{}
w := &complainingWriter{Writer: recorder}
testData := "test data"
if _, err := io.Copy(w, testReader(testData)); err == nil {
t.Error("error expected, none received")
}
w.CheerUp()
if _, err := io.Copy(w, testReader(testData)); err != nil {
t.Errorf("copy after CheerUp: %v", err)
}
if result := recorder.String(); result != testData {
t.Errorf("expected %q, got %q", testData, result)
}
}
func testReader(data string) io.Reader {
return iotest.OneByteReader(bytes.NewBuffer([]byte(data)))
}
type complainingWriter struct {
happy bool
io.Writer
}
func (comp *complainingWriter) Write(data []byte) (int, error) {
if comp.happy {
return comp.Writer.Write(data)
}
return 0, fmt.Errorf("I am unhappy about you wanting to write %q", data)
}
func (comp *complainingWriter) CheerUp() {
comp.happy = true
}
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