114 lines
2.7 KiB
Go
114 lines
2.7 KiB
Go
package helper
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"io"
|
|
"testing"
|
|
"testing/iotest"
|
|
)
|
|
|
|
func TestBusyReader(t *testing.T) {
|
|
testData := "test data"
|
|
r := testReader(testData)
|
|
br, _ := NewWriteAfterReader(r, &bytes.Buffer{})
|
|
|
|
result, err := io.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(io.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(io.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
|
|
}
|