diff options
Diffstat (limited to 'workhorse/internal/helper/writeafterreader_test.go')
-rw-r--r-- | workhorse/internal/helper/writeafterreader_test.go | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/workhorse/internal/helper/writeafterreader_test.go b/workhorse/internal/helper/writeafterreader_test.go new file mode 100644 index 00000000000..67cb3e6e542 --- /dev/null +++ b/workhorse/internal/helper/writeafterreader_test.go @@ -0,0 +1,115 @@ +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 +} |