Function TestLoggerV2PrintFuncDiscardOnlyInfo

grpclog/internal/loggerv2_test.go:134–162

TestLoggerV2PrintFuncDiscardOnlyInfo ensures that logs at the INFO level are discarded when set to io.Discard, while logs at other levels (WARN, ERROR) are still printed. It does this by using a custom error function that raises an error if the logger attempts to print at the INFO level, ensuring ea

(t *testing.T)

// an error if the logger attempts to print at the INFO level, ensuring early
// return when io.Discard is used.
func TestLoggerV2PrintFuncDiscardOnlyInfo(t *testing.T) {
	buffers := []*bytes.Buffer{nil, new(bytes.Buffer), new(bytes.Buffer)}
	logger := NewLoggerV2(io.Discard, buffers[warningLog], buffers[errorLog], LoggerV2Config{})
	loggerTp := logger.(*loggerT)

	// test that output doesn't call expensive printf funcs on an io.Discard logger
	sprintf = makeSprintfErr(t)
	sprint = makeSprintErr(t)
	sprintln = makeSprintErr(t)

	loggerTp.output(infoLog, "something")

	sprintf = fmt.Sprintf
	sprint = fmt.Sprint
	sprintln = fmt.Sprintln

	loggerTp.output(errorLog, logFuncStr)
	warnB, err := buffers[warningLog].ReadBytes('\n')
	if err != nil {
		t.Fatalf("level %v: %v", warningLog, err)
	}
	checkLogContainsFuncStr(t, warnB)

	errB, err := buffers[errorLog].ReadBytes('\n')
	if err != nil {
		t.Fatalf("level %v: %v", errorLog, err)
	}
	checkLogContainsFuncStr(t, errB)
}

func TestLoggerV2PrintFuncNoDiscard(t *testing.T) {
	buffers := []*bytes.Buffer{new(bytes.Buffer), new(bytes.Buffer), new(bytes.Buffer)}