Function TestOnFlushCallback

log/buffered_test.go:95–130

(t *testing.T)

}

func TestOnFlushCallback(t *testing.T) {
	var (
		flushCount     uint32
		flushedEntries int
		buf            bytes.Buffer
	)

	callback := func(entries uint32) {
		flushCount++
		flushedEntries += int(entries)
	}

	// Do NOT specify a flush period because we want to be in control of the flushes done by this test.
	bufLog := NewBufferedLogger(&buf, 2,
		WithPrellocatedBuffer(bufferSize),
		WithFlushCallback(callback),
	)

	l := log.NewLogfmtLogger(bufLog)
	//nolint: loggercheck
	require.NoError(t, l.Log("line"))
	//nolint: loggercheck
	require.NoError(t, l.Log("line"))
	// first flush
	//nolint: loggercheck
	require.NoError(t, l.Log("line"))

	// pre-condition check: the last Log() call should have flushed previous entries.
	require.Equal(t, uint32(1), bufLog.Size())

	// force a second
	require.NoError(t, bufLog.Flush())

	require.Equal(t, uint32(2), flushCount)
	require.Len(t, strings.Split(buf.String(), "\n"), flushedEntries+1)
}

// outFile creates a real OS file for testing.
// We cannot use stdout/stderr since we need to read the contents afterwards to validate, and we have to write to a file