Function TestRotatedFile

cmd/syncthing/monitor_test.go:17–85

(t *testing.T)

)

func TestRotatedFile(t *testing.T) {
	// Verify that log rotation happens.

	dir := t.TempDir()

	open := func(name string) (io.WriteCloser, error) {
		f, err := os.Create(name)
		t.Cleanup(func() {
			if f != nil {
				_ = f.Close()
			}
		})

		return f, err
	}

	logName := filepath.Join(dir, "log.txt")
	testData := []byte("12345678\n")
	maxSize := int64(len(testData) + len(testData)/2)

	// We allow the log file plus two rotated copies.
	rf, err := newRotatedFile(logName, open, maxSize, 2)
	if err != nil {
		t.Fatal(err)
	}

	// Write some bytes.
	if _, err := rf.Write(testData); err != nil {
		t.Fatal(err)
	}
	// They should be in the log.
	checkSize(t, logName, len(testData))
	checkNotExist(t, logName+".0")

	// Write some more bytes. We should rotate and write into a new file as the
	// new bytes don't fit.
	if _, err := rf.Write(testData); err != nil {
		t.Fatal(err)
	}
	checkSize(t, logName, len(testData))
	checkSize(t, numberedFile(logName, 0), len(testData))
	checkNotExist(t, logName+".1")

	// Write another byte. That should fit without causing an extra rotate.
	_, _ = rf.Write([]byte{42})
	checkSize(t, logName, len(testData)+1)
	checkSize(t, numberedFile(logName, 0), len(testData))
	checkNotExist(t, numberedFile(logName, 1))

	// Write some more bytes. We should rotate and write into a new file as the
	// new bytes don't fit.
	if _, err := rf.Write(testData); err != nil {
		t.Fatal(err)
	}
	checkSize(t, logName, len(testData))
	checkSize(t, numberedFile(logName, 0), len(testData)+1) // the one we wrote extra to, now rotated
	checkSize(t, numberedFile(logName, 1), len(testData))
	checkNotExist(t, numberedFile(logName, 2))