confwatcher: add tests

internal/confwatcher/confwatcher_test.go

@@ -0,0 +1,126 @@
+package confwatcher
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func writeTempFile(byts []byte) (string, error) {
+	tmpf, err := ioutil.TempFile(os.TempDir(), "confwatcher-")
+	if err != nil {
+		return "", err
+	}
+	defer tmpf.Close()
+
+	_, err = tmpf.Write(byts)
+	if err != nil {
+		return "", err
+	}
+
+	return tmpf.Name(), nil
+}
+
+func TestNoFile(t *testing.T) {
+	_, err := New("/nonexistent")
+	require.Error(t, err)
+}
+
+func TestFileWrite(t *testing.T) {
+	fpath, err := writeTempFile([]byte("{}"))
+	require.NoError(t, err)
+
+	w, err := New(fpath)
+	require.NoError(t, err)
+	defer w.Close()
+
+	func() {
+		f, err := os.Create(fpath)
+		require.NoError(t, err)
+		defer f.Close()
+
+		_, err = f.Write([]byte("{}"))
+		require.NoError(t, err)
+	}()
+
+	select {
+	case <-w.Watch():
+	case <-time.After(500 * time.Millisecond):
+		t.Errorf("timed out")
+		return
+	}
+}
+
+func TestFileWriteMultipleTimes(t *testing.T) {
+	fpath, err := writeTempFile([]byte("{}"))
+	require.NoError(t, err)
+
+	w, err := New(fpath)
+	require.NoError(t, err)
+	defer w.Close()
+
+	func() {
+		f, err := os.Create(fpath)
+		require.NoError(t, err)
+		defer f.Close()
+
+		_, err = f.Write([]byte("{}"))
+		require.NoError(t, err)
+	}()
+
+	time.Sleep(10 * time.Millisecond)
+
+	func() {
+		f, err := os.Create(fpath)
+		require.NoError(t, err)
+		defer f.Close()
+
+		_, err = f.Write([]byte("{}"))
+		require.NoError(t, err)
+	}()
+
+	select {
+	case <-w.Watch():
+	case <-time.After(500 * time.Millisecond):
+		t.Errorf("timed out")
+		return
+	}
+
+	select {
+	case <-time.After(500 * time.Millisecond):
+	case <-w.Watch():
+		t.Errorf("should not happen")
+		return
+	}
+}
+
+/*func TestFileDeleteCreate(t *testing.T) {
+	fpath, err := writeTempFile([]byte("{}"))
+	require.NoError(t, err)
+
+	w, err := New(fpath)
+	require.NoError(t, err)
+	defer w.Close()
+
+    os.Remove(fpath)
+    time.Sleep(10 * time.Millisecond)
+
+    func() {
+        f, err := os.Create(fpath)
+        require.NoError(t, err)
+        defer f.Close()
+
+        _, err = f.Write([]byte("{}"))
+        require.NoError(t, err)
+    }()
+
+	select {
+	case <-w.Watch():
+	//case <-time.After(500 * time.Millisecond):
+	//	t.Errorf("timed out")
+    //    return
+	}
+}*/