Add Stringer and test multiple events

- Add String() implementation to Event and Action types
- Add test to check multiple events

Author: opcoder0

fanotify_api.go

@@ -5,7 +5,9 @@ package fanotify
 
 import (
 	"errors"
+	"fmt"
 	"os"
+	"strings"
 
 	"golang.org/x/sys/unix"
 )
@@ -99,9 +101,9 @@ func NewListener(mountpointPath string, maxEvents uint, withName bool) (*Listene
 // The events are pushed into the Listener's `Events` buffered channel.
 // The function panics if there nothing to watch.
 func (l *Listener) Start() {
-	if len(l.watches) == 0 {
-		panic("Nothing to watch. Add Directory/File to the listener to watch")
-	}
+	//if len(l.watches) == 0 {
+	//		panic("Nothing to watch. Add Directory/File to the listener to watch")
+	//}
 	var fds [2]unix.PollFd
 	// Fanotify Fd
 	fds[0].Fd = int32(l.fd)
@@ -185,3 +187,33 @@ func (actions Action) Has(a Action) bool {
 func (actions Action) Or(a Action) Action {
 	return actions | a
 }
+
+// String prints action
+func (a Action) String() string {
+	var actions = map[Action]string{
+		unix.FAN_ACCESS:        "Access",
+		unix.FAN_MODIFY:        "Modify",
+		unix.FAN_CLOSE_WRITE:   "CloseWrite",
+		unix.FAN_CLOSE_NOWRITE: "CloseNoWrite",
+		unix.FAN_OPEN:          "Open",
+		unix.FAN_OPEN_EXEC:     "OpenExec",
+		unix.FAN_ATTRIB:        "AttribChange",
+		unix.FAN_CREATE:        "Create",
+		unix.FAN_DELETE:        "Delete",
+		unix.FAN_DELETE_SELF:   "SelfDelete",
+		unix.FAN_MOVED_FROM:    "MovedFrom",
+		unix.FAN_MOVED_TO:      "MovedTo",
+		unix.FAN_MOVE_SELF:     "SelfMove",
+	}
+	var actionList []string
+	for k, v := range actions {
+		if a.Has(k) {
+			actionList = append(actionList, v)
+		}
+	}
+	return strings.Join(actionList, ",")
+}
+
+func (e Event) String() string {
+	return fmt.Sprintf("Fd:(%d), Pid:(%d), Action:(%s), Path:(%s), Filename:(%s)", e.Fd, e.Pid, e.Actions, e.Path, e.FileName)
+}

fanotify_test.go

@@ -381,3 +381,59 @@ func TestActions(t *testing.T) {
 	assert.True(t, actions.Has(FileModified))
 	assert.True(t, actions.Has(FileDeleted))
 }
+
+func TestMultipleEvents(t *testing.T) {
+	l, err := NewListener("/", 4096, true)
+	assert.Nil(t, err)
+	assert.NotNil(t, l)
+	go l.Start()
+	defer l.Stop()
+
+	watchDir := t.TempDir()
+	actions := FileOrDirCreated.Or(FileModified.Or(FileDeleted))
+	l.AddWatch(watchDir, actions)
+	testFile := fmt.Sprintf("%s/test.txt", watchDir)
+	pid, err := runAsCmd("touch", testFile) // create file
+	assert.Nil(t, err)
+	select {
+	case <-time.After(100 * time.Millisecond):
+		t.Error("Timeout Error: FileCreated event not received")
+	case event := <-l.Events:
+		assert.Equal(t, fmt.Sprintf("%s/%s", event.Path, event.FileName), testFile)
+		assert.Equal(t, event.Pid, pid)
+		assert.True(t, event.Actions.Has(FileCreated))
+		t.Logf("Received: (%s)", event)
+	}
+	touchPid := pid
+
+	// modify file
+	os.WriteFile(testFile, []byte("test string"), 0666)
+	pid = os.Getpid()
+	select {
+	case <-time.After(100 * time.Millisecond):
+		t.Error("Timeout Error: FileModified event not received")
+	case event := <-l.Events:
+		assert.Equal(t, fmt.Sprintf("%s/%s", event.Path, event.FileName), testFile)
+		assert.Equal(t, event.Pid, pid)
+		assert.True(t, event.Actions.Has(FileModified))
+		t.Logf("Received: (%s)", event)
+	}
+
+	t.Logf("Pids: Self(%d), Touch(%d)", pid, touchPid)
+	// NOTE: os.WriteFile sends two modify events; so draining them
+	for len(l.Events) > 0 {
+		e := <-l.Events
+		t.Logf("Drain-Event: (%s)", e)
+	}
+	pid, err = runAsCmd("rm", "-f", testFile)
+	assert.Nil(t, err)
+	select {
+	case <-time.After(100 * time.Millisecond):
+		t.Error("Timeout Error: FileDeleted event not received")
+	case event := <-l.Events:
+		assert.Equal(t, fmt.Sprintf("%s/%s", event.Path, event.FileName), testFile)
+		assert.Equal(t, event.Pid, pid)
+		assert.True(t, event.Actions.Has(FileDeleted))
+		t.Logf("Received: (%s)", event)
+	}
+}