// create a tempfile, add a hook, see if hook gets called
// when file changes. TODO: test all other fs events.
func TestWatchFile(t *testing.T) {
assert := assert.New(t)
file_content := "tst1"
tf, _ := ioutil.TempFile("", "gems.lock")
tf.Write([]byte(file_content))
tf.Close()
timer := time.Tick(5 * time.Second)
cbInvoked := make(chan bool)
testcb := func(nop *WatchedFile) {
cbInvoked <- true
}
wfile := NewWatchedFile(tf.Name(), testcb)
wfile.StartListener()
// let's make sure the file got written to
read_contents, _ := wfile.Contents()
assert.Equal(file_content, string(read_contents))
// but really we want to know if the
// callback was ever invoked
select {
case invoked := <-cbInvoked:
assert.True(invoked)
case _ = <-timer:
assert.True(false)
}
// solid. on boot it worked. But what
// if we changed the file contents?
newContents := []byte("HelloWorld\n")
err := ioutil.WriteFile(tf.Name(), newContents, 0777)
assert.Nil(err)
// let's wait again just in case.
select {
case invoked := <-cbInvoked:
assert.True(invoked)
case _ = <-timer:
assert.True(false)
}
wfile.StopListening()
}
func TestWatchFileHookLoop(t *testing.T) {
assert := assert.New(t)
file_content := []byte("tst1")
tf, _ := ioutil.TempFile("", "gems.lock")
tf.Write([]byte(file_content))
tf.Close()
file_name := tf.Name()
cbInvoked := make(chan bool, 10)
mutex := &sync.Mutex{}
counter := 0
testcb := func(wfile *WatchedFile) {
mutex.Lock()
counter++
mutex.Unlock()
cbInvoked <- true
}
wfile := NewWatchedFile(file_name, testcb)
// file gets read on hook add
wfile.StartListener()
<-cbInvoked
// // file gets read on rewrite
fmt.Println("--> write 2")
file_content = []byte("hello test1")
err := ioutil.WriteFile(file_name, file_content, 0644)
<-cbInvoked
// we remove and recreate the file,
// triggering a rehook and re-read
fmt.Println("--> removal 1")
os.Remove(file_name)
fmt.Println("--> write 3")
file_content = []byte("hello test2")
err = ioutil.WriteFile(file_name, file_content, 0644)
assert.Nil(err)
<-cbInvoked
// we write to the file, triggering
// another re-read
fmt.Println("--> write 4")
file_content = []byte("hello test3")
err = ioutil.WriteFile(file_name, file_content, 0644)
assert.Nil(err)
<-cbInvoked
// we remove and recreate the file,
// triggering a rehook yet another re-read
fmt.Println("--> removal 2")
os.Remove(file_name)
fmt.Println("--> write 5")
file_content = []byte("hello test4")
err = ioutil.WriteFile(file_name, file_content, 0644)
assert.Nil(err)
<-cbInvoked
fmt.Println("--> write 6")
file_content = []byte("hello test5")
err = ioutil.WriteFile(file_name, file_content, 0644)
assert.Nil(err)
<-cbInvoked
fmt.Println("cleaning up\n")
// we wrote the file five times, plus the init read
mutex.Lock()
assert.True(counter >= 6)
mutex.Unlock()
// cleanup
wfile.StopListening()
os.Remove(file_name)
}