Use panic when Watch called before read

config.go

@@ -301,7 +301,7 @@ func (c *ConfReader) WithPrefix(prefix string) *ConfReader {
 // This will ensure that the config is not reloaded while you are accessing it.
 func (c *ConfReader) Watch() *sync.RWMutex {
 	if c.configStruct == nil {
-		log.Fatalln("ConfReader: config struct is not set. Call Read before Watch")
+		panic("ConfReader: config struct is not set. Call Read before Watch")
 	}
 	rwmutex := &sync.RWMutex{}
 

config_test.go

@@ -125,18 +125,25 @@ func Test_WatchWithFile(t *testing.T) {
 	resetFlags()
 	nc := &FullConfig{}
 
-	err := os.Mkdir("testdata/tmp", 0755)
-	if err != nil {
+	if err := os.Mkdir("testdata/tmp", 0755); err != nil {
 		t.Fatal(err)
 	}
-	err = os.WriteFile("testdata/tmp/changing_file.json", []byte(`{"verbose":"true"}`), 0644)
-	if err != nil {
+	defer os.RemoveAll("testdata/tmp")
+
+	if err := os.WriteFile("testdata/tmp/changing_file.json", []byte(`{"verbose":"true"}`), 0644); err != nil {
 		t.Fatal(err)
 	}
-	defer os.RemoveAll("testdata/tmp")
+
 	confReader := NewConfReader("changing_file")
 	confReader.configDirs = []string{"testdata/tmp"}
-	err = confReader.Read(nc)
+
+	t.Run("callWatchBeforeRead", func(t *testing.T) {
+		assert.Panics(t, func() {
+			confReader.Watch()
+		})
+	})
+
+	err := confReader.Read(nc)
 	if assert.NoError(t, err) {
 		assert.Equal(t, true, nc.Verbose)
 	}
@@ -164,6 +171,16 @@ func Test_WatchWithFile(t *testing.T) {
 		time.Sleep(10 * time.Millisecond)
 		assert.Equal(t, true, nc.Verbose)
 	})
+
+	t.Run("doesNotFilaIfFileDeleted", func(t *testing.T) {
+		err = os.Remove("testdata/tmp/changing_file.json")
+		if err != nil {
+			t.Fatal(err)
+		}
+		time.Sleep(10 * time.Millisecond)
+		assert.Equal(t, true, nc.Verbose)
+	})
+
 }
 
 type dmParent struct {