Item reveal events not fired if initialising WowService with no arguments

[MichaelNel]

Bug Report or Feature Request (mark with an x)

- [x] bug report -> please search issues before submitting
- [ ] feature request

Repro steps

1. Initialise the WowService with no arguments.
2. Subscribe to item revealed events.
3. Reveal the element.

The event is not fired.

Desired functionality

The event should be fired for registered subscriptions.

Mention any other details that might be useful

It's a typo, should be passing conf when initialising wow js in the WowService. For a temporary fix until the library is fixed you can pass in an empy object when initialising the WowService e.g. WowService.init({}).

  init(config?: NgwWowConfig): void {
    if (this.window) { // For Angular Universal suport
      let conf = config || {};
      // Set callback hook:
      conf.callback = () => this.itemRevealedSource.next();

      // Initializes the library
      new WOW(config).init();
    }
}