Using _customRouteId in grouped topics is broken

[swashbuck]

Subject of the issue

Using _customRouteId for a button is broken if a valid model cannot first be found for the type. For example, if there is no "next" sibling content object in a menu group and you set the _customRouteId to the first content object in the next group, the button will not be shown.

When the code goes through and gets the valid models (e.g. get the next sibling content object for the _next button model), it will exit if no model is found.

adapt-pageNav/js/PageNavModel.js

Lines 45 to 46 in 330a72b

	let buttonModel = buttonTypeModels[type];
	if (!buttonModel) continue;

So, it never gets a chance to check for a _customRouteId:

adapt-pageNav/js/PageNavModel.js

Lines 48 to 50 in 330a72b

	// Find buttonModel from config._customRouteId if not found in defined type
	if (buttonConfig._customRouteId) {
	buttonModel = data.findById(buttonConfig._customRouteId);

Your environment

• FW 5.39.7
• Page Nav 3.1.4

Steps to reproduce

Set up a menu with grouping. Each group contains one topic:

• Group 1 - co-100
• Group 2 - co-200

For the _next button in co-100, set the _customRouteId to co-200 since it can't naturally find what the next content object is.

For the _previous button in co-200, set the _customRouteId to co-100 since it can't naturally find what the previous content object is.

Expected behaviour

The Next button in co-100 and the Previous button in co-200 should both be visible.