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error when starting BlockUIService in ngOnInit

See original GitHub issue

I’m currently trying to upgrade my application to Angular 9 and when starting the ng-block-ui service in an ngOnInit hook i get this error in my console:

ng-block-ui: TypeError: Cannot convert undefined or null to object
    at Function.from (<anonymous>)
    at BlockUIDirective.push../node_modules/ng-block-ui/__ivy_ngcc__/fesm5/ng-block-ui.js.BlockUIDirective.isComponentInTemplate (ng-block-ui.js:836)
    at BlockUIDirective.push../node_modules/ng-block-ui/__ivy_ngcc__/fesm5/ng-block-ui.js.BlockUIDirective.ngOnInit (ng-block-ui.js:802)
    at callHook (core.js:2614)
    at callHooks (core.js:2584)
    at executeInitAndCheckHooks (core.js:2537)
    at selectIndexInternal (core.js:6141)
    at Module.ɵɵadvance (core.js:6114)
    at RootComponent_Template (root.component.html:54)
    at executeTemplate (core.js:7495)

BlockUIModule.forRoot() declared at top level module. The BlockUIDirective is used in my RootComponent.

Config:

Angular: 9.0.1
ng-block-ui: 3.0.0-beta.4

My suggestion is that this code:

private isComponentInTemplate(element: any): boolean {
    let { children } = element || [];
    children = Array.from(children).reverse();
    return children.some((el: any) => el.localName === 'block-ui');
  }

can be changed to

private isComponentInTemplate(element: any): boolean {
    let { children = [] } = element;
    children = Array.from(children).reverse();
    return children.some((el: any) => el.localName === 'block-ui');
  }

I did not wanted to do a pull request for one line change.