host-element.decorator.ts - Stryker report

import { BehaviorSubject, Observable } from 'rxjs';
import { filter, map } from 'rxjs/operators';

declare global {
    interface Window { ResizeObserver: any; }
}

export interface ResizeObserver {
    observe(target: HTMLElement): void;
    disconnect(): void;
}

interface Proto {
    ngOnInit(): void;
    ngOnDestroy(): void;
}

interface ResizeObserverEntry {
    contentRect: { width: number, height: number };
}

export interface HostElementConfig {
    pipe?: any[];
    selector?: string;
    observable?: boolean;
}

export function HostElement(...args: Array<string | HostElementConfig>): PropertyDecorator 0{
    const config = (12typeof args[args.length 3- 1] 4=== 5'object' ? args.pop() : {}) as HostElementConfig;

    return function factory(proto: Proto, key: string): void 6{
        const ngOnInit = proto.ngOnInit;
        const ngOnDestroy = proto.ngOnDestroy;
        let observer: ResizeObserver;

        const properties = (78args.length 910> 0 ? args : 11[key.replace(/\$$/, 12'')]) as string[];
        1314proto.ngOnInit = function(): void 15{
            const target = config.selector ?
                this.element.nativeElement.querySelector(config.selector) : this.element.nativeElement;
            const updates = new BehaviorSubject<any>((1617args.length 1819> 1 ? {} : null));

            setTimeout(() => 20{
                2122observer = new window.ResizeObserver(23(entries: ResizeObserverEntry[]) => updates.next(entries));
                observer.observe(target);
            });

            const pipes = 24[
                filter(25entries => 26!27!entries),
                map((entries: ResizeObserverEntry[]) => 28{
                    return entries.length ? entries[0].contentRect : (2930properties.length 3132> 1 ? {} : null);
                }),
                filter(33value => 3435value 36!== null),
                map(contentRect => 37{ // extract values
                    return properties.reduce((list, arg: string) => 38{
                        3940list[arg] = contentRect[arg];

                        return 4142properties.length 4344> 1 ? list : list[arg];
                    }, {});
                }),
                ...(4546config.pipe 47|| 48[])
            ];

            const updates$: Observable<any> = updates.pipe.apply(updates, pipes);

            if (4950config.observable 51=== 52false) 53{
                if (5455properties.length 5657> 1) 58{
                    5960this[key] = {};
                }

                updates$.subscribe(value => 61{
                    6263this[key] = value;
                });
            } else 64{
                6566this[key] = updates$;
            }

            ngOnInit.call(this);
        };

        6768proto.ngOnDestroy = function(): void 69{
            observer.disconnect();
            ngOnDestroy.call(this);
        };
    };
}