Wrap chart js constructor in a function and provide it with an InjectionToken

chart-js-wrap.ts

export function chartBuilder(item: ChartItem, options: ChartConfiguration) {
    return new Chart(item, options);
}
// The 👆 function and the Token 👇
const ChartBuilderToken = new InjectionToken<typeof chartBuilder>(
    'The Chart.js instance builder'
);

@Component({
    ...,
    // provide it 👇
    providers: [{ provide: ChartBuilderToken, useValue: chartBuilder }],
})
export class ChartComponent {
    @ViewChild('canvas')
    canvas: ElementRef | undefined;
    chart: Chart | undefined;

    constructor(
        // 👇 use the special Inject syntax to tell Angular what you want
        @Inject(ChartBuilderToken) private buildChart: typeof chartBuilder
    ) {}

    ngAfterViewInit() {
        this.chart = this.buildChart(this.canvas?.nativeElement, { /*...*/ });
    }
}