feat(core): add cross-origin strategy

npm/ng-packs/packages/core/src/lib/strategies/cross-origin.strategy.ts

@@ -0,0 +1,17 @@
+export class CrossOriginStrategy {
+  constructor(public crossorigin: 'anonymous' | 'use-credentials', public integrity?: string) {}
+
+  setCrossOrigin<T extends HTMLElement>(element: T) {
+    if (this.integrity) element.setAttribute('integrity', this.integrity);
+    element.setAttribute('crossorigin', this.crossorigin);
+  }
+}
+
+export const CROSS_ORIGIN_STRATEGY = {
+  Anonymous(integrity?: string) {
+    return new CrossOriginStrategy('anonymous', integrity);
+  },
+  UseCredentials(integrity?: string) {
+    return new CrossOriginStrategy('use-credentials', integrity);
+  },
+};

npm/ng-packs/packages/core/src/lib/strategies/index.ts

@@ -1 +1,2 @@
+export * from './cross-origin.strategy';
 export * from './dom.strategy';

npm/ng-packs/packages/core/src/lib/tests/cross-origin.strategy.spec.ts

@@ -0,0 +1,38 @@
+import { CrossOriginStrategy, CROSS_ORIGIN_STRATEGY } from '../strategies';
+import { uuid } from '../utils';
+
+describe('CrossOriginStrategy', () => {
+  describe('#setCrossOrigin', () => {
+    it('should set crossorigin attribute', () => {
+      const strategy = new CrossOriginStrategy('use-credentials');
+      const element = document.createElement('link');
+      strategy.setCrossOrigin(element);
+
+      expect(element.crossOrigin).toBe('use-credentials');
+    });
+
+    it('should set integrity attribute when given', () => {
+      const integrity = uuid();
+      const strategy = new CrossOriginStrategy('anonymous', integrity);
+      const element = document.createElement('link');
+      strategy.setCrossOrigin(element);
+
+      expect(element.crossOrigin).toBe('anonymous');
+      expect(element.getAttribute('integrity')).toBe(integrity);
+    });
+  });
+});
+
+describe('CROSS_ORIGIN_STRATEGY', () => {
+  test.each`
+    name                | integrity    | crossOrigin
+    ${'Anonymous'}      | ${undefined} | ${'anonymous'}
+    ${'Anonymous'}      | ${uuid()}    | ${'anonymous'}
+    ${'UseCredentials'} | ${undefined} | ${'use-credentials'}
+    ${'UseCredentials'} | ${uuid()}    | ${'use-credentials'}
+  `('should successfully map $name to CrossOriginStrategy', ({ name, integrity, crossOrigin }) => {
+    expect(CROSS_ORIGIN_STRATEGY[name](integrity)).toEqual(
+      new CrossOriginStrategy(crossOrigin, integrity),
+    );
+  });
+});