chore(tests): add directive-styles tests

projects/cdk/services/test/directive-styles.service.spec.ts

@@ -0,0 +1,34 @@
+import {TuiDirectiveStylesService} from '../directive-styles.service';
+
+describe('TuiDirectiveStylesService service', () => {
+    it('does nothing with renderer if there is no head.querySelector', () => {
+        let called = 0;
+        const stub: any = {
+            head: {
+                querySelector: () => ++called,
+            },
+        };
+
+        const service = new TuiDirectiveStylesService(stub, null as any);
+
+        service.addStyle('test', 'test');
+
+        expect(called).toBe(1);
+    });
+
+    it('add styles to renderer', () => {
+        let called = 0;
+
+        const rendererStub: any = {
+            createElement: () => document.createElement('div'),
+            setProperty: () => ++called,
+            setAttribute: () => ++called,
+        };
+
+        const service = new TuiDirectiveStylesService(document, rendererStub);
+
+        service.addStyle('p { color: black; }', 'test');
+
+        expect(called).toBe(2);
+    });
+});