added tests for the new object-grid-component onInit code

src/app/shared/object-grid/object-grid.component.spec.ts

@@ -0,0 +1,224 @@
+import { cold, hot } from 'jasmine-marbles';
+import { map } from 'rxjs/operators';
+import { WidthCategory } from '../host-window.service';
+import { ObjectGridComponent } from './object-grid.component';
+
+describe('ObjectGridComponent', () => {
+  const testObjects = [
+    { one: 1 },
+    { two: 2 },
+    { three: 3 },
+    { four: 4 },
+    { five: 5 },
+    { six: 6 },
+    { seven: 7 },
+    { eight: 8 },
+    { nine: 9 },
+    { ten: 10 }
+  ];
+  const mockRD = {
+    payload: {
+      page: testObjects
+    }
+  } as any;
+
+  describe('the number of columns', () => {
+
+    it('should be 3 for xl screens', () => {
+      const hostWindowService = {
+        widthCategory: hot('a', { a: WidthCategory.XL }),
+      } as any;
+      const comp = new ObjectGridComponent(hostWindowService);
+
+      (comp as any)._objects$ = hot('b', { b: mockRD });
+
+      comp.ngOnInit();
+
+      const expected = cold('c', { c: 3 });
+
+      const result = comp.columns$.pipe(
+        map((columns) => columns.length)
+      );
+
+      expect(result).toBeObservable(expected);
+    });
+
+    it('should be 3 for lg screens', () => {
+      const hostWindowService = {
+        widthCategory: hot('a', { a: WidthCategory.LG }),
+      } as any;
+      const comp = new ObjectGridComponent(hostWindowService);
+
+      (comp as any)._objects$ = hot('b', { b: mockRD });
+
+      comp.ngOnInit();
+
+      const expected = cold('c', { c: 3 });
+
+      const result = comp.columns$.pipe(
+        map((columns) => columns.length)
+      );
+
+      expect(result).toBeObservable(expected);
+    });
+
+    it('should be 2 for md screens', () => {
+      const hostWindowService = {
+        widthCategory: hot('a', { a: WidthCategory.MD }),
+      } as any;
+      const comp = new ObjectGridComponent(hostWindowService);
+
+      (comp as any)._objects$ = hot('b', { b: mockRD });
+
+      comp.ngOnInit();
+
+      const expected = cold('c', { c: 2 });
+
+      const result = comp.columns$.pipe(
+        map((columns) => columns.length)
+      );
+
+      expect(result).toBeObservable(expected);
+    });
+
+    it('should be 2 for sm screens', () => {
+      const hostWindowService = {
+        widthCategory: hot('a', { a: WidthCategory.SM }),
+      } as any;
+      const comp = new ObjectGridComponent(hostWindowService);
+
+      (comp as any)._objects$ = hot('b', { b: mockRD });
+
+      comp.ngOnInit();
+
+      const expected = cold('c', { c: 2 });
+
+      const result = comp.columns$.pipe(
+        map((columns) => columns.length)
+      );
+
+      expect(result).toBeObservable(expected);
+    });
+
+    it('should be 1 for xs screens', () => {
+      const hostWindowService = {
+        widthCategory: hot('a', { a: WidthCategory.XS }),
+      } as any;
+      const comp = new ObjectGridComponent(hostWindowService);
+
+      (comp as any)._objects$ = hot('b', { b: mockRD });
+
+      comp.ngOnInit();
+
+      const expected = cold('c', { c: 1 });
+
+      const result = comp.columns$.pipe(
+        map((columns) => columns.length)
+      );
+
+      expect(result).toBeObservable(expected);
+    });
+
+  });
+
+  describe('The ordering of the content', () => {
+    it('should be left to right for XL screens', () => {
+      const hostWindowService = {
+        widthCategory: hot('a', { a: WidthCategory.XL }),
+      } as any;
+      const comp = new ObjectGridComponent(hostWindowService);
+
+      (comp as any)._objects$ = hot('b', { b: mockRD });
+
+      comp.ngOnInit();
+
+      const expected = cold('c', { c: [
+          [testObjects[0], testObjects[3], testObjects[6], testObjects[9]],
+          [testObjects[1], testObjects[4], testObjects[7]],
+          [testObjects[2], testObjects[5], testObjects[8]]
+        ] });
+
+      const result = comp.columns$;
+
+      expect(result).toBeObservable(expected);
+    });
+
+    it('should be left to right for LG screens', () => {
+      const hostWindowService = {
+        widthCategory: hot('a', { a: WidthCategory.LG }),
+      } as any;
+      const comp = new ObjectGridComponent(hostWindowService);
+
+      (comp as any)._objects$ = hot('b', { b: mockRD });
+
+      comp.ngOnInit();
+
+      const expected = cold('c', { c: [
+          [testObjects[0], testObjects[3], testObjects[6], testObjects[9]],
+          [testObjects[1], testObjects[4], testObjects[7]],
+          [testObjects[2], testObjects[5], testObjects[8]]
+        ] });
+
+      const result = comp.columns$;
+
+      expect(result).toBeObservable(expected);
+    });
+
+    it('should be left to right for MD screens', () => {
+      const hostWindowService = {
+        widthCategory: hot('a', { a: WidthCategory.MD }),
+      } as any;
+      const comp = new ObjectGridComponent(hostWindowService);
+
+      (comp as any)._objects$ = hot('b', { b: mockRD });
+
+      comp.ngOnInit();
+
+      const expected = cold('c', { c: [
+          [testObjects[0], testObjects[2], testObjects[4], testObjects[6], testObjects[8]],
+          [testObjects[1], testObjects[3], testObjects[5], testObjects[7], testObjects[9]],
+        ] });
+
+      const result = comp.columns$;
+
+      expect(result).toBeObservable(expected);
+    });
+
+    it('should be left to right for SM screens', () => {
+      const hostWindowService = {
+        widthCategory: hot('a', { a: WidthCategory.SM }),
+      } as any;
+      const comp = new ObjectGridComponent(hostWindowService);
+
+      (comp as any)._objects$ = hot('b', { b: mockRD });
+
+      comp.ngOnInit();
+
+      const expected = cold('c', { c: [
+          [testObjects[0], testObjects[2], testObjects[4], testObjects[6], testObjects[8]],
+          [testObjects[1], testObjects[3], testObjects[5], testObjects[7], testObjects[9]],
+        ] });
+
+      const result = comp.columns$;
+
+      expect(result).toBeObservable(expected);
+    });
+
+    it('should be top to bottom for XS screens', () => {
+      const hostWindowService = {
+        widthCategory: hot('a', { a: WidthCategory.XS }),
+      } as any;
+      const comp = new ObjectGridComponent(hostWindowService);
+
+      (comp as any)._objects$ = hot('b', { b: mockRD });
+
+      comp.ngOnInit();
+
+      const expected = cold('c', { c: [ testObjects ] });
+
+      const result = comp.columns$;
+
+      expect(result).toBeObservable(expected);
+    });
+  });
+});