Add platform service

src/app/shared/platform.service.spec.ts

@@ -0,0 +1,59 @@
+import { IPlatformService, PlatformService } from './platform.service'
+import { async, TestBed } from '@angular/core/testing'
+import { PLATFORM_ID } from '@angular/core'
+
+describe('PlatformService', () => {
+  let service: IPlatformService;
+
+  describe('PlatformService browser', () => {
+    beforeEach(async(() => {
+      TestBed.configureTestingModule({
+        providers: [
+          PlatformService,
+          { provide: PLATFORM_ID, useValue: 'browser' }
+        ]
+      })
+    }));
+
+    beforeEach(async(() => {
+      service = TestBed.get(PlatformService)
+    }));
+
+    afterEach(async(() => {
+      TestBed.resetTestingModule()
+    }));
+
+    it('should construct', async(() => {
+      expect(service).not.toBeNull()
+    }));
+
+    it('should be browser', async(() => {
+      expect(service.isBrowser).toEqual(true);
+      expect(service.isServer).toEqual(false)
+    }));
+  });
+
+  describe('PlatformService server', () => {
+    beforeEach(async(() => {
+      TestBed.configureTestingModule({
+        providers: [
+          PlatformService,
+          { provide: PLATFORM_ID, useValue: 'server' }
+        ]
+      })
+    }));
+
+    beforeEach(async(() => {
+      service = TestBed.get(PlatformService)
+    }));
+
+    afterEach(async(() => {
+      TestBed.resetTestingModule()
+    }));
+
+    it('should be server', async(() => {
+      expect(service.isServer).toEqual(true);
+      expect(service.isBrowser).toEqual(false)
+    }))
+  })
+});

src/app/shared/platform.service.ts

@@ -0,0 +1,20 @@
+import { Inject, Injectable, PLATFORM_ID } from '@angular/core'
+import { isPlatformBrowser, isPlatformServer } from '@angular/common'
+
+export interface IPlatformService {
+  readonly isBrowser: boolean
+  readonly isServer: boolean
+}
+
+@Injectable()
+export class PlatformService implements IPlatformService {
+  constructor( @Inject(PLATFORM_ID) private platformId: any) { }
+
+  public get isBrowser(): boolean {
+    return isPlatformBrowser(this.platformId)
+  }
+
+  public get isServer(): boolean {
+    return isPlatformServer(this.platformId)
+  }
+}