feat(api): add subscription server and client services and interfaces (#1470)

* feat(api): add subscription server and client services and interfaces

* fix(api): linter issues

* feat(models): add subscription invitations

* feat(api): add subscriptions invitation operations on server side

* fix(api): linter issues

packages/api/src/Domain/Client/Subscription/SubscriptionApiService.spec.ts

@@ -0,0 +1,63 @@
+import { SubscriptionInviteResponse } from '../../Response/Subscription/SubscriptionInviteResponse'
+import { SubscriptionServerInterface } from '../../Server/Subscription/SubscriptionServerInterface'
+
+import { SubscriptionApiService } from './SubscriptionApiService'
+
+describe('SubscriptionApiService', () => {
+  let subscriptionServer: SubscriptionServerInterface
+
+  const createService = () => new SubscriptionApiService(subscriptionServer)
+
+  beforeEach(() => {
+    subscriptionServer = {} as jest.Mocked<SubscriptionServerInterface>
+    subscriptionServer.invite = jest.fn().mockReturnValue({
+      data: { success: true, sharedSubscriptionInvitationUuid: '1-2-3' },
+    } as jest.Mocked<SubscriptionInviteResponse>)
+  })
+
+  it('should invite a user', async () => {
+    const response = await createService().invite('test@test.te')
+
+    expect(response).toEqual({
+      data: {
+        success: true,
+        sharedSubscriptionInvitationUuid: '1-2-3',
+      },
+    })
+    expect(subscriptionServer.invite).toHaveBeenCalledWith({
+      api: '20200115',
+      identifier: 'test@test.te',
+    })
+  })
+
+  it('should not invite a user if it is already inviting', async () => {
+    const service = createService()
+    Object.defineProperty(service, 'inviting', {
+      get: () => true,
+    })
+
+    let error = null
+    try {
+      await service.invite('test@test.te')
+    } catch (caughtError) {
+      error = caughtError
+    }
+
+    expect(error).not.toBeNull()
+  })
+
+  it('should not invite a user if the server fails', async () => {
+    subscriptionServer.invite = jest.fn().mockImplementation(() => {
+      throw new Error('Oops')
+    })
+
+    let error = null
+    try {
+      await createService().invite('test@test.te')
+    } catch (caughtError) {
+      error = caughtError
+    }
+
+    expect(error).not.toBeNull()
+  })
+})