Add SendGrid notification service

example.env

@@ -39,3 +39,6 @@ IS_CROSS_SITE=false
 # e.g. /api
 
 SIMPLE_COMMENT_API_URL=/.netlify/functions
+
+# NOTIFICATION_SERVICE_API_KEY is optional, but if there is a notification service, this is the associated API key
+# NOTIFICATION_SERVICE_API_KEY=some-optional-api-key

package.json

@@ -61,7 +61,7 @@
     "http-server": "^14.1.0",
     "jest": "29.6.1",
     "jest-environment-jsdom": "^29.6.1",
-    "jest-environment-node": "^29.6.1",
+    "jest-environment-node": "^29.7.0",
     "jsonwebtoken": "^9.0.1",
     "merge": "^2.1.1",
     "mini-css-extract-plugin": "^2.7.6",

src/lib/AbstractNotificationService.ts

@@ -0,0 +1,10 @@
+import { Success, Error } from "./simple-comment-types"
+
+export abstract class AbstractNotificationService {
+  /**
+   * Send notification to moderators
+   */
+  abstract notifyModerators: (
+    message: string
+  ) => Promise<Success | Error> | void
+}

src/lib/MongodbService.ts

@@ -76,6 +76,7 @@ import {
 import { comparePassword, getAuthToken, hashPassword } from "./crypt"
 import * as jwt from "jsonwebtoken"
 import { isGuestId, isValidResult } from "./shared-utilities"
+import { AbstractNotificationService } from "./AbstractNotificationService"
 
 if (process.env.SIMPLE_COMMENT_MODERATOR_PASSWORD === undefined)
   throw "SIMPLE_COMMENT_MODERATOR_PASSWORD is not set in environmental variables"
@@ -97,6 +98,7 @@ export class MongodbService extends AbstractDbService {
   private _db: Db
   readonly _connectionString: string
   readonly _dbName: string
+  readonly _notificationService?: AbstractNotificationService
 
   getClient = async () => {
     if (this._client) {
@@ -114,10 +116,15 @@ export class MongodbService extends AbstractDbService {
     return this._db
   }
 
-  constructor(connectionString: string, dbName: string) {
+  constructor(
+    connectionString: string,
+    dbName: string,
+    notificationService?: AbstractNotificationService
+  ) {
     super()
     this._connectionString = connectionString
     this._dbName = dbName
+    this._notificationService = notificationService
   }
 
   /**
@@ -599,6 +606,13 @@ export class MongodbService extends AbstractDbService {
           body: "Database insertion error",
         }
       }
+
+      if (this._notificationService) {
+        this._notificationService.notifyModerators(
+          `New comment posted by ${authUser.name} (${authUser.email})`
+        )
+      }
+
       return {
         statusCode: 201,
         body: { ...insertComment, user: adminSafeUser },

src/lib/NoOpNotificationService.ts

@@ -0,0 +1,7 @@
+import { AbstractNotificationService } from "./AbstractNotificationService"
+
+export class NoOpNotificationService extends AbstractNotificationService {
+  notifyModerators = (message: string): void => {
+    console.info(`NoOpNotificationService: ${message}`)
+  }
+}

src/lib/SendGridNotificationService.ts

@@ -0,0 +1,62 @@
+import { AbstractNotificationService } from "./AbstractNotificationService"
+import { Error, Success } from "./simple-comment-types"
+import { MailService } from "@sendgrid/mail"
+import { config as dotEnvConfig } from "dotenv"
+dotEnvConfig()
+
+const _sendGridApiKey = process.env.NOTIFICATION_SERVICE_API_KEY
+
+const _moderatorContactEmails = process.env
+  .SIMPLE_COMMENT_MODERATOR_CONTACT_EMAIL
+  ? process.env.SIMPLE_COMMENT_MODERATOR_CONTACT_EMAIL.split(",")
+  : undefined
+
+export class SendGridNotificationService extends AbstractNotificationService {
+  private readonly _mailService: MailService
+  private readonly _moderatorContactEmails: string[]
+  private readonly _sendGridApiKey: string
+
+  constructor(
+    mailService: MailService,
+    sendGridApiKey?: string,
+    moderatorContactEmails?: string[]
+  ) {
+    super()
+
+    const apiKey = sendGridApiKey ?? _sendGridApiKey
+    if (apiKey === undefined)
+      throw "NOTIFICATION_SERVICE_API_KEY is not set in environmental variables"
+    this._sendGridApiKey = apiKey
+
+    const emails = moderatorContactEmails ?? _moderatorContactEmails
+
+    if (emails === undefined || emails.length === 0)
+      throw `SIMPLE_COMMENT_MODERATOR_CONTACT_EMAIL is not set in environmental variables`
+
+    this._moderatorContactEmails = emails
+    mailService.setApiKey(this._sendGridApiKey)
+    this._mailService = mailService
+  }
+
+  notifyModerators = async (body: string): Promise<Error | Success> => {
+    const messages = this._moderatorContactEmails.map(email => ({
+      to: email,
+      from: "[email protected]", // Sender's email address
+      subject: "Simple Comment Notification",
+      text: `${body}`,
+    }))
+
+    const sendPromises = messages.map(message =>
+      this._mailService.send(message)
+    )
+    const sendResults = await Promise.race(sendPromises)
+
+    if (sendResults[0]?.statusCode !== 202) {
+      const { statusCode, body } = sendResults[0]
+      const resultsBody = JSON.stringify(body)
+      return { statusCode, body: resultsBody }
+    } else {
+      return { statusCode: 202, body: "Emails sent successfully" }
+    }
+  }
+}

src/tests/backend/SendGridNotificationService.test.ts

@@ -0,0 +1,129 @@
+import { SendGridNotificationService } from "../../lib/SendGridNotificationService"
+import { ClientResponse, MailService } from "@sendgrid/mail"
+
+jest.mock("dotenv", () => ({
+  config: jest.fn(() => {
+    process.env.SIMPLE_COMMENT_MODERATOR_CONTACT_EMAIL =
+      "[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected]"
+
+    process.env.NOTIFICATION_SERVICE_API_KEY = "SG.from.test.env"
+  }),
+}))
+
+describe("SendGridNotificationService", () => {
+  let sendGridNotificationService: SendGridNotificationService
+  let mailServiceMock: jest.Mocked<MailService>
+
+  const moderatorContactEmails = ["a1@example,com", "[email protected]"]
+  const sendGridTestApiKey = "SG.test"
+
+  const originalEnv = process.env
+
+  beforeEach(() => {
+    jest.resetModules()
+    mailServiceMock = {
+      setApiKey: jest.fn(),
+      send: jest.fn(),
+    } as unknown as jest.Mocked<MailService>
+
+    sendGridNotificationService = new SendGridNotificationService(
+      mailServiceMock,
+      sendGridTestApiKey,
+      moderatorContactEmails
+    )
+  })
+
+  afterEach(() => {
+    process.env = originalEnv
+  })
+
+  it("should set API key", async () => {
+    expect(mailServiceMock.setApiKey).toHaveBeenCalledWith(sendGridTestApiKey)
+  })
+
+  it("should use environmental variable for API key", async () => {
+    new SendGridNotificationService(mailServiceMock)
+    expect(mailServiceMock.setApiKey).toHaveBeenCalledWith("SG.from.test.env")
+  })
+
+  it("should handle email sending failure", async () => {
+    const body = "Test message"
+    const mockErrorResponse: ClientResponse = {
+      statusCode: 500,
+      body: {},
+      headers: undefined,
+    }
+
+    mailServiceMock.send.mockResolvedValueOnce([mockErrorResponse, {}])
+
+    const result = await sendGridNotificationService.notifyModerators(body)
+
+    expect(mailServiceMock.setApiKey).toHaveBeenCalledWith(sendGridTestApiKey)
+    expect(mailServiceMock.send).toHaveBeenCalledTimes(
+      moderatorContactEmails.length
+    )
+    expect(result.statusCode).toEqual(mockErrorResponse.statusCode)
+  })
+
+  it("should throw given empty moderator contact emails", async () => {
+    expect(
+      () =>
+        new SendGridNotificationService(mailServiceMock, sendGridTestApiKey, [])
+    ).toThrowError(
+      "SIMPLE_COMMENT_MODERATOR_CONTACT_EMAIL is not set in environmental variables"
+    )
+  })
+
+  it("should throw given undefined moderator contact emails", async () => {
+    expect(
+      () =>
+        new SendGridNotificationService(mailServiceMock, sendGridTestApiKey, [])
+    ).toThrowError(
+      "SIMPLE_COMMENT_MODERATOR_CONTACT_EMAIL is not set in environmental variables"
+    )
+  })
+
+  it("should send notification to moderators", async () => {
+    const body = "Test message"
+    const clientResponse = {
+      statusCode: 202,
+      body: {},
+      headers: undefined,
+    }
+    const mockResponse: [ClientResponse, object] = [clientResponse, {}]
+
+    mailServiceMock.send.mockResolvedValueOnce(mockResponse)
+
+    const result = await sendGridNotificationService.notifyModerators(body)
+
+    expect(mailServiceMock.setApiKey).toHaveBeenCalledWith(sendGridTestApiKey)
+    expect(mailServiceMock.send).toHaveBeenCalledTimes(
+      moderatorContactEmails.length
+    )
+    expect(result.statusCode).toEqual(202)
+  })
+
+  it("should send mulitple emails given comma-separated SIMPLE_COMMENT_MODERATOR_CONTACT_EMAIL", async () => {
+    const body = "Test message"
+    const clientResponse = {
+      statusCode: 202,
+      body: {},
+      headers: undefined,
+    }
+    const mockResponse: [ClientResponse, object] = [clientResponse, {}]
+
+    mailServiceMock.send.mockResolvedValue(mockResponse)
+
+    const service = new SendGridNotificationService(
+      mailServiceMock,
+      sendGridTestApiKey
+    )
+    const result = await service.notifyModerators(body)
+
+    expect(mailServiceMock.setApiKey).toHaveBeenCalledWith(sendGridTestApiKey)
+    expect(mailServiceMock.send).toHaveBeenCalledTimes(10)
+    expect(result.statusCode).toEqual(202)
+  })
+
+  // Add more test cases as needed
+})