refactor(modules): create display, qr modules

- Create display module, move RotatingLinksController into it
- Create qr module, move QrCodeService and assets into it
- Extract QrCodeController from `api/qr` into `modules/qr`
- Inject config, existing inversify dependencies into classes
  wherever possible

src/server/api/links.ts

@@ -1,11 +1,11 @@
 import Express from 'express'
 import { container } from '../util/inversify'
-import { RotatingLinksControllerInterface } from '../controllers/interfaces/RotatingLinksControllerInterface'
+import { RotatingLinksController } from '../modules/display'
 import { DependencyIds } from '../constants'
 
 const router = Express.Router()
 
-const linksController = container.get<RotatingLinksControllerInterface>(
+const linksController = container.get<RotatingLinksController>(
   DependencyIds.linksController,
 )
 

src/server/api/qrcode.ts

@@ -3,26 +3,20 @@ import Joi from '@hapi/joi'
 import { createValidator } from 'express-joi-validation'
 
 import ImageFormat from '../../shared/util/image-format'
-import { ogUrl } from '../config'
-import { QrCodeServiceInterface } from '../services/interfaces/QrCodeServiceInterface'
+import { QrCodeController } from '../modules/qr'
 import { isValidShortUrl } from '../../shared/util/validation'
 import { container } from '../util/inversify'
-import { UrlRepositoryInterface } from '../repositories/interfaces/UrlRepositoryInterface'
 import { DependencyIds } from '../constants'
 
-const urlRepository = container.get<UrlRepositoryInterface>(
-  DependencyIds.urlRepository,
+const qrCodeController = container.get<QrCodeController>(
+  DependencyIds.qrCodeController,
 )
 
 function isValidFormat(format: string): boolean {
   const validFormats = Object.values(ImageFormat) as string[]
   return validFormats.includes(format)
 }
 
-async function shortUrlExists(shortUrl: string): Promise<boolean> {
-  return !!(await urlRepository.findByShortUrl(shortUrl))
-}
-
 const qrCodeRequestSchema = Joi.object({
   url: Joi.string()
     .custom((url: string, helpers) => {
@@ -49,31 +43,7 @@ const validator = createValidator()
 router.get(
   '/',
   validator.query(qrCodeRequestSchema),
-  async (req, res): Promise<void> => {
-    const url = req.query.url as string
-    const format = req.query.format as ImageFormat
-
-    if (!(await shortUrlExists(url))) {
-      res.status(400).send('Short link does not exist')
-      return
-    }
-
-    // Append base url to short link before creating the qr.
-    const goShortLink = `${ogUrl}/${url}`
-
-    const qrCodeService = container.get<QrCodeServiceInterface>(
-      DependencyIds.qrCodeService,
-    )
-
-    // Creates the QR code and sends it to the client.
-    qrCodeService.createGoQrCode(goShortLink, format).then((buffer) => {
-      // Provides callee a proposed filename for image.
-      res.set('Filename', goShortLink)
-      res.contentType(format)
-      res.end(buffer)
-      return
-    })
-  },
+  qrCodeController.createGoQrCode,
 )
 
 module.exports = router

src/server/constants.ts

@@ -29,6 +29,7 @@ export const DependencyIds = {
   urlManagementService: Symbol.for('urlManagementService'),
   userController: Symbol.for('userController'),
   qrCodeService: Symbol.for('qrCodeService'),
+  qrCodeController: Symbol.for('qrCodeController'),
   directorySearchService: Symbol.for('directorySearchService'),
   directoryController: Symbol.for('directoryController'),
   linkStatisticsController: Symbol.for('linkStatisticsController'),
@@ -46,6 +47,8 @@ export const DependencyIds = {
   urlCheckController: Symbol.for('urlCheckController'),
   userMessage: Symbol.for('userMessage'),
   userAnnouncement: Symbol.for('userAnnouncement'),
+  linksToRotate: Symbol.for('linksToRotate'),
+  ogUrl: Symbol.for('ogUrl'),
 }
 
 export const ERROR_404_PATH = '404.error.ejs'

src/server/inversify.config.ts

@@ -7,6 +7,8 @@ import {
   accessEndpoint,
   bucketEndpoint,
   cloudmersiveKey,
+  linksToRotate,
+  ogUrl,
   s3Bucket,
   userAnnouncement,
   userMessage,
@@ -38,14 +40,13 @@ import { StatisticsService } from './modules/statistics/services'
 import { StatisticsController } from './modules/statistics'
 
 import { GaController } from './controllers/GaController'
-import { RotatingLinksController } from './controllers/RotatingLinksController'
+import { RotatingLinksController } from './modules/display/RotatingLinksController'
 import { SentryController } from './modules/sentry/SentryController'
 import { LoginController } from './controllers/LoginController'
 import { AuthService } from './services/AuthService'
 import { LogoutController } from './controllers/LogoutController'
 import { UrlManagementService } from './modules/user/services'
 import { UserController } from './modules/user'
-import { QrCodeService } from './services/QrCodeService'
 import { DirectoryController } from './controllers/DirectoryController'
 import { DirectorySearchService } from './services/DirectorySearchService'
 import { LinkStatisticsController } from './controllers/LinkStatisticsController'
@@ -63,6 +64,9 @@ import {
 } from './modules/threat/services'
 import { FileCheckController, UrlCheckController } from './modules/threat'
 
+import { QrCodeService } from './modules/qr/services'
+import { QrCodeController } from './modules/qr'
+
 function bindIfUnbound<T>(
   dependencyId: symbol,
   impl: { new (...args: any[]): T },
@@ -77,6 +81,8 @@ export default () => {
   container
     .bind(DependencyIds.userAnnouncement)
     .toConstantValue(userAnnouncement)
+  container.bind(DependencyIds.linksToRotate).toConstantValue(linksToRotate)
+  container.bind(DependencyIds.ogUrl).toConstantValue(ogUrl)
 
   bindIfUnbound(DependencyIds.urlRepository, UrlRepository)
   bindIfUnbound(DependencyIds.urlMapper, UrlMapper)
@@ -102,6 +108,7 @@ export default () => {
   bindIfUnbound(DependencyIds.urlManagementService, UrlManagementService)
   bindIfUnbound(DependencyIds.userController, UserController)
   bindIfUnbound(DependencyIds.qrCodeService, QrCodeService)
+  bindIfUnbound(DependencyIds.qrCodeController, QrCodeController)
   bindIfUnbound(DependencyIds.directorySearchService, DirectorySearchService)
   bindIfUnbound(DependencyIds.directoryController, DirectoryController)
   bindIfUnbound(DependencyIds.deviceCheckService, DeviceCheckService)

src/server/modules/display/RotatingLinksController.ts

@@ -0,0 +1,21 @@
+import Express from 'express'
+import { inject, injectable } from 'inversify'
+import { DependencyIds } from '../../constants'
+
+@injectable()
+export class RotatingLinksController {
+  private linksToRotate?: string
+
+  constructor(@inject(DependencyIds.linksToRotate) linksToRotate?: string) {
+    this.linksToRotate = linksToRotate
+  }
+
+  getRotatingLinks: (_: Express.Request, res: Express.Response) => void = (
+    _,
+    res,
+  ) => {
+    res.send(this.linksToRotate)
+  }
+}
+
+export default RotatingLinksController

test/server/controllers/RotatingLinksController.test.ts → src/server/modules/display/__tests__/RotatingLinksController.test.ts

@@ -1,13 +1,14 @@
 import httpMocks from 'node-mocks-http'
-import { RotatingLinksController } from '../../../src/server/controllers/RotatingLinksController'
+import { RotatingLinksController } from '../RotatingLinksController'
 
 describe('RotatingLinksController tests', () => {
+  const linksToRotate = 'testlink1,testlink2,testlink3'
+  const controller = new RotatingLinksController(linksToRotate)
   it('Should return rotating links defined in the application configurations', () => {
-    const controller = new RotatingLinksController()
     const { req, res } = httpMocks.createMocks()
     jest.spyOn(res, 'send')
     controller.getRotatingLinks(req, res)
 
-    expect(res.send).toBeCalledWith('testlink1,testlink2,testlink3')
+    expect(res.send).toBeCalledWith(linksToRotate)
   })
 })

src/server/modules/display/index.ts

@@ -0,0 +1,4 @@
+export {
+  RotatingLinksController,
+  RotatingLinksController as default,
+} from './RotatingLinksController'

src/server/modules/qr/QrCodeController.ts

@@ -0,0 +1,58 @@
+import { Request, Response } from 'express'
+import { inject, injectable } from 'inversify'
+import { UrlRepositoryInterface } from '../../repositories/interfaces/UrlRepositoryInterface'
+
+import ImageFormat from '../../../shared/util/image-format'
+import { DependencyIds } from '../../constants'
+
+import { QrCodeService } from './interfaces'
+
+@injectable()
+export class QrCodeController {
+  private ogUrl: string
+
+  private qrCodeService: QrCodeService
+
+  private urlRepository: UrlRepositoryInterface
+
+  constructor(
+    @inject(DependencyIds.ogUrl) ogUrl: string,
+    @inject(DependencyIds.qrCodeService) qrCodeService: QrCodeService,
+    @inject(DependencyIds.urlRepository) urlRepository: UrlRepositoryInterface,
+  ) {
+    this.ogUrl = ogUrl
+    this.qrCodeService = qrCodeService
+    this.urlRepository = urlRepository
+  }
+
+  private shortUrlExists: (shortUrl: string) => Promise<boolean> = async (
+    shortUrl,
+  ) => {
+    return !!(await this.urlRepository.findByShortUrl(shortUrl))
+  }
+
+  createGoQrCode: (req: Request, res: Response) => Promise<void> = async (
+    req,
+    res,
+  ): Promise<void> => {
+    const url = req.query.url as string
+    const format = req.query.format as ImageFormat
+
+    if (!(await this.shortUrlExists(url))) {
+      res.status(400).send('Short link does not exist')
+      return
+    }
+
+    // Append base url to short link before creating the qr.
+    const goShortLink = `${this.ogUrl}/${url}`
+
+    // Creates the QR code and sends it to the client.
+    const buffer = await this.qrCodeService.createGoQrCode(goShortLink, format)
+    // Provides callee a proposed filename for image.
+    res.set('Filename', goShortLink)
+    res.contentType(format)
+    res.end(buffer)
+  }
+}
+
+export default QrCodeController

src/server/modules/qr/index.ts

@@ -0,0 +1,4 @@
+export {
+  QrCodeController,
+  QrCodeController as default,
+} from './QrCodeController'

src/server/modules/qr/interfaces/QrCodeService.ts

@@ -0,0 +1,7 @@
+import ImageFormat from '../../../../shared/util/image-format'
+
+export interface QrCodeService {
+  createGoQrCode: (url: string, format: ImageFormat) => Promise<Buffer>
+}
+
+export default QrCodeService

src/server/modules/qr/interfaces/index.ts

@@ -0,0 +1 @@
+export { QrCodeService, QrCodeService as default } from './QrCodeService'

src/server/services/QrCodeService/index.ts → src/server/modules/qr/services/QrCodeService.ts

@@ -3,12 +3,12 @@ import { select } from 'd3'
 import fs from 'fs'
 import QRCode from 'qrcode'
 import { resolve } from 'path'
-import util from 'util'
 import sharp from 'sharp'
 import { injectable } from 'inversify'
 
-import ImageFormat from '../../../shared/util/image-format'
-import { QrCodeServiceInterface } from '../interfaces/QrCodeServiceInterface'
+import ImageFormat from '../../../../shared/util/image-format'
+
+import * as interfaces from '../interfaces'
 
 const { JSDOM } = jsdom
 
@@ -18,11 +18,8 @@ export const MARGIN_VERTICAL = 85
 export const FONT_SIZE = 32
 export const LINE_HEIGHT = 1.35
 
-// Convert readFile callback function to promise function.
-const readFile = util.promisify(fs.readFile)
-
 @injectable()
-export class QrCodeService implements QrCodeServiceInterface {
+export class QrCodeService implements interfaces.QrCodeService {
   // Build base QR code string without logo.
   private makeQrCode: (url: string) => Promise<string> = (url) => {
     return QRCode.toString(url, {
@@ -57,8 +54,8 @@ export class QrCodeService implements QrCodeServiceInterface {
     const dom = new JSDOM(`<!DOCTYPE html><body></body>`)
 
     // Read the logo as a string.
-    const filePath = resolve(__dirname, 'assets/qrlogo.svg')
-    const logoSvg = await readFile(filePath, 'utf-8')
+    const filePath = resolve(__dirname, '../assets/qrlogo.svg')
+    const logoSvg = fs.readFileSync(filePath, 'utf-8')
 
     const body = select(dom.window.document.querySelector('body'))
 

src/server/modules/qr/services/__tests__/QrCodeService.test.ts

@@ -0,0 +1,30 @@
+import jsQR from 'jsqr'
+import png from 'upng-js'
+
+import ImageFormat from '../../../../../shared/util/image-format'
+
+import { QrCodeService } from '..'
+
+const testUrl = 'https://github.com/opengovsg/GoGovSG'
+
+describe('GoGovSg QR code', () => {
+  describe('generates accurately', () => {
+    const qrCodeService = new QrCodeService()
+
+    test('png string', async () => {
+      const buffer = (await qrCodeService.createGoQrCode(
+        testUrl,
+        ImageFormat.PNG,
+      )) as Buffer
+      const data = png.decode(buffer)
+      const out = {
+        data: new Uint8ClampedArray(png.toRGBA8(data)[0]),
+        height: data.height,
+        width: data.width,
+      }
+      const code = jsQR(out.data, out.width, out.height)
+      expect(code).not.toBeNull()
+      expect(code!.data).toEqual(testUrl)
+    })
+  })
+})

src/server/modules/qr/services/index.ts

@@ -0,0 +1 @@
+export { QrCodeService, QrCodeService as default } from './QrCodeService'