How to create a bot on Whatsapp?

README.MD

• Video: https://www.youtube.com/watch?v=FBMm7P8f3BI

• Medium: https://medium.com/@sanchezcarlosjr/how-to-create-a-bot-on-whatsapp-476a61ce3c15

• Web: https://sanchezcarlosjr.com/

• Ana email bot: hola@sanchezcarlosjr.com

• Ana whatsapp bot: https://x.sanchezcarlosjr.com/whatsapp

Dialogflow.ts

import * as dialogflow from '@google-cloud/dialogflow';
import { uuid } from 'uuidv4';
import { NaturalProcessorLanguage } from '../domain/NaturalProcessorLanguage';
import * as protos from '@google-cloud/dialogflow/build/protos/protos';

export class Dialogflow implements NaturalProcessorLanguage {
  private responses:
    [protos.google.cloud.dialogflow.v2.IDetectIntentResponse,
      protos.google.cloud.dialogflow.v2.IDetectIntentRequest | undefined, {} | undefined];
  async detectIntent(text: string, sessionId: string = uuid()): Promise<string> {
    if (text.length > 250) {
      return new Promise((resolve) => resolve('Be shorter in your request'));
    }
    const sessionClient = new dialogflow.SessionsClient();
    const sessionPath = sessionClient.projectAgentSessionPath('project-id ', sessionId);
    this.responses = await sessionClient.detectIntent({
      session: sessionPath,
      queryInput: {
        text: {
          text,
          languageCode: 'en-US'
        },
      },
    });
    return this.responses[0].queryResult.fulfillmentText;
  }
  getMedia(): string {
    if (this.responses[0].queryResult.fulfillmentText === 'Listen to how I am!') {
      return 'https://firebasestorage.googleapis.com/v0/b/arsus-production.appspot.com/o/assets%2FWhatsApp%20Ptt%202020-07-17%20at%205.14.18%20PM.ogg?alt=media&token=b0de767c-e6b5-49d8-b916-275244ff3ed6';
    }
    return '';
  }
}

NaturalProcessorLanguage.ts

export interface NaturalProcessorLanguage {
  detectIntent(text: string, sessionId?: string): Promise<string>;
  getMedia(): string;
}

package.json

{
  "name": "arsus-server",
  "scripts": {
    "build": "tsc",
    "start": "npm run shell",
    "test": "npm run test:unit",
    "test:unit": "mocha -r ts-node/register tests/**/*.spec.ts --timeout 100000",
    "test:features": "cucumber-js -p default",
    "deploy": "firebase deploy --only functions"
  },
  "main": "lib/index.js",
  "dependencies": {
    "@google-cloud/dialogflow": "^2.0.0",
    "@google-cloud/vision": "^2.1.0",
    "@sendgrid/mail": "^7.2.0",
    "actions-on-google": "^2.12.0",
    "dialogflow-fulfillment": "^0.6.1",
    "express": "^4.17.1",
    "firebase": "^7.15.1",
    "firebase-admin": "^8.12.1",
    "firebase-functions": "^3.7.0",
    "twilio": "^3.48.0",
    "uuidv4": "^6.1.1"
  },
  "devDependencies": {
    "@firebase/firestore-types": "^1.11.0",
    "@types/actions-on-google": "^2.0.1",
    "@types/chai": "^4.2.11",
    "@types/cucumber": "^6.0.1",
    "@types/express": "^4.17.6",
    "@types/faker": "^4.1.12",
    "@types/jest": "^26.0.0",
    "@types/mocha": "^7.0.2",
    "@types/node": "^14.0.13",
    "@types/request-promise": "^4.1.46",
    "@types/sinon": "^9.0.4",
    "@types/stripe": "^7.13.23",
    "@types/supertest": "^2.0.9",
    "chai": "^4.2.0",
    "chai-as-promised": "^7.1.1",
    "cucumber": "^6.0.5",
    "faker": "^4.1.0",
    "firebase-functions-test": "^0.2.1",
    "mocha": "^8.0.1",
    "sinon": "^9.0.2",
    "supertest": "^4.0.2",
    "ts-jest": "^26.1.0",
    "ts-node": "^8.10.2",
    "tslint": "^6.1.2",
    "typescript": "^3.9.5"
  },
  "engines": {
    "node": "10"
  },
  "private": true
}

SMS.ts

import { https } from 'firebase-functions';
import { Response } from 'express';
import { Dialogflow } from '../../../../contexts/email/infraestructure/Dialogflow';
import * as functions from 'firebase-functions';
import { WhatsappCreator } from '../../../../contexts/blog/bot/application/WhatsappCreator';

export interface BodyTwilio {
  SmsMessageSid: string;
  NumMedia: string;
  SmsSid: string;
  SmsStatus: string;
  Body: string;
  To: string;
  NumSegments: string;
  MessageSid: string;
  AccountSid: string;
  From: string;
  ApiVersion: string;
}

export const SMS = functions
  .runWith({
    timeoutSeconds: 20,
    memory: '2GB'
  })
  .https.onRequest(async (request: https.Request, response: Response) => {
    const body: BodyTwilio  = request.body;
    const whatsappCreator = new WhatsappCreator(new Dialogflow());
    const xml: string = await whatsappCreator.create(body.Body, body.From);
    response.setHeader('Content-Type', 'text/xml');
    return response.send(xml);
  });

tsconfig.json

{
  "compilerOptions": {
    "module": "commonjs",
    "noImplicitReturns": true,
    "noUnusedLocals": true,
    "outDir": "lib",
    "sourceMap": true,
    "strict": true,
    "target": "es2015",
    "strictNullChecks": false,
    "skipLibCheck": true
  },
  "lib": ["esnext.asynciterable", "es2015", "dom"],
  "compileOnSave": true,
  "include": ["src/*"],
  "exclude": ["node_modules", "**/*.spec.ts"]
}

tslint.ts

{
  "extends": ["tslint:recommended", "tslint-config-prettier"],
  "rules": {
    "array-type": false,
    "arrow-parens": false,
    "deprecation": {
      "severity": "warn"
    },
    "import-blacklist": [true, "rxjs/Rx"],
    "max-line-length": [true, 120],
    "member-access": false,
    "member-ordering": [
      true,
      {
        "order": [
          "public-static-field",
          "protected-static-field",
          "private-static-field",
          "public-instance-field",
          "protected-instance-field",
          "private-instance-field",
          "constructor",
          "public-static-method",
          "protected-static-method",
          "private-static-method",
          "public-instance-method",
          "protected-instance-method",
          "private-instance-method"
        ]
      }
    ],
    "interface-name": false,
    "max-classes-per-file": false,
    "no-consecutive-blank-lines": false,
    "no-console": [true, "debug", "time", "timeEnd", "trace"],
    "no-duplicate-variable": [true, "check-parameters"],
    "no-empty": false,
    "no-inferrable-types": [true, "ignore-params"],
    "no-non-null-assertion": true,
    "no-redundant-jsdoc": true,
    "no-switch-case-fall-through": true,
    "no-unnecessary-initializer": true,
    "object-literal-sort-keys": false,
    "quotemark": [true, "single"],
    "typedef": [true, "parameter", "property-declaration"],
    "variable-name": false,
    "no-var-requires": false,
    "object-literal-key-quotes": false,
    "ordered-imports": false,
    "trailing-comma": false,
    "no-conflicting-lifecycle": true,
    "no-output-native": true,
    "directive-selector": [true, "attribute", "app", "camelCase"],
    "component-selector": [true, "element", "page", "app", "kebab-case"],
    "template-banana-in-box": true,
    "template-no-negated-async": true,
    "no-output-on-prefix": true,
    "no-inputs-metadata-property": true,
    "no-outputs-metadata-property": true,
    "no-host-metadata-property": true,
    "no-input-rename": true,
    "no-output-rename": true,
    "use-lifecycle-interface": true,
    "use-pipe-transform-interface": true,
    "component-class-suffix": true,
    "contextual-lifecycle": true,
    "directive-class-suffix": true
  }
}

Whatsapp.spec.ts

import { expect } from 'chai';
import * as mocha from 'mocha';
import { WhatsappCreator } from '../../../src/contexts/blog/bot/application/WhatsappCreator';
import sinon = require('sinon');

mocha.describe('Whatsapp', () => {
  it.only('should return a string', async () => {
    const dialogflow = sinon.createStubInstance(Dialogflow);
    const body = 'ABC';
    dialogflow.detectIntent.returns(new Promise((resolve) => resolve(body)));
    const whatsapp = new WhatsappCreator(dialogflow);
    const response = await whatsapp.create('a');
    const xml = `<?xml version="1.0" encoding="UTF-8"?><Response><Message><Body>${body}</Body></Message></Response>`;
    expect(response).to.equal(xml);
  });
});

WhatsappCreator.ts

import { NaturalProcessorLanguage } from '../../../email/domain/NaturalProcessorLanguage';

const MessagingResponse = require('twilio').twiml.MessagingResponse;

export class WhatsappCreator {
  private twiml = new MessagingResponse();
  private message = this.twiml.message();
  constructor(private naturalProcessorLanguage: NaturalProcessorLanguage) {
  }
  async create(text: string, sessionId: string): Promise<string> {
    const fulfillmentText = await this.naturalProcessorLanguage.detectIntent(text, sessionId);
    this.message.body(fulfillmentText);
    this.setMedia(this.naturalProcessorLanguage.getMedia());
    return this.twiml.toString();
  }
  private setMedia(media: string) {
    if (media) {
      this.message.media(media);
    }
  }
}