Dialogflow fulfillment to post to slack

index.js

'use strict';

const SlackBot = require('slackbots');
const channel = '<CHANNEL_TO_POST>';
const bot = new SlackBot({
    token: '<SLACK_BOT_TOKEN>'
});

const functions = require('firebase-functions'); // Cloud Functions for Firebase library
const DialogflowApp = require('actions-on-google').DialogflowApp; // Google Assistant helper library
exports.dialogflowFirebaseFulfillment = functions.https.onRequest((request, response) => {
  console.log('Dialogflow Request headers: ' + JSON.stringify(request.headers));
  console.log('Dialogflow Request body: ' + JSON.stringify(request.body));
  if (request.body.result) {
    processV1Request(request, response);
  } else {
    console.log('Invalid Request');
    return response.status(400).end('Invalid Webhook Request (expecting v1 request)');
  }
});
/*
* Function to handle v1 webhook requests from Dialogflow
*/
function processV1Request (request, response) {
  let action = request.body.result.action; // https://dialogflow.com/docs/actions-and-parameters
  let parameters = request.body.result.parameters; // https://dialogflow.com/docs/actions-and-parameters
  let inputContexts = request.body.result.contexts; // https://dialogflow.com/docs/contexts
  let requestSource = (request.body.originalRequest) ? request.body.originalRequest.source : undefined;
  const googleAssistantRequest = 'google'; // Constant to identify Google Assistant requests
  const app = new DialogflowApp({request: request, response: response});
  // Create handlers for Dialogflow actions as well as a 'default' handler
  const actionHandlers = {
    // Default handler for unknown or undefined actions
    'default': () => {
      const body = request.body.result.parameters.any;
      bot.postMessageToChannel(channel, body, {as_user:true});
      
      const message = 'スラックに' + body + 'とポストしました'; 
      let responseToUser = {
        speech: message, // spoken response
        text: message // displayed response
      };
      sendGoogleResponse(responseToUser);
    }
  };
  // If undefined or unknown action use the default handler
  if (!actionHandlers[action]) {
    action = 'default';
  }
  // Run the proper handler function to handle the request from Dialogflow
  actionHandlers[action]();
    // Function to send correctly formatted Google Assistant responses to Dialogflow which are then sent to the user
  function sendGoogleResponse (responseToUser) {
    if (typeof responseToUser === 'string') {
      app.ask(responseToUser); // Google Assistant response
    } else {
      // If speech or displayText is defined use it to respond
      let googleResponse = app.buildRichResponse().addSimpleResponse({
        speech: responseToUser.speech || responseToUser.displayText,
        displayText: responseToUser.displayText || responseToUser.speech
      });
      // Optional: Overwrite previous response with rich response
      if (responseToUser.googleRichResponse) {
        googleResponse = responseToUser.googleRichResponse;
      }
      // Optional: add contexts (https://dialogflow.com/docs/contexts)
      if (responseToUser.googleOutputContexts) {
        app.setContext(...responseToUser.googleOutputContexts);
      }
      console.log('Response to Dialogflow (AoG): ' + JSON.stringify(googleResponse));
      app.tell(googleResponse); // Send response to Dialogflow and Google Assistant
    }
  }
}