This is the source code for the EchoMe Lex Chatbot Lambda function

amazon-lex-echobot-lambda-function.js

'use strict';
/**
 * This code sample demonstrates an implementation of the Amazon Lex Code Hook Interface
 * to  echo back what the user says
 * Written by: Dennis Hills
 * Date: Jan 9, 2019
 * Amazon Lex Bot setup requires only a single slot
 * Usage: "repeat after me I am the boss" or "repeat after me the quick brown fox jumped over the lazy dog"
 */

// --------------- Main handler -----------------------
// Route the incoming request based on intent.
// The JSON body of the request is provided in the event slot.
exports.handler = (event, context, callback) => {
    try {
        console.log('Received event:', JSON.stringify(event, null, 2));
        echoBack(event, (response) => callback(null, response));
    } catch (err) {
        callback(err);
    }
};

/*
 * Return echoed text back to user 
 */
function echoBack(intentRequest, callback) {

    // Strip "repeat after me" intent off before responding
    var echoResponse = intentRequest.inputTranscript.toLowerCase().replace("repeat after me", "").trim();
    callback(close(null, 'Fulfilled', { contentType: 'PlainText', content: echoResponse }));
    return;
}

function close(sessionAttributes, fulfillmentState, message, responseCard) {
    return {
        sessionAttributes,
        dialogAction: {
            type: 'Close',
            fulfillmentState,
            message,
            responseCard,
        },
    };
}