alexaworld-skilldebugger/lib/SkillDebugger.js

Debug nodejs alexa skills on your local development environment.

// Copyright 2017, Peter Ullrich. dotup IT solutions
// https://developer.amazon.com/de/blogs/alexa/post/Tx24Z2QZP5RRTG1/new-alexa-technical-tutorial-debugging-aws-lambda-code-locally

module.exports = {
	config: {
		appId: '',
		roleArn: '',
		region: 'eu-west-1'
	},
	roleSessionName: 'LocalDebugSession',
	skillHandler: null,
	skillRequestBody: null,
	debug: function (request) {

		var AWS = require('aws-sdk');
		var self = this;

		if (self.config.appId === '')
			throw new Error("missing appId");

		if (self.config.roleArn === '')
			throw new Error("missing roleArn");

		if (self.skillHandler === null)
			throw new Error("missing skillHandler");

		if (self.skillRequestBody === null) {
			throw new Error("missing skillRequestBody");
		}

		function context() {
			if (self.skillRequestBody.context === null)
				return null;
			var context = self.skillRequestBody.context;
			context.done = function (error, result) {
				console.log('context.done');
				console.log(error);
				console.log(result);
				process.exit();
			}
			context.succeed = function (result) {
				console.log('context.succeed');
				console.log(result);
				process.exit();
			}
			context.fail = function (error) {
				console.log('context.fail');
				console.log(error);
				process.exit();
			}
			return context;
		}

		AWS.config.region = self.config.region;
		var sts = new AWS.STS();
		sts.assumeRole({
			RoleArn: self.config.roleArn,
			RoleSessionName: self.roleSessionName
		}, function (err, data) {
			if (err) { // an error occurred
				console.log('Cannot assume role');
				console.log(err, err.stack);
			} else { // successful response
				AWS.config.update({
					accessKeyId: data.Credentials.AccessKeyId,
					secretAccessKey: data.Credentials.SecretAccessKey,
					sessionToken: data.Credentials.sessionToken
				});
				var Module = require('module');
				var originalRequire = Module.prototype.require;
				Module.prototype.require = function () {
					if (arguments[0] === 'aws-sdk') {
						return AWS;
					} else {
						return originalRequire.apply(this, arguments);
					}
				};

				var prepareBody = function (body) {
					if (body.session === null)
						return body;
					body.session.application.applicationId = self.config.appId;
					body.context.System.application.applicationId = self.config.appId;
					return body;
				}

				var lambda = self.skillHandler;
				var event = prepareBody(self.skillRequestBody);
				lambda.handler(event, context());
			}
		});
	}
}