Category: JavaScript

How I Fixed: UglifyJs Unexpected token: name (DropIn)

I’ve been trying – in vain – to build the front end for CodeReviewVideos. The issue I have been hitting upon is as follows:

ERROR in app.a2e9a6b7afa471d94d2b.js from UglifyJs
Unexpected token: name (DropIn) [./node_modules/braintree-web-drop-in-react/dist/index.js:109,0][app.a2e9a6b7afa471d94d2b.js:116396,6]

uglifyjs-unexpected-token-name-dropin

As the error states, the issue is with the UglifyJs plugin, which I use in combination with WebPack.

This is a frustrating show-stopping problem. Unless fixed, I couldn’t complete a build.

Here’s what I had in my WebPack prod config:

      new webpack.optimize.UglifyJsPlugin({
        beautify: false,
        mangle: {
          screw_ie8: true,
          keep_fnames: true
        },
        compress: {
          screw_ie8: true,
          warnings: false
        },
        comments: false
      }),

This was only in my WebPack prod config. Therefore I didn’t notice any issue until trying to build for prod.

Now, in truth, I didn’t write the code / config above. I copy / pasted from somewhere else (I forget where) and as it just worked I didn’t pay much attention to it.

When it stopped working, I got sad, then got on to trying to fix it.

My Solution

There’s a bunch of suggested general solutions to this problem. A quick Google will turn up plenty of GitHub issues. Unfortunately none of them were specific to my exact error.

In my case, as best I understand it, the Braintree Web Drop In React should have compiled the dist.js file down to ES5, but is instead, in ES6. I concluded this based on this and this.

dammit-jim-im-a-coder-not-a-webpack-genius
Dammit Jim, I’m a coder not a WebPack genius

Of course, I may be wrong.

Fixing this wasn’t that hard. I just needed to read the docs.

yarn add --dev uglifyjs-webpack-plugin

For me, this added:

"uglifyjs-webpack-plugin": "^1.2.4",

To my devDependencies in package.json.

After which I updated my prod.js WebPack config as follows:

"use strict";

const webpack = require("webpack");
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');

module.exports = function() {
  console.log("BUILDING PRODUCTION");

  return webpackMerge(commonConfig(), {

    plugins: [

      new UglifyJsPlugin({
        test: /\.js($|\?)/i,
        sourceMap: true,
        uglifyOptions: {
          mangle: {
            keep_fnames: true,
          },
          compress: {
            warnings: false,
          },
          output: {
            beautify: false,
          },
        },
      }),

  });
};

I’ve removed everything unrelated to this specific problem.

After which I could get my build to work.

The 2018 Beginners Guide to Back End (JSON API) + Front End Development

It’s been a few weeks in the making, but I am happy now to reveal my latest course here on CodeReviewVideos:

The 2018 Beginners Guide to Back End (JSON API) + Front End Development.

This course will cover building a JSON-based API with the following back-end stacks:

  1. ‘raw’ Symfony 4 (PHP)
  2. Symfony 4 with FOSRESTBundle (PHP)
  3. API Platform (PHP)
  4. Koa JS (JavaScript / node)

Behat will be used to test all of these APIs. One Behat project, four different API implementations – in two different languages (PHP and JS).

We’re going to be covering the happy paths of GET , POST , PUT , (optionally) PATCH , and DELETE.

We’ll also be covering the unhappy paths. Error handling and display is just as important.

Where possible we’re going to try and use just one Behat feature file. It’s not always possible – the various implementations don’t always want to behave identically.

There’s a ton of good stuff covered in these videos. But the back end is only half the battle.

Whether you want to “catch them all”, or you’re working with a dedicated front-end dev, it’s definitely useful to know the basics of both.

With that in mind, you can pick and choose whether to implement the back-end, or front-end, or both.

If you don’t want to implement a back-end yourself, cloning any of the projects and getting an environment up and running is made as easy as possible by way of Docker. But you don’t need to use Docker. You can bring-your-own database, and do it that way, too.

The Front End

Whatever back end you decide to spin up, the front end should play nicely.

We’re going to implement a few different front-ends. The two I’m revealing today are:

  1. ‘raw’ JavaScript
  2. React

I have plans for a few others, but each implementation is a fair amount of work and I don’t want to over promise at this stage. There’s definitely at least two more coming, but let me first get these two on the site 🙂

The raw JavaScript approach aims to show how things were in the ‘bad old days‘. The days before your package manager  would take up ~7gb of your hard disk with its cache  directory.

The benefit of working this way is that there’s really no extra ‘stuff’ to get in the way. We can focus on making requests, and working with responses.

But that said, this is 2018 and the many modern JavaScript libraries and frameworks are fairly awesome. You’ll definitely get a renewed sense of appreciation for how much easier your life is once you’re comfortable using a library like React, after having done things the hard way.

Again, as mentioned we will cover more than just raw JS and React. Currently each implementation is between ten and fifteen videos. Each video takes a couple of hours to write up, and another couple of hours to record on average. I’m going as fast as I can, and will upload and publish as quickly as possible.

You can watch them as they drop right here.

Site Update

Behind the scenes over the past 10 weeks I have been working on integrating CodeReviewVideos with Braintree.

This is to enable support for PayPal.

I tried to create a ticket for everything I could think of ahead of starting development.

And I added a new ticket for any issue I hit during development. I’m not convinced I tracked absolutely everything, but even so I completely underestimated just how much work would be involved in this feature.

Being completely honest, I have never been more envious of Laravel’s Spark offering. For $99 they get Stripe and Braintree integration, and a whole bunch more. Staggering.

There’s a bunch of other new and interesting features in this release.

I’ve taken the opportunity to migrate from Symfony 3 to Symfony 4 for the API. There’s a bunch of new issues that arose during this transition – I hadn’t given it much prior thought, but with the new front controller (public/index.php) totally broke my Behat (app_acceptance.php) setup.

This work is also enabling the next major feature which I will start work on, once PayPal is live. More on that in my next update.

I appreciate that from the outside looking in, there doesn’t seem to have been a great deal of activity on the site over the last few weeks. I can assure you that behind the scenes, there has never been more activity.

Have A Great Weekend

Ok, that’s about it from me for the moment.

As ever, have a great weekend, and happy coding.

p. s. – I would be extremely grateful if you could help me spread the word by clicking here to tweet about the new course.

How I Fixed: Missing Headers on Response in Symfony 3 API

The first time this caught me out, I didn’t feel so bad. The second time – i.e. just now – I knew I had already solved this problem (on a different project), and found my urge to kill rising.

I wanted to POST in some data, and if the resource is successfully created, then the response should contain a link – via a HTTP header – to the newly created resource.

Example PHP / Symfony 3 API controller action code snippet:

    public function postAction(Request $request)
    {
        $form = $this->createForm(MyResourceType::class, null, [
            'csrf_protection' => false,
        ]);

        $form->submit($request->request->all());

        if (!$form->isValid()) {
            return $form;
        }

        $myResource = $form->getData();

        $em = $this->getDoctrine()->getManager();
        $em->persist($myResource);
        $em->flush();

        $routeOptions = [
            'id'      => $myResource->getId(),
            '_format' => $request->get('_format'),
        ];

        return $this->routeRedirectView(
            'get_myresource', 
            $routeOptions, 
            Response::HTTP_CREATED
        );
    }

And from the front end, something like this:

export async function createMyResource(important, info, here) {

  const baseRequestConfig = getBaseRequestConfig();

  const requestConfig = Object.assign({}, baseRequestConfig, {
    method: 'POST',
    body: JSON.stringify({
      important,
      info,
      here
    })
  });

  /* global API_BASE_URL */
  const url = API_BASE_URL + '/my-resource';

  const response = await asyncFetch(url, requestConfig);

  return {
    myResource: {
      id: response.headers.get('Location').replace(`${url}/`, '')
    }
  };
}

Now, the interesting line here – from my point of view, at least – is the final line.

Because this is a newly created resource, I won’t know the ID unless the API tells me. In the Symfony controller action code, the routeRedirectView  will take care of this for me, adding on a Location header pointing to the new resource / record.

I want to grab the Location  from the Headers returned on the Response and by removing the part of the string that contains the URL, I can end up with the new resource ID. It’s brittle, but it works.

Only, sometimes it doesn’t work.

Response
body:(...)
bodyUsed: false
headers: Headers
  __proto__: Headers
ok:true
status:201
statusText:"Created"
type:"cors"
url:"http://api.my-api.dev/app_dev.php/my-resource"
__proto__:Response

Excuse the formatting.

From JavaScript’s point of view, the Headers array is empty.

This leads to an enjoyable error: “Cannot read property ‘replace’ of null”.

Confusingly, however, from the Symfony profiler output from the very same request / response, I can see the header info is there:

Good times.

Ok, so the solution to this is really simple – when you know the answer.

Just expose the Location  header 🙂

# /app/config/config.yml

# Nelmio CORS
nelmio_cors:
    defaults:
        allow_origin:  ["%cors_allow_origin%"]
        allow_methods: ["POST", "PUT", "GET", "DELETE", "OPTIONS"]
        allow_headers: ["content-type", "authorization"]
        expose_headers: ["Location"] # this being the important line
        max_age:       3600
    paths:
        '^/': ~

After that, it all works as expected.