AST’s and JavaScript: Write Code that Writes Code

The adoption of abstract syntax trees in JavaScript has led to an explosion in tooling that has changed the landscape for developers.  The usage of ASTs allows JavaScript developers to better identify potential bugs before executing their code, as well as ensuring a consistent code quality across a codebase.  Their use in build tools has changed how we write our JavaScript applications by not only letting us target future specifications of the JavaScript language but also to compile non-spec compliant syntax (e.g. JSX) to JavaScript for use in the browser.  And by leveraging this data structure, developers can have 100% confidence in updating thousands of JavaScript files using an AST-based script by leveraging codemods.

While these tools carry a ton of power and potential, the use of code modification via AST manipulation scares off many developers.  The name itself will cause your average developer to scratch his head and proclaim, “Well, I’m not a Computer Science major so I don’t think a tool like that is for me.” However, given the current tooling available, AST manipulation is very approachable. [Read more…]

Start Training on a New System by Describing the End Product

As a contractor, I am often thrown into huge code bases with just a list of instructions for environment setup and not much else.

The bummer is that for complex software systems, a list of setup instructions is of hardly any use without understanding the expected end product of the environment you are putting together.

I often wish I also had a list of things I was allowed to do as a new contractor / employee, but this is probably a discussion for another time.

When I buy a Lego set, I bought it based on what the final constructed product looked like on the front of the box.

As you are putting together the Lego set, don’t you sometimes find yourself referring to the cool picture on the front of the box as a general reference and motivator?

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Be Rational—Delete That Code!


In a previous blog post, I brought up the concept of fighting the urge to rewrite code, and instead shift to refactoring code a step at a time until it takes on the features and characteristics that the business needs. Rewriting the code should only be considered a last ditch option. All that said, you will inevitably hit scenarios where you can delete whole swaths of your hard fought code:

  • Refactoring – As you are refactoring code, you will inevitably hit the bottom of the refactoring stack and are now are able to delete whole chunks of code that are no longer needed.
  • Dead End – While coding up a feature, you have found out that the track you have taken is a dead end. There is a need to wipe out all that code and start over on a different path.
  • Fully Supported Third-Party Replacement – Whole chunks of your past work should be replaced by new frameworks and/or third party components.
  • Long Gone Business Requirements – A feature that you poured years into is just no longer needed, and the expense of supporting it is adding up, so it needs to be removed. Nobody learned this lesson more than the Microsoft Internet Explorer team when they started work on the Edge browser (nee Project Spartan)

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You Don’t Need to Rewrite to Move Forward

The story you are about to read is mostly true. The names have been completely omitted to protect the innocent. It is extracted from the caffeine addled brain of an old-school software engineer. Take from it what lessons you wish.

As software engineers we always seem to want to rewrite something. There is an immense sense of freedom that comes from clicking: File –> New Project…

The next time you have the rewrite urge, think instead on how you can execute an incremental improvement to the code without rewriting. I would submit that if you think that a rewrite would be just ‘one step’ and ‘super easy’, it really isn’t. Factors, actors, capital, and time on a scale you never dreamed of will enter into your rewrite effort eventually.

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Browser-less Unit Testing your React/Redux Code with Mocha, Chai, and Enzyme

A lot of JavaScript applications out there require having a browser available to run your unit tests.  For years it seemed like the de-facto configuration for unit testing was some combination of Karma, PhantomJS, and either QUnit or Jasmine.  While I think that there is definitely value in making sure that your application runs properly in a browser, given that that is how your users will interact with it, my personal opinion is that the majority of your test suite should be able to be run outside of a browser environment.  This article will describe what Enzyme brings to the table in terms of unit testing your React/Redux code without needing a browser.

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Vue.js – The Next Library for Angular 1 Developers

Angular is the most successful JavaScript framework ever. I cannot back this up with any numbers, but based on my experience as a developer over the past few years, it is everywhere. It is truly a complete framework, and it’s no wonder why it has achieved so much success in the industry. However, like all technology, it is quickly becoming dated, and new options have entered the fold.

Libraries like React and Angular 2+ have learned from their predecessors and employ strategies and optimizations that result in less code bloat and better performance.  These new-age frameworks also leverage bleeding edge development tools such as Webpack and Babel, which allow developers to utilize future standards (and non-standards) of the JavaScript language, resulting in increased productivity and cleaner code.

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Practical Get Started With Swift

Recently, I had to get started (fast) with Swift on a series of existing iOS projects. I would classify myself as being able to get to fourth gear in a Honda Accord with a manual transmission when it comes to using and applying Swift. I look forward to the day when my Swift knowledge is equivalent to running full out on the Nurburgring in a Bugati Veyron.

My background is C, C++, C#, Objective-C, with a side of JavaScript along the way.

I will never admit to any classic Visual Basic, or VB.NET, code ever being typed by my fingers, ever!

When it comes to learning a new language, I find myself in ‘Use it or lose it’ mode. Learning Swift comes very naturally if you have a concrete task which allows you to add a feature, or refactor an existing iOS project, with brand new Swift code.

I found that becoming proficient with Swift was very easy given the general C language progression in my career. In very short order, I was able to do almost all the tasks in Swift that I would normally do in Objective-C against the CocoaTouch / UIKit API surface. More advanced Swift language constructs exist, which I have barely touched, and hope to be able to learn and apply some day—I am looking at you, protocol extensions and generics.

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Using Aurelia’s Dependency Injection Library In Non-Aurelia App, Part 2

In my last post, we looked at Aurelia’s dependency injection library and how you might be able to use it as a standalone library in your vanilla JavaScript application.  Now, however, I want to take a look at how you might be able to wire it into your React application, and then finally how you might hook it into React/Redux application.

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Adding Amazon Alexa Voice Services to Your iOS App with Swift

Major thanks to the MacLexa project out on Github for providing motivation, source code, and a great starting place for this blog post.


Amazon Echo is an always listening device which acts as an always available assistant. Thanks to the deep integrations that the Amazon Echo has to online services you can issue a wide variety of questions and commands via voice and get real world responses.

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Using Aurelia’s Dependency Injection Library In Non-Aurelia App, Part 1

If you are anything like me then you like to try to keep your code loosely coupled, even your JavaScript code.  The ES2015 module spec helped solve a lot of issues with dependency management in JavaScript apps, but it did not really do anything to prevent having code that is tightly coupled to the specific imports. When Aurelia was originally announced, one of the things that first caught my eye was that it included a dependency injection library that was designed to be standalone so you could use it even if you were not including the rest of the Aurelia framework.  Now that Aurelia has had some time to mature, I decided to see how exactly it might look to use the dependency injection library in a variety of non-Aurelia applications.

In this two-part blog series, I will unpack a few basics about the library itself, and then show how it might be used in three different apps: a vanilla JavaScript app, a React app, and then a React app that uses Redux for its state management.

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