Reasoning about a program’s behavior is extremely tricky in the best of circumstances. When you throw in asynchronicity, it is the absolute worst. It’s like your code is trapped in a convoluted time travel movie. You want to perform some operation, but that requires stepping into a time portal and coming out at some indeterminate future date. Who knows what has changed since you’ve been gone? Add a few more asynchronous operations, and your code very quickly becomes a tangled mess of wibbly-wobbly, timey-wimey stuff. Read more on Time and Relative Distance in Source (Code)…
asynchronous
Unit Testing Frontend Network Requests
Unit testing is a great way to help ensure the continuous delivery of working code over a product’s lifecycle. In client-side applications, unit testing data retrieval is especially important since using data from these asynchronous calls is at the core of what most of these apps do.
Unfortunately, asynchronous calls aren’t easy to test. Read more on Unit Testing Frontend Network Requests…
Speeding Up Your JavaScript Test Suite
Having fast tests is important. Slow running tests slow down development, especially if you’re practicing TDD. If tests are too slow to run, some developers may avoid running them altogether. Slow tests will also slow down CI builds, increasing the length of your feedback loop.
While it takes more development time, doing maintenance on your test suite to ensure it continues to run quickly is an important task that any significant project should prioritize. Read more on Speeding Up Your JavaScript Test Suite…
Asynchronous Testing with Protractor’s ControlFlow
Protractor is an end-to-end testing framework for AngularJS applications that uses a real browser, just as a real user would. It is built on top of NodeJS and WebDriverJS and taps into the internals of Angular to know when Angular is done processing and updating bindings.
The joy of Protractor and WebDriverJS is that we can write our tests in a synchronous style, and still have the added benefits of asynchronous code. Read more on Asynchronous Testing with Protractor’s ControlFlow…
Turning Asynchronous Networking Inside-Out
Developing asynchronous networking applications is an interesting problem with unique challenges and no shortage of solutions for, particularly in Python. But the way you’ve traditionally had to write your code to make it work well could leave you with a codebase that, while solid, could be challenging to read or follow.
I’ll take you through a quick introduction to what asynchronous networking is, show you a callback-based asynchronous implementation using the venerable and excellent Twisted, and then finally show you how Python’s new asyncio library uses coroutines to solve the problem in a whole new way.
Easy Asynchronous Operations in iOS with ReactiveCocoa
Dealing with asynchronous operations is a common problem in mobile development. To keep our app’s user interface as fast and responsive as possible, we need to offload network requests, resource loading (e.g., images), bluetooth operations, and file I/O onto a background thread.
Calling one asynchronous routine and responding to its result is a relatively simple matter, but what happens when several different asynchronous operations must be executed in some set order (serialized)? Apple has built in support for queuing asynchronous operations with NSOperationQueue and Grand Central Dispatch, but there’s another solution: using a functional reactive approach with Reactive Cocoa. Read more on Easy Asynchronous Operations in iOS with ReactiveCocoa…