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Since we're working with TypeScript, we can use ts-jest, which conveniently brings Jest along for the ride:
The last thing we'll need to do is render some audio. For this, we'll need to communicate with Google Translate, our text-to-speech provider of choice, and that means we'll need an HTTP client. I generally like node-fetch, so let's go with that:
If you've written JavaScript tests before, particularly with tools like Jest, Jasmine, and Mocha, there's a good chance you've gotten used to writing those tests in a particular way. And if you're like me, you might've raised a bit of an eyebrow when you saw how that first test was written. Here it is again, this time with comments that capture the questions I might've had myself if I were seeing this code for the first time:
From here, there's a bunch more you might think about next: writing more tests to cover the code we just added, exploring some additional flavors of testing in the docs, or having a look at a few examples. You'll find the full source for this walkthrough up on GitHub as well.
From here, there's a bunch more you might think about next: writing more tests to cover the code we just added, exploring some additional flavors of testing in the docs, or having a look at a few examples. You'll find the full source for this walkthrough up on GitHub as well.
Recalling all this stuff did make me wonder, though, what a more modern version of a speaking clock might look like. So in this post, we're going to build one ourselves. We won't use an actual phone number, but we will use Pulumi and AWS --- and because we want to do it right, we'll take a test-driven approach to developing the infrastructure with Jest, the JavaScript testing framework. We'll use TypeScript and Node.js for everything, focus on unit tests, and when we're done, we'll have a single, serverless, browser-friendly HTTPS endpoint that returns an MP3 audio stream that speaks the current time.
If you've written JavaScript tests before, particularly with tools like Jest, Jasmine, and Mocha, there's a good chance you've gotten used to writing those tests in a particular way. And if you're like me, you might've raised a bit of an eyebrow when you saw how that first test was written. Here it is again, this time with comments that capture the questions I might've had myself if I were seeing this code for the first time:
The first thing we'll need is a runtime environment --- someplace to run some server-side JavaScript that can render and deliver an audio file. Until recently, the easiest way to get an HTTP endpoint up and running on AWS has generally been with AWS Lambda and API Gateway, using Lambda to run the requisite code and API Gateway to expose the Lambda to the internet. Pulumi Crosswalk actually makes this really easy, too --- but with the release of AWS Lambda Function URLs this April, we now have another option, one that doesn't need API Gateway at all.