Building data-driven web apps with Pyramid and SQLAlchemy Transcripts
Chapter: Testing web apps
Lecture: Why write tests (web)
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Our web app is basically built.
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All we have left to do is test and deploy it.
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So, let's talk about testing web applications.
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Now, this is not a chapter on unit testing
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and all of its benefits in general.
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The goal is to focus on testing web applications,
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addressing some of the challenges that we'll see
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that can be hard, of working with web apps,
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in terms of testing, for example,
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how do we, like, set up the web framework around it
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if it depends upon things like pyramids request object.
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And what are some of the techniques we can use
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to take advantage of stuff the web app
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already provides us, like, the URL structure, and so on.
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Let's begin by asking the question, "Why test?"
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Why should we write tests at all?
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Well, your first response is probably,
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"So that we can find our bugs, there are surely
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"bugs in our web app, let's make sure
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"we find them and then get rid of them."
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And that is great, but that's not
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the only reason to write tests.
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These days in modern software development,
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we have a lot of infrastructure in place
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to help with things like continuous deployment,
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and checking code, and verifying that we don't
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step on each other's feet if we're working on a team,
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things like that, and testing for Python web apps
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is really one of the few verifications
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that we have that we can work with.
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Let's suppose that we have continuous integration,
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which is a system like TeamCity or Travis CI
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that looks at our GitHub repository, watches a branch,
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watches for PRs, and when a change comes in,
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it will automatically check it out
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and build our project, and that build
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probably includes running tests, but if we don't have tests,
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that build passing, what does it mean?
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I actually don't know what it means
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in terms of Python, maybe we could
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install the dependencies, register the website?
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That might be about it, because Python doesn't
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even have compiling, so this testing in place means that
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when our automatic builds pass, that actually says something
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about the state of our web app.
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If we want to go farther, and go with continuous
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delivery and automatic deploy our site
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when we put it onto a branch and the build passes,
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then really need some sort of verification with our test.
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So these tests are important foundational items
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for many things that we might do around our project.
