Tackling Flakiness in Automated Testing: Building Reliable and Trustworthy Tests
Tags: testing, beginners, programming, flakiness
Published: 2023-06-15 10:52:57

By nature, we humans crave stability. We love certainty. The same is true in our professional lives, especially when it comes to automated testing. Few things are more frustrating than unreliable, inconsistent, and yes, flaky tests. It's like having a car that only starts half the time — kind of defeats the purpose, right?

So, let's dive into the messy world of flaky tests and find out how we can fight back against these unpredictable beasts.

## Understanding Flaky Tests

Flaky tests are like that friend who agrees to show up to your party and then doesn't. Next day, there they are, ready for coffee. In the test world, they are the tests that sometimes pass, sometimes fail, but not due to bugs in the application. They're a headache, a nightmare even, for any software tester.

And here's why: flaky tests undermine trust in automation. When we can't rely on our tests, we might start ignoring them, and that's a slippery slope towards chaos. So, how can we go about taming this unruly creature?

## Identifying Flaky Tests

The first step towards solving any problem is — you guessed it — recognizing there's a problem. So, put on your detective hat, because it's time to identify the culprits. Look out for tests that produce different results without any significant changes in code. They are your prime suspects.

Once you've singled out these rogue tests, resist the urge to banish them from your test suite. Instead, take the time to understand why they're acting up. It could be due to timing issues, concurrency problems, external dependencies, or a host of other reasons.

## Fixing Flaky Tests

Now, on to the meat of the matter: how do you fix these flaky tests? Here are some strategies that can help.

### 1. Isolate Tests
Each test should be an island, complete and independent. Interdependent tests are a breeding ground for flakiness. If Test B depends on Test A, and something goes wrong with Test A, Test B is affected even if there's nothing inherently wrong with it. So, make sure each test stands alone and can be run independently of others.

### 2. Embrace Wait Times Wisely
Automated tests are speedy, but sometimes they're too speedy for their own good. They might try to interact with an element before it's ready, leading to test failures. So, we need to tell our tests to wait. But here's the trick: we need to use waits wisely. Don't use a hard-coded sleep time that waits for a specified period regardless of the condition. Instead, go for "smart" waits or conditional waits that pause until a specific condition is met.

### 3. Tackle Non-determinism
Randomness in tests? Not a good idea. Ensure your tests are deterministic. That is, given a particular input, the output should always be the same. Randomness in test data might seem like a good idea to cover more ground, but it can also lead to flaky tests. So keep things predictable.

### 4. Keep Tests Small and Focused
Your tests should follow the Goldilocks principle — not too big, not too small, just right. Each test should focus on a single functionality or aspect of the application. The more granular your tests, the less chance of them being flaky.

## The Takeaway
Making your tests reliable and eliminating flakiness isn't a walk in the park. It requires a deep understanding of your tests and constant vigilance. But the payoff is worth it — trust in your automation suite, smoother development process, and ultimately, better software.

So roll up your sleeves, dive into your test suite, and show those flaky tests who's boss. Remember, your tests are there to serve you, not to make your life miserable. With some dedication, you can ensure they do just that.

Happy testing!

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