Diffblue Cover

What do you like best about the product?

It speeds up my test writing, saves me a lot of time, and even makes the process more enjoyable. I like seeing the tests written for my code.
They are unbiased and can confirm if the behavior is what I expect.
I'd recommend Diffblue Cover to anyone writing code in Java.

What do you dislike about the product?

Primarily, I wish Diffblue supported more languages so I could use it for other applications.

What problems is the product solving and how is that benefiting you?

Writing tests was not enjoyable and often time-consuming, occasionally leading to low-quality tests just to meet the coverage requirements.
With Diffblue, the process is much faster, ensuring higher-quality coverage and more time to focus in more important tasks.

What do you like best about the product?

One of the best things about Diffblue Cover is how much time it saves! It’s honestly so useful in auto-generating unit tests, which otherwise can be super tedious to write by hand. Especially when working with older codebases that don’t have any existing tests, Diffblue just jumps in and handles it, which is a huge relief. Having these tests gives us more confidence that our code changes won’t break anything crucial – definitely helpful for speeding up our workflow too!

What do you dislike about the product?

There are a few things that could be better with Diffblue Cover. Sometimes, the tests it generates aren’t fully comprehensive, so we still have to go in and tweak them ourselves for more complex logic. It’s mostly focused on Java, which can be limiting if you’re in a mixed environment with other languages. And, depending on the project setup, getting it configured can take a bit longer than expected sometimes.

What problems is the product solving and how is that benefiting you?

Diffblue Cover is really helping us keep up with test coverage without wasting loads of time on it. Normally, writing all those tests takes ages, especially for bigger projects or older code. By automating the process, it’s letting us catch issues early on and prevents a lot of potential bugs slipping through. It’s made our development cycles a lot quicker, so we can focus on building new stuff rather than getting bogged down in test writing

What do you like best about the product?

What I like most about Diffblue Cover is, honestly, how much time it saves. It just - takes care of unit tests automatically, which is great because setting those up can be such a time sink. Especially with older code that’s missing tests; it’s a huge help. Plus, it ‘gets’ even the tricky parts of the code, so I don’t have to double-check everything. Basically, it lets me focus on building things instead of getting bogged down in tests.

What do you dislike about the product?

A few things about Diffblue Cover that aren’t perfect - for one, it doesn’t always catch every edge case. Like, sometimes it’ll miss those really specific scenarios you might run into with complex code. Also, the setup can feel a bit clunky at first, especially if you’re working with a big codebase; it’s not exactly plug-and-play. And sure, while it does a lot, it’s still no replacement for a full test suite crafted by someone who knows the ins and outs of the app.

What problems is the product solving and how is that benefiting you?

For me, Diffblue Cover has been huge in dealing with all the legacy code we have here. Since we’re working with such a massive codebase, setting up tests for everything manually would be a nightmare (and probably impossible). Diffblue basically automates that—like, I don’t have to dive into every corner just to get basic test coverage. It also gives me more confidence in making updates because I know there’s at least some safety net in place, which, let’s be real, helps when you’re just starting out in a big company. And since time’s tight, I can focus more on learning and actually building stuff instead of getting stuck doing repetitive testing work.

What do you like best about the product?

As an IT consultant with a fokus on Spring Boot and testing, I am always on the lookout for tools that can enhance my productivity and make automated testing more easy to tackle for team.

Recently, I had the opportunity to integrate Diffblue Cover into my workflow for one project.

Here's what I liked most about Diffblue Cover:

Automatically Generate Tests for Legacy Projects

For brownfield and legacy projects that have little to no test coverage, Diffblue Cover quickly helps to provide a base test coverage for the project. Writing hundred of tests manually for classes you've never seen before is a cumbersome and time-consuming process. With the help of Diffblue Cover, I could easily generate a test-baseline while executing a single command. This is a great benefit to avoid regressions due to untested code.

Simple Test Skeleton Generation

Another major advantage of Diffblue is its capability to generate test skeletons. As Diffblue Cover analyzes the matching production code, it will generate tests for corner cases and all exeuction paths (if-else branches). These tests come with the relevant setup and test data to verify the class under test.

Increased Productivity

Diffblue Cover comes with both an IntelliJ IDEA integration as well as a CLI tool. The IDE integration helped me during daily development to trigger Diffblue's reinforcement learning model to analyze the code and write tests. The integration in the IDE is easy to install and user-friendly. You generate tests with a click on the method you want test for.

For larger codebases and to automate the test generation process, the CLI tool helps to include Diffblue Cover into a pipeline or CI/CD workflow.

What do you dislike about the product?

While my overall experience with Diffblue Cover is positive, there are a few areas where the tool could improve its functionality.

Test Method Naming

One of the areas where Diffblue can improve is in the generation of test method names. The generated names, while functional, often lack the clarity and descriptiveness for test cases.

Clear and descriptive method names are important for maintaining readable and maintainable code. When Diffblue Cover creates mutliple tests for a single method, it uses counter in the test method name to differentiate the tests. A better approach could be to include the actual test corner case in the method name.

Going Beyond Unit Tests

As Diffblue Cover focusses on the unit testing part of Java applications, developers can't fully use the tool on auto-pilot for a covering test suite.

While Spring Boot and Spring Test offer excellent support for sliced testing and integration testing, developers have to consider when a unit test is sufficient and when to write a broader integration test.

The potential danger lies in neclacting integration tests when focussing only on the unit testing part. While this is not an issue of Diffblue Cover per se, developers might be tempted to write less integration test. This highly depends on the context of the class under test.

What problems is the product solving and how is that benefiting you?

Write Java unit tests on scale, help generate test skeletons, generate a test baseline for untested and legacy Java code