Detecting Kotlin Code Smells with Detekt
Hello everyone! đź‘‹ In this story I will show how to improve your Kotlin codebase with Detekt, a Kotlin Static Analysis Tool.
Detekt will analyze Kotlin code with multiple rule sets and flag the code that breaks any of its rules. Detekt improves the codebase by enforcing rule sets including complexity, naming, performance & potential-bugs among others.
When added to CI (in my case, CircleCI) it will also act as a safety net in case you try to merge code which contains Kotlin code smells.
Before starting: Make sure you have the latest Gradle (4.10.2 right now) in the gradle-wrapper.properties file.
To implement Detekt let’s start by creating a detekt.gradle file in the root of the project.
We then add it to the top level build.gradle under the allprojects section so it is applied to all of our modules & we also add the Detekt plugin under the plugins section.
Next step is to create the default-detekt-config.yml file in the root of the project, use this one. For detailed information about the config file click here.
For existing projects, ignore current issues by uncommenting the baseline line from the detekt.gradle file and running the gradle command detektBaseline.
That’s it! Now we can run this task from gradle:
detektwill analyze the Kotlin code to ensure no rules are broken, it will fail otherwise. Remember to add it to your CI.
Updating Detekt
Updating Detekt means more rules & less false positives. How to do it?
- Update Detekt version from
pluginsin the top level build.gradle & sync. - Generate a new Detekt config with the gradle command
detektGenerateConfigand compare with the existing one. - Turn the new rules on.
- Run the gradle command
detektto ensure your codebase is not breaking any of the new rules (if it is, rundetektBaselineto update your ignored issues).
Check the project below 👇 if you have any doubts. Remember to add Detekt to your CI and to use the baseline feature to ignore existing issues. Detekt is highly configurable, find documentation here.
