FlexInspect

The PSI is an AST representation of your code corresponding to a source file's structure. In the case of Java code, the PSI reflects the basic blocks of a Java file like package and import statements, class statements, method invocations, and other nodes. FlexInspect uses the PSI tree representation of your code to obtain the list of the code nodes that can be inspected using your inspections.

In IntelliJ IDEA, you can navigate through the PSI using the PSI Viewer tool window. To do this, open a file that you would like to view with the PSI Viewer, and then navigate to Tools | View PSI Structure of Current File.

To create a new .inspection.kts template file, follow the procedure below.

Here's an animation showing you how to create an inspection following the above method.

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The created file already contains code examples and explanations, which you can then use to develop your own inspection.

For example, to check whether a method is a constructor, you can use the isConstructor() PSI method, which is available for each method of a class.

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You can develop your inspection using the template that you've already created. In this example, you can iterate over all methods and use the isConstructor() method to check whether a class has a constructor method. If there is no constructor method, the inspection generates an error showing that a class has no constructor method.

Here's the Kotlin snippet for the NoConstructor.inspection.kts file containing inline comments.

import org.intellij.lang.annotations.Language
 {...}

tip

To debug your inspections, you can add inspection.registerProblem(<psi-element>, "<debug-message>") to the inspection code and view the resultant debug message in your IDE.

After creating the inspection, you can see the compilation status on the toolbar in the upper part of the inspection file. When you change the inspection code, you need to explicitly recompile the inspection using the recompile button in the left part of the toolbar or use the Alt+Shift+Enter (Windows) or ⌥⇧↩ (macOS) shortcut.
You can also open files using the PSI Viewer and review inspection examples.

To see how the new inspection functions on your code, open a file containing a problem the inspection is supposed to highlight.

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note

Before you can run your inspection, you'll first need to select a suitable Qodana linter. For example, for PHP, this will be the Qodana for PHP linter.

note

If your custom inspection conflicts with a Qodana inspection, and you would still like to run it, you can disable the relevant Qodana inspection.

FlexInspect is supported by the default inspection profiles.

To inspect your entire project with the new inspection locally, run Qodana as explained in the Run Qodana locally section.

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To run your custom inspection in a CI pipeline, you can visit the Integration with CI systems section and find the instructions for your specific CI/CD solution. Because your inspection is already contained in the inspections directory of your project, it's already available for inspecting your code.

You can use the inspection name from the id field of the inspection file to disable or enable your custom inspection in the qodana.yaml file.