Code Inspections and Intentions
Product Help: Code inspections, Intention actions
UI Guidelines: Inspections
Code inspections analyze code for potential issues, such as errors, inefficiencies, or code smells. Code intentions suggest improvements and refactorings to enhance readability and maintainability.
While inspections focus on detecting problems, intentions provide optional enhancements to improve code structure. Inspections are run on a full PSI tree and report found problems, while intention actions are run only on elements under the cursor.
The code inspections for custom languages use the same API as all other code inspections, based on the LocalInspectionTool class.
The functionality of LocalInspectionTool partially duplicates that of Annotator.
The main differences are:
supports batch analysis of code (through the Code | Inspect Code... action)
the possibility to turn off the inspection (globally or by suppressing them on various levels)
ability to configure the inspection options.
If none of that is required and the analysis only needs to run in the active editor, Annotator provides better performance (because it supports incremental analysis) and more flexibility for highlighting errors.
Examples:
tip
See changes in the order of running highlighting introduced in 2024.1.
A custom language plugin providing many inspections (>100) can register the default PsiElementVisitor for its language in com.intellij.inspection.basicVisitor extension point to optimize processing.
The code intentions for custom languages also use the standard API for intentions. The intention classes need to implement the IntentionAction interface and are registered using the com.intellij.intentionAction extension point.
Examples: