Data Validation automation

Choose the validator

• Override UObject::IsDataValid when the rule belongs to a custom asset/class and may need private or protected data.
• Derive UEditorValidatorBase when a validator should cover existing engine classes, several classes, or project-wide policy.

For UEditorValidatorBase, implement CanValidateAsset narrowly and call AssetPasses or AssetFails on every ValidateLoadedAsset execution path. Make messages actionable.

C++ and Blueprint validators are discovered at editor startup. Python validators must register with UEditorValidatorSubsystem.AddValidator. The command-line Data Validation path runs C++ rules by default; do not assume editor-registered Blueprint/Python rules ran in CI without proving the configured extension.

Run surfaces

• One/many assets: Asset Actions > Validate Assets.
• Assets plus dependencies: Validate Assets and Dependencies.
• Folder: Validate Assets in Folder.
• Project: Tools > Validate Data.
• CI: UnrealEditor-Cmd.exe Project.uproject -run=DataValidation.

Design rules

Use fast local validators on save. Put slow global uniqueness, dependency-cycle, budget, and cross-asset relationship checks in an explicit full-project/CI stage.

An error message should contain:

asset path | field/rule | received value | expected condition | repair action

Distinguish Invalid from Not Validated. Unsupported assets should be skipped explicitly, not reported as passed. Treat warnings and errors according to a documented build policy.

Validate the validator

Create fixtures that should pass, warn, and fail. Confirm interactive save, Content Browser, project-wide validation, and commandlet behavior. A validator that only runs in one surface is not yet a reliable gate.