LWCIntermediateapisecurityerror-handling
Validate @api object props with deep clone before mutating child state
Real World Scenario
Child LWC mutates @api config object in place causing parent state corruption and subtle re-render loops.
Expected Answer
• Deep clone @api objects on receive before local mutation
• Treat @api as immutable from child perspective
• Parent passes new object reference on intentional update
• Avoid @api side effects in setter triggering parent cascade
• JSON parse stringify clone for plain config objects
• Document @api contract read-only in component README
• Jest test child does not mutate parent passed object reference
Follow-Up Questions & Answers
Click to expand — each follow-up includes a direct, interview-ready answer
Direct answer: Deep clone @api objects on receive before local mutation Also consider: Treat @api as immutable from child perspective In practice: Parent passes new object reference on intentional update Balance speed of delivery with maintainability.
Architect Perspective
Mutating @api props breaks LWC data flow—clone on entry is defensive standard.