Object Sealing
Object sealing is a JavaScript feature that prevents new properties from being added to an object and marks all existing properties as non-configurable, meaning they cannot be deleted or have their attributes (like enumerable, writable, or configurable) changed. It is part of JavaScript's object integrity mechanisms, along with freezing and preventing extensions, and is implemented using the Object.seal() method. This ensures a controlled state for objects, useful in scenarios where you want to lock down an object's structure while still allowing property values to be modified.
Developers should use object sealing when they need to enforce a fixed set of properties on an object to prevent accidental additions or deletions, such as in configuration objects, API responses, or when implementing immutable-like patterns in applications. It is particularly valuable in large codebases or team environments to reduce bugs and maintain consistency, as it allows property values to be updated (unlike freezing) but restricts structural changes, balancing flexibility with safety.