Solution: Shape Legacy API Responses Without Touching the Source

Solution explanation

• Lines 2–6: We define the legacyUser object that simulates a response from an outdated API.

  • Its keys use old naming conventions (fname, lname).

  • We’ll adapt these keys to modern equivalents without altering this object.

• Lines 9–23: The createApiAdapter() function constructs a Proxy that provides this translation layer.

  • A mapping object defines how modern names map to legacy keys.

  • The handler object contains a get() trap to intercept property access. ...