Extract Updated Fields

extractUpdatedFields

The extractUpdatedFields function recursively compares an updated object with a base object and returns a new object containing only the fields whose values have changed.

Function Signature

function extractUpdatedFields<T extends GenericObject>(
  baseObject: T,
  updatedObject: FlattenPartial<T>
): FlattenPartial<T>

Parameters

• baseObject (T): The original reference object.
• updatedObject (FlattenPartial<T>): An object containing potential updates for fields of the base object.

Return Value

• FlattenPartial<T>: A new object containing only the properties that have changed values.

Example Usage

Notes

• This function does not detect newly added keys (use extractNewFields or extractUpdatedAndNewFields for that).
• Arrays are treated as atomic values; their items are not recursively diffed.
• Returns a new object without mutating either input.

Types

FlattenPartial<T>

type FlattenPartial<T> = Partial<{ [K in keyof T]: T[K] }>;