findMissingKeys.ts

// @see https://gist.github.com/employee451/938ae007cddd9733b64acb9a958428bd
import { getNestedObjectKeyNames } from '@shared/helpers/getNestedObjectKeyNames'

type MissingKeyResult = {
	/** The index of the object that has the missing key */
	missingKeyObject: number
	/** The index of the object where the missing key comes from */
	missingKeyOrigin: number
	/** Name of the key that is missing */
	keyName: string
}

/**
 * Finds missing keys between any number of objects. If one of the objects has a key that is missing in one or more of the other objects,
 * all instances where it is missing will be added to the missing key result.
 * @param objects
 */
export const findMissingKeys = (
	...objects: Record<string, any>[]
): MissingKeyResult[] => {
	if (objects.length === 0) {
		return []
	}

	const missingKeys: MissingKeyResult[] = []

	const addMissingKey = (key: MissingKeyResult) => {
		// Prevent duplicate results
		if (
			!missingKeys.some(
				({ missingKeyObject, missingKeyOrigin, keyName }) =>
					missingKeyObject === key.missingKeyObject &&
					missingKeyOrigin === key.missingKeyOrigin &&
					keyName === key.keyName
			)
		) {
			missingKeys.push(key)
		}
	}

	// Loop through each object and compare the keys of all other objects to this one
	objects.forEach((currentObject, currentObjectIndex) => {
		const keyNames = getNestedObjectKeyNames(currentObject)

		// Go through each object and check that it has every key
		objects.forEach((object, index) => {
			const nestedKeys = getNestedObjectKeyNames(object)
			const missingKeys = keyNames.filter((key) => !nestedKeys.includes(key))
			missingKeys.forEach((key) =>
				addMissingKey({
					missingKeyObject: index,
					missingKeyOrigin: currentObjectIndex,
					keyName: key,
				})
			)
		})
	})

	return missingKeys
}