txho/src/filterObj.ts

Get a Bitcoin transaction as JSON for CLI and node

const recursiveCloneAndFilter = (object, predicate, objectPath = [], knownObjects = []) => {
	if (object && !knownObjects.includes(object) && typeof object === 'object') {
		if (object.constructor && object.constructor.name === 'Object') {
			const currentknownObjects = knownObjects.concat([object])
			const copy = {}
			Object.keys(object).forEach(key => {
				const value = object[key]
				const currentPath = objectPath.concat(key)
				if (predicate(currentPath, value)) {
					copy[key] = recursiveCloneAndFilter(value, predicate, currentPath, currentknownObjects)
				}
			})
			return copy
		} else if (Array.isArray(object)) {
			const copy = []
			object.forEach((value, index) => {
				copy[index] = recursiveCloneAndFilter(value, predicate, objectPath, knownObjects)
			})
			return copy
		}
	}
	return object
}

const arrayStartsWithArray = (a, b) => {
	return (
		b.filter((element, index) => {
			return a[index] !== b[index]
		}).length === 0
	)
}

export default (object, projection) => {
	const defaultPredicate = !Object.values(projection).includes(1)

	return recursiveCloneAndFilter(object, cpath => {
		const filteredPaths = Object.keys(projection).filter(ppathString => {
			const cpathString = cpath.join('.')
			const ppath = ppathString.split('.')
			if (arrayStartsWithArray(ppath, cpath) || arrayStartsWithArray(cpath, ppath)) {
				if (defaultPredicate) {
					return ppathString === cpathString && !projection[ppathString] === defaultPredicate
				}
				return ppathString === cpathString || !projection[ppathString] === defaultPredicate
			}
			return false
		})
		if (filteredPaths.length) {
			return !defaultPredicate
		}
		return defaultPredicate
	})
}