export function deepMerge()

in src/lib/utils/object.svelte.ts [57:86]

22 lines of code
8 McCabe index (conditional complexity)


export function deepMerge<T extends DeepMergeable, U extends DeepMergeable>(target: T, source: U): T & U {
	const result: DeepMergeable = { ...target };

	for (const key in source) {
		if (Object.prototype.hasOwnProperty.call(source, key)) {
			const sourceValue = source[key];
			const targetValue = result[key];

			// Handle arrays - merge them
			if (Array.isArray(sourceValue)) {
				result[key] = Array.isArray(targetValue) ? [...targetValue, ...sourceValue] : [...sourceValue];
				continue;
			}

			// Handle plain objects (not null, not arrays, not class instances)
			if (isPlainObject(sourceValue)) {
				result[key] =
					Object.prototype.hasOwnProperty.call(result, key) && isPlainObject(result[key])
						? deepMerge(result[key], sourceValue)
						: deepMerge({}, sourceValue);
				continue;
			}

			// Handle primitives and everything else
			result[key] = sourceValue;
		}
	}

	return result as T & U;
}