utils.ts

export function isCallable(fn: unknown): fn is (...args: any[]) => any {
  return typeof fn === 'function';
}

export function isNullOrUndefined(value: unknown): value is undefined | null {
  return value === null || value === undefined;
}

export function isEmptyArray(arr: unknown): boolean {
  return Array.isArray(arr) && arr.length === 0;
}

export const isObject = (obj: unknown): obj is Record<string, unknown> =>
  obj !== null && !!obj && typeof obj === 'object' && !Array.isArray(obj);

export function isIndex(value: unknown): value is number {
  return Number(value) >= 0;
}

export function toNumber(value: string): number | string {
  const n = parseFloat(value);

  return isNaN(n) ? value : n;
}

export function merge(target: any, source: any) {
  Object.keys(source).forEach(key => {
    if (isObject(source[key])) {
      if (!target[key]) {
        target[key] = {};
      }

      merge(target[key], source[key]);
      return;
    }

    target[key] = source[key];
  });

  return target;
}