Function baseMergeValue

src/utils.ts:44–83

(target: Record<string, any>, source: Record<string, any>, key: string, customizer?: (a: any, b: any, key: string) => any)

}

function baseMergeValue(target: Record<string, any>, source: Record<string, any>, key: string, customizer?: (a: any, b: any, key: string) => any): void {
  const srcValue = source[key];
  const objValue = target[key];

  if (customizer) {
    const customResult = customizer(objValue, srcValue, key);
    if (customResult !== undefined) {
      target[key] = customResult;
      return;
    }
  }

  if (srcValue === undefined) {
    return;
  }

  if (isPlainObject(srcValue)) {
    if (isPlainObject(objValue)) {
      for (const k of Object.keys(srcValue)) {
        baseMergeValue(objValue as Record<string, any>, srcValue as Record<string, any>, k, customizer);
      }
    } else {
      target[key] = merge({}, srcValue);
    }
  } else if (Array.isArray(srcValue)) {
    if (Array.isArray(objValue)) {
      for (let i = 0; i < srcValue.length; i++) {
        if (isPlainObject(srcValue[i]) && isPlainObject(objValue[i])) {
          merge(objValue[i], srcValue[i]);
        } else if (srcValue[i] !== undefined) {
          objValue[i] = srcValue[i];
        }
      }
    } else {
      target[key] = srcValue.slice();
    }
  } else {
    target[key] = srcValue;
  }
}

export function defaults<T>(target: T, ...sources: any[]): T {
  for (const source of sources) {