Function protectProperties

packages/jest-util/src/garbage-collection-utils.ts:86–127

(
  value: T,
  properties: Array<keyof T> = [],
  depth = 2,
)

 * while a value larger than 0 means that deeper levels of nesting will be protected as well.
 */
export function protectProperties<T>(
  value: T,
  properties: Array<keyof T> = [],
  depth = 2,
): boolean {
  if (getDeletionMode() === 'off') {
    return false;
  }

  // Reflect.get may cause deprecation warnings, so we disable them temporarily
  const originalEmitWarning = process.emitWarning;

  try {
    // eslint-disable-next-line @typescript-eslint/no-empty-function
    process.emitWarning = () => {};
    if (
      depth >= 0 &&
      canDeleteProperties(value) &&
      !Reflect.has(value, PROTECT_SYMBOL)
    ) {
      const result = Reflect.defineProperty(value, PROTECT_SYMBOL, {
        configurable: true,
        enumerable: false,
        value: properties,
        writable: true,
      });
      for (const key of getProtectedKeys(value, properties)) {
        try {
          const nested = Reflect.get(value, key);
          protectProperties(nested, [], depth - 1);
        } catch {
          // Reflect.get might fail in certain edge-cases
          // Instead of failing the entire process, we will skip the property.
        }
      }
      return result;
    }
    return false;
  } finally {
    process.emitWarning = originalEmitWarning;
  }
}

/**
 * Whether the given value has properties that can be deleted (regardless of protection).