Function addPrototypeProperties

lib/internal/util/inspect.js:970–1023

(ctx, main, obj, recurseTimes, output)

// `output` argument (which is an array). This is intended to highlight user
// defined prototype properties.
function addPrototypeProperties(ctx, main, obj, recurseTimes, output) {
  let depth = 0;
  let keys;
  let keySet;
  do {
    if (depth !== 0 || main === obj) {
      obj = ObjectGetPrototypeOf(obj);
      // Stop as soon as a null prototype is encountered.
      if (obj === null) {
        return;
      }
      // Stop as soon as a built-in object type is detected.
      const descriptor = ObjectGetOwnPropertyDescriptor(obj, 'constructor');
      if (descriptor !== undefined &&
          typeof descriptor.value === 'function' &&
          builtInObjects.has(descriptor.value.name)) {
        return;
      }
    }

    if (depth === 0) {
      keySet = new SafeSet();
    } else {
      ArrayPrototypeForEach(keys, (key) => keySet.add(key));
    }
    // Get all own property names and symbols.
    keys = ReflectOwnKeys(obj);
    ArrayPrototypePush(ctx.seen, main);
    for (const key of keys) {
      // Ignore the `constructor` property and keys that exist on layers above.
      if (key === 'constructor' ||
          ObjectPrototypeHasOwnProperty(main, key) ||
          (depth !== 0 && keySet.has(key))) {
        continue;
      }
      const desc = ObjectGetOwnPropertyDescriptor(obj, key);
      if (typeof desc.value === 'function') {
        continue;
      }
      const value = formatProperty(
        ctx, obj, recurseTimes, key, kObjectType, desc, main);
      if (ctx.colors) {
        // Faint!
        ArrayPrototypePush(output, `\u001b[2m${value}\u001b[22m`);
      } else {
        ArrayPrototypePush(output, value);
      }
    }
    ArrayPrototypePop(ctx.seen);
  // Limit the inspection to up to three prototype layers. Using `recurseTimes`
  // is not a good choice here, because it's as if the properties are declared
  // on the current object from the users perspective.
  } while (++depth !== 3);
}

/** @type {(constructor: string, tag: string, fallback: string, size?: string) => string} */
function getPrefix(constructor, tag, fallback, size = '') {