Function resolvePackageTarget

lib/internal/modules/esm/resolve.js:482–548

* Resolves the target of a package based on the provided parameters. * @param {string} packageJSONUrl - The URL of the package.json file. * @param {import('internal/modules/esm/package_config.js').PackageTarget} target - The target to resolve. * @param {string} subpath - The subpath to resolve.

(packageJSONUrl, target, subpath, packageSubpath,
                              base, pattern, internal, isPathMap, conditions)

 * @returns {URL | null | undefined} - The resolved target, or null if not found, or undefined if not resolvable.
 */
function resolvePackageTarget(packageJSONUrl, target, subpath, packageSubpath,
                              base, pattern, internal, isPathMap, conditions) {
  if (typeof target === 'string') {
    return resolvePackageTargetString(
      target, subpath, packageSubpath, packageJSONUrl, base, pattern, internal,
      isPathMap, conditions);
  } else if (ArrayIsArray(target)) {
    if (target.length === 0) {
      return null;
    }

    let lastException;
    for (let i = 0; i < target.length; i++) {
      const targetItem = target[i];
      let resolveResult;
      try {
        resolveResult = resolvePackageTarget(
          packageJSONUrl, targetItem, subpath, packageSubpath, base, pattern,
          internal, isPathMap, conditions);
      } catch (e) {
        lastException = e;
        if (e.code === 'ERR_INVALID_PACKAGE_TARGET') {
          continue;
        }
        throw e;
      }
      if (resolveResult === undefined) {
        continue;
      }
      if (resolveResult === null) {
        lastException = null;
        continue;
      }
      return resolveResult;
    }
    if (lastException == null) {
      return lastException;
    }
    throw lastException;
  } else if (typeof target === 'object' && target !== null) {
    const keys = ObjectGetOwnPropertyNames(target);
    for (let i = 0; i < keys.length; i++) {
      const key = keys[i];
      if (isArrayIndex(key)) {
        throw new ERR_INVALID_PACKAGE_CONFIG(
          fileURLToPath(packageJSONUrl), base,
          '"exports" cannot contain numeric property keys.');
      }
    }
    for (let i = 0; i < keys.length; i++) {
      const key = keys[i];
      if (key === 'default' || conditions.has(key)) {
        const conditionalTarget = target[key];
        const resolveResult = resolvePackageTarget(
          packageJSONUrl, conditionalTarget, subpath, packageSubpath, base,
          pattern, internal, isPathMap, conditions);
        if (resolveResult === undefined) { continue; }
        return resolveResult;