Function packageImportsResolve

lib/internal/modules/esm/resolve.js:696–753

* Resolves the given import name for a package. * @param {string} name - The name of the import to resolve. * @param {string | URL | undefined} base - The base URL to resolve the import from. * @param {Set } conditions - An object containing the import conditions. * @throws {ERR_INVALID_M

(name, base, conditions)

 * @returns {URL} The resolved import URL.
 */
function packageImportsResolve(name, base, conditions) {
  if (name === '#' || StringPrototypeEndsWith(name, '/')) {
    const reason = 'is not a valid internal imports specifier name';
    throw new ERR_INVALID_MODULE_SPECIFIER(name, reason, fileURLToPath(base));
  }
  let packageJSONUrl;
  const packageConfig = packageJsonReader.getPackageScopeConfig(base);
  if (packageConfig.exists) {
    packageJSONUrl = pathToFileURL(packageConfig.pjsonPath);
    const imports = packageConfig.imports;
    if (imports) {
      if (ObjectPrototypeHasOwnProperty(imports, name) &&
          !StringPrototypeIncludes(name, '*')) {
        const resolveResult = resolvePackageTarget(
          packageJSONUrl, imports[name], '', name, base, false, true, false,
          conditions,
        );
        if (resolveResult != null) {
          return resolveResult;
        }
      } else {
        let bestMatch = '';
        let bestMatchSubpath;
        const keys = ObjectGetOwnPropertyNames(imports);
        for (let i = 0; i < keys.length; i++) {
          const key = keys[i];
          const patternIndex = StringPrototypeIndexOf(key, '*');
          if (patternIndex !== -1 &&
              StringPrototypeStartsWith(name,
                                        StringPrototypeSlice(key, 0,
                                                             patternIndex))) {
            const patternTrailer = StringPrototypeSlice(key, patternIndex + 1);
            if (name.length >= key.length &&
                StringPrototypeEndsWith(name, patternTrailer) &&
                patternKeyCompare(bestMatch, key) === 1 &&
                StringPrototypeLastIndexOf(key, '*') === patternIndex) {
              bestMatch = key;
              bestMatchSubpath = StringPrototypeSlice(
                name, patternIndex, name.length - patternTrailer.length);
            }
          }
        }

        if (bestMatch) {
          const target = imports[bestMatch];
          const resolveResult = resolvePackageTarget(packageJSONUrl, target,
                                                     bestMatchSubpath,
                                                     bestMatch, base, true,
                                                     true, false, conditions);
          if (resolveResult != null) {
            return resolveResult;
          }
        }
      }
    }
  }
  throw importNotDefined(name, packageJSONUrl, base);
}