Method resolveDescriptor

sources/Engine.ts:361–422

(descriptor: Descriptor, {allowTags = false, useCache = true}: {allowTags?: boolean, useCache?: boolean} = {})

  }

  async resolveDescriptor(descriptor: Descriptor, {allowTags = false, useCache = true}: {allowTags?: boolean, useCache?: boolean} = {}): Promise<Locator | null> {
    if (!corepackUtils.isSupportedPackageManagerDescriptor(descriptor)) {
      if (process.env.COREPACK_ENABLE_UNSAFE_CUSTOM_URLS !== `1` && isSupportedPackageManager(descriptor.name))
        throw new UsageError(`Illegal use of URL for known package manager. Instead, select a specific version, or set COREPACK_ENABLE_UNSAFE_CUSTOM_URLS=1 in your environment (${descriptor.name}@${descriptor.range})`);

      return {
        name: descriptor.name,
        reference: descriptor.range,
      };
    }

    const definition = this.config.definitions[descriptor.name as SupportedPackageManagers];
    if (typeof definition === `undefined`)
      throw new UsageError(`This package manager (${descriptor.name}) isn't supported by this corepack build`);

    let finalDescriptor = descriptor;
    if (!semverValid(descriptor.range) && !semverValidRange(descriptor.range)) {
      if (!allowTags)
        throw new UsageError(`Packages managers can't be referenced via tags in this context`);

      // We only resolve tags from the latest registry entry
      const ranges = Object.keys(definition.ranges);
      const tagRange = ranges[ranges.length - 1];

      const packageManagerSpec = definition.ranges[tagRange];
      const registry = corepackUtils.getRegistryFromPackageManagerSpec(packageManagerSpec);

      const tags = await corepackUtils.fetchAvailableTags(registry);
      if (!Object.hasOwn(tags, descriptor.range))
        throw new UsageError(`Tag not found (${descriptor.range})`);

      finalDescriptor = {
        name: descriptor.name,
        range: tags[descriptor.range],
      };
    }

    // If a compatible version is already installed, no need to query one
    // from the remote listings
    const cachedVersion = await corepackUtils.findInstalledVersion(folderUtils.getInstallFolder(), finalDescriptor);
    if (cachedVersion !== null && useCache)
      return {name: finalDescriptor.name, reference: cachedVersion};

    // If the user asked for a specific version, no need to request the list of
    // available versions from the registry.
    if (semverValid(finalDescriptor.range))
      return {name: finalDescriptor.name, reference: finalDescriptor.range};

    const versions = await Promise.all(Object.keys(definition.ranges).map(async range => {
      const packageManagerSpec = definition.ranges[range];
      const registry = corepackUtils.getRegistryFromPackageManagerSpec(packageManagerSpec);

      const versions = await corepackUtils.fetchAvailableVersions(registry);
      return versions.filter(version => semverUtils.satisfiesWithPrereleases(version, finalDescriptor.range));
    }));

    const highestVersion = [...new Set(versions.flat())].sort(semverRcompare);
    if (highestVersion.length === 0)