export async function readConfigs()

in packages/jest-config/src/index.ts [279:370]
76 lines of code
17 McCabe index (conditional complexity)

export async function readConfigs(
  argv: Config.Argv,
  projectPaths: Array<string>,
): Promise<{
  globalConfig: Config.GlobalConfig;
  configs: Array<Config.ProjectConfig>;
  hasDeprecationWarnings: boolean;
}> {
  let globalConfig;
  let hasDeprecationWarnings;
  let configs: Array<Config.ProjectConfig> = [];
  let projects = projectPaths;
  let configPath: string | null | undefined;

  if (projectPaths.length === 1) {
    const parsedConfig = await readConfig(argv, projects[0]);
    configPath = parsedConfig.configPath;

    hasDeprecationWarnings = parsedConfig.hasDeprecationWarnings;
    globalConfig = parsedConfig.globalConfig;
    configs = [parsedConfig.projectConfig];
    if (globalConfig.projects && globalConfig.projects.length) {
      // Even though we had one project in CLI args, there might be more
      // projects defined in the config.
      // In other words, if this was a single project,
      // and its config has `projects` settings, use that value instead.
      projects = globalConfig.projects;
    }
  }

  if (projects.length > 0) {
    const cwd =
      process.platform === 'win32' ? tryRealpath(process.cwd()) : process.cwd();
    const projectIsCwd = projects[0] === cwd;

    const parsedConfigs = await Promise.all(
      projects
        .filter(root => {
          // Ignore globbed files that cannot be `require`d.
          if (
            typeof root === 'string' &&
            fs.existsSync(root) &&
            !fs.lstatSync(root).isDirectory() &&
            !constants.JEST_CONFIG_EXT_ORDER.some(ext => root.endsWith(ext))
          ) {
            return false;
          }

          return true;
        })
        .map((root, projectIndex) => {
          const projectIsTheOnlyProject =
            projectIndex === 0 && projects.length === 1;
          const skipArgvConfigOption = !(
            projectIsTheOnlyProject && projectIsCwd
          );

          return readConfig(
            argv,
            root,
            skipArgvConfigOption,
            configPath ? path.dirname(configPath) : cwd,
            projectIndex,
            // we wanna skip the warning if this is the "main" project
            projectIsCwd,
          );
        }),
    );

    ensureNoDuplicateConfigs(parsedConfigs, projects);
    configs = parsedConfigs.map(({projectConfig}) => projectConfig);
    if (!hasDeprecationWarnings) {
      hasDeprecationWarnings = parsedConfigs.some(
        ({hasDeprecationWarnings}) => !!hasDeprecationWarnings,
      );
    }
    // If no config was passed initially, use the one from the first project
    if (!globalConfig) {
      globalConfig = parsedConfigs[0].globalConfig;
    }
  }

  if (!globalConfig || !configs.length) {
    throw new Error('jest: No configuration found for any project.');
  }

  return {
    configs,
    globalConfig,
    hasDeprecationWarnings: !!hasDeprecationWarnings,
  };
}