function getPackageInfo()

in packages/create-react-app/createReactApp.js [683:741]

• 54 lines of code
• 6 McCabe index (conditional complexity)

function getPackageInfo(installPackage) {
  if (installPackage.match(/^.+\.(tgz|tar\.gz)$/)) {
    return getTemporaryDirectory()
      .then(obj => {
        let stream;
        if (/^http/.test(installPackage)) {
          stream = hyperquest(installPackage);
        } else {
          stream = fs.createReadStream(installPackage);
        }
        return extractStream(stream, obj.tmpdir).then(() => obj);
      })
      .then(obj => {
        const { name, version } = require(path.join(
          obj.tmpdir,
          'package.json'
        ));
        obj.cleanup();
        return { name, version };
      })
      .catch(err => {
        // The package name could be with or without semver version, e.g. react-scripts-0.2.0-alpha.1.tgz
        // However, this function returns package name only without semver version.
        console.log(
          `Could not extract the package name from the archive: ${err.message}`
        );
        const assumedProjectName = installPackage.match(
          /^.+\/(.+?)(?:-\d+.+)?\.(tgz|tar\.gz)$/
        )[1];
        console.log(
          `Based on the filename, assuming it is "${chalk.cyan(
            assumedProjectName
          )}"`
        );
        return Promise.resolve({ name: assumedProjectName });
      });
  } else if (installPackage.startsWith('git+')) {
    // Pull package name out of git urls e.g:
    // git+https://github.com/mycompany/react-scripts.git
    // git+ssh://github.com/mycompany/react-scripts.git#v1.2.3
    return Promise.resolve({
      name: installPackage.match(/([^/]+)\.git(#.*)?$/)[1],
    });
  } else if (installPackage.match(/.+@/)) {
    // Do not match @scope/ when stripping off @version or @tag
    return Promise.resolve({
      name: installPackage.charAt(0) + installPackage.substr(1).split('@')[0],
      version: installPackage.split('@')[1],
    });
  } else if (installPackage.match(/^file:/)) {
    const installPackagePath = installPackage.match(/^file:(.*)?$/)[1];
    const { name, version } = require(path.join(
      installPackagePath,
      'package.json'
    ));
    return Promise.resolve({ name, version });
  }
  return Promise.resolve({ name: installPackage });
}