function checkAppName()

in packages/create-react-app/createReactApp.js [821:856]

• 34 lines of code
• 5 McCabe index (conditional complexity)

function checkAppName(appName) {
  const validationResult = validateProjectName(appName);
  if (!validationResult.validForNewPackages) {
    console.error(
      chalk.red(
        `Cannot create a project named ${chalk.green(
          `"${appName}"`
        )} because of npm naming restrictions:\n`
      )
    );
    [
      ...(validationResult.errors || []),
      ...(validationResult.warnings || []),
    ].forEach(error => {
      console.error(chalk.red(`  * ${error}`));
    });
    console.error(chalk.red('\nPlease choose a different project name.'));
    process.exit(1);
  }

  // TODO: there should be a single place that holds the dependencies
  const dependencies = ['react', 'react-dom', 'react-scripts'].sort();
  if (dependencies.includes(appName)) {
    console.error(
      chalk.red(
        `Cannot create a project named ${chalk.green(
          `"${appName}"`
        )} because a dependency with the same name exists.\n` +
          `Due to the way npm works, the following names are not allowed:\n\n`
      ) +
        chalk.cyan(dependencies.map(depName => `  ${depName}`).join('\n')) +
        chalk.red('\n\nPlease choose a different project name.')
    );
    process.exit(1);
  }
}