create-cen-app/src/utils/validateAppName.ts

create an client-engineering-style app

import { removeTrailingSlash } from "./removeTrailingSlash.js";

const validationRegExp = /^(?:@[a-z0-9-*~][a-z0-9-*._~]*\/)?[a-z0-9-~][a-z0-9-._~]*$/;

//Validate a string against allowed package.json names
export const validateAppName = (rawInput: string) => {
  const input = removeTrailingSlash(rawInput);
  const paths = input.split("/");

  // If the first part is a @, it's a scoped package
  const indexOfDelimiter = paths.findIndex((p) => p.startsWith("@"));

  let appName = paths[paths.length - 1];
  if (paths.findIndex((p) => p.startsWith("@")) !== -1) {
    appName = paths.slice(indexOfDelimiter).join("/");
  }

  if (input === "." || validationRegExp.test(appName ?? "")) {
    return;
  } else {
    return "App name must consist of only lowercase alphanumeric characters, '-', and '_'";
  }
};