function getShortName()

in packages/metro-transform-plugins/src/normalizePseudoGlobals.js [69:96]

• 21 lines of code
• 8 McCabe index (conditional complexity)

function getShortName(fullName: string, usedNames: Set<string>): string {
  // Try finding letters that are semantically relatable to the name
  // of the variable given. For instance, in XMLHttpRequest, it will
  // first match "X", then "H", then "R".
  const regexp = /^[^A-Za-z]*([A-Za-z])|([A-Z])[a-z]|([A-Z])[A-Z]+$/g;
  let match;

  while ((match = regexp.exec(fullName))) {
    const name = (match[1] || match[2] || match[3] || '').toLowerCase();

    if (!name) {
      throw new ReferenceError(
        'Could not identify any valid name for ' + fullName,
      );
    }

    if (!usedNames.has(name)) {
      usedNames.add(name);
      return name;
    }
  }

  throw new ReferenceError(
    `Unable to determine short name for ${fullName}. The variables are not unique: ${Array.from(
      usedNames,
    ).join(', ')}`,
  );
}