Function getDisplayName

packages/react-devtools-shared/src/utils.js:146–168

(
  type: Function,
  fallbackName: string = 'Anonymous',
)

}

export function getDisplayName(
  type: Function,
  fallbackName: string = 'Anonymous',
): string {
  const nameFromCache = cachedDisplayNames.get(type);
  if (nameFromCache != null) {
    return nameFromCache;
  }

  let displayName = fallbackName;

  // The displayName property is not guaranteed to be a string.
  // It's only safe to use for our purposes if it's a string.
  // github.com/facebook/react-devtools/issues/803
  if (typeof type.displayName === 'string') {
    displayName = type.displayName;
  } else if (typeof type.name === 'string' && type.name !== '') {
    displayName = type.name;
  }

  cachedDisplayNames.set(type, displayName);
  return displayName;
}

let uidCounter: number = 0;