export type Options = {
	/**
	String to use as replacement for reserved filename characters.

	Cannot contain: `<` `>` `:` `"` `/` `\` `|` `?` `*` or control characters.

	@default '!'
	*/
	readonly replacement?: string;

	/**
	Truncate the filename to the given length.

	Only the base of the filename is truncated, preserving the extension. If the extension itself is longer than `maxLength`, you will get a string that is longer than `maxLength`, so you need to check for that if you allow arbitrary extensions.

	Truncation is grapheme-aware and will not split Unicode characters (surrogate pairs or extended grapheme clusters). If the remaining budget (after accounting for the extension) is smaller than a whole grapheme, the base filename may be truncated to an empty string to avoid splitting.

	Systems generally allow up to 255 characters, but we default to 100 for usability reasons.

	@default 100
	*/
	readonly maxLength?: number;
};

/**
Convert a string to a valid filename.

@example
```
import filenamify from 'filenamify';

filenamify('<foo/bar>');
//=> '!foo!bar!'

filenamify('foo:"bar"', {replacement: '🐴'});
//=> 'foo🐴bar🐴'
```
*/
export default function filenamify(string: string, options?: Options): string;