/**
 * Is the value a well-formed uri?
 * Returns the untainted URI if the test value appears to be well-formed.  Note that you may really want one of the more practical methods like is_http_uri or is_https_uri, since the URI standard (RFC 3986) allows a lot of things you probably don't want.
 * @param value - The potential URI to test.
 * @returns The untainted RFC 3986 URI on success, undefined on failure.
 */
export function isUri(value: string): string | undefined;

/**
 * Is the value a well-formed HTTP uri?
 * Specialized version of isUri() that only likes http:// urls.  As a result, it can also do a much more thorough job validating.  Also, unlike isUri() it is more concerned with only allowing real-world URIs through.  Things like relative hostnames are allowed by the standards, but probably aren't wise.  Conversely, null paths aren't allowed per RFC 2616 (should be '/' instead), but are allowed by this function.
 *
 * This function only works for fully-qualified URIs.  /bob.html won't work. See RFC 3986 for the appropriate method to turn a relative URI into an absolute one given its context.
 *
 * Note that you probably want to either call this in combo with is_https_uri().
 * i.e. if(isHttpUri(uri) || isHttpsUri(uri)) console.log('Good');
 * or use the convenience method isWebUri which is equivalent.
 * @param value - The potential URI to test.
 * @returns The untainted RFC 3986 URI on success, undefined on failure.
 */
export function isHttpUri(value: string): string | undefined;

/**
 * Is the value a well-formed HTTPS uri?
 * See is_http_uri() for details.  This version only likes the https URI scheme. Otherwise it's identical to is_http_uri().
 * @param value - The potential URI to test.
 * @returns The untainted RFC 3986 URI on success, undefined on failure.
 */
export function isHttpsUri(value: string): string | undefined;

/**
 * Is the value a well-formed HTTP or HTTPS uri?
 * This is just a convenience method that combines isHttpUri and isHttpsUri to accept most common real-world URLs.
 * @param value - The potential URI to test.
 * @returns The untainted RFC 3986 URI on success, undefined on failure.
 */
export function isWebUri(value: string): string | undefined;