/**
 * @license
 * Copyright Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */
import '../environment/dev.js';
/**
 * Extracts the scheme from the given URL. If the URL is relative, https: is
 * assumed.
 * @param url The URL to extract the scheme from.
 * @return the URL scheme.
 */
export declare function extractScheme(url: string): string | undefined;
/**
 * A pattern that blocks javascript: URLs. Matches
 * (a) Urls with an explicit scheme that is not javascript and that only has
 *     alphanumeric or [.-+_] characters; or
 * (b) Urls with no explicit scheme. The pattern allows the first colon
 *     (`:`) character to appear after one of  the `/` `?` or `#` characters,
 *     which means the colon appears in path, query or fragment part of the URL.
 */
export declare const IS_NOT_JAVASCRIPT_URL_PATTERN: RegExp;
/**
 * Checks whether a urls has a `javascript:` scheme.
 * If the url has a `javascript:` scheme, reports it and returns true.
 * Otherwise, returns false.
 */
export declare function reportJavaScriptUrl(url: string): boolean;
/**
 * Checks that the URL scheme is not javascript.
 * The URL parsing relies on the URL API in browsers that support it.
 * @param url The URL to sanitize for a SafeUrl sink.
 * @return undefined if url has a javascript: scheme, the original URL
 *     otherwise.
 */
export declare function sanitizeJavaScriptUrl(url: string): string | undefined;
/**
 * Type alias for URLs passed to DOM sink wrappers.
 */
export declare type Url = string;
/**
 * Adapter to sanitize string URLs in DOM sink wrappers.
 * @return undefined if the URL was sanitized.
 */
export declare function unwrapUrlOrSanitize(url: Url): string | undefined;
/**
 * Sanitizes a URL restrictively.
 * This sanitizer protects against XSS and potentially other uncommon and
 * undesirable schemes that an attacker could use e.g. phishing (tel:, callto:
 * ssh: etc schemes). This sanitizer is primarily meant to be used by the HTML
 * sanitizer.
 */
export declare function restrictivelySanitizeUrl(url: string): string;