import { SemanticVersion } from './isSemanticVersion.js';
/**
 * A version of the CKEditor that is used for testing purposes.
 */
export type CKTestingVersion = 'nightly' | `nightly-${string}` | 'alpha' | 'staging' | 'internal';
/**
 * A version of the CKEditor.
 */
export type CKVersion = SemanticVersion | CKTestingVersion;
/**
 * Checks if the given string is a version of a file on the CKEditor.
 *
 * @param version - The string to check.
 * @returns `true` if the string is a version of a file on the CKEditor, `false` otherwise.
 * @example
 * ```ts
 * isCKTestingVersion( '1.2.3-nightly-abc' ); // -> true
 * isCKTestingVersion( '1.2.3-internal-abc' ); // -> true
 * isCKTestingVersion( '1.2.3-alpha.1' ); // -> true
 * isCKTestingVersion( '1.2.3' ); // -> false
 * isCKTestingVersion( 'nightly' ); // -> true
 * isCKTestingVersion( 'nightly-abc' ); // -> true
 * isCKTestingVersion( 'staging' ); // -> true
 * ```
 */
export declare function isCKTestingVersion(version: string | undefined): version is CKTestingVersion;
/**
 * Checks if given version is nightly like version with `0.0.0` versioning.
 *
 * @param version - The version to check.
 * @returns `true` if it's nightly-like version.
 */
export declare function isCKZeroBaseVersion(version: string | undefined): version is SemanticVersion;
/**
 * Checks if the given string is a version of a file on the CKEditor CDN.
 *
 * @param version - The string to check.
 * @returns `true` if the string is a version of a file on the CKEditor, `false` otherwise.
 * @example
 * ```ts
 * isCKVersion( 'nightly' ); // -> true
 * isCKVersion( 'alpha' ); // -> true
 * isCKVersion( 'rc-1.2.3' ); // -> true
 * isCKVersion( '1.2.3' ); // -> true
 * isCKVersion( 'nightly-abc' ); // -> true
 * isCKVersion( 'staging' ); // -> true
 * ```
 */
export declare function isCKVersion(version: string | undefined): version is CKVersion;