import { DefaultRuleOptions } from 'stylelint-rule-creator';
export declare type FileExtensionRuleOptions = DefaultRuleOptions & {
    /**
     * This is only use if the rule is required and an import is missing the extension. If "block"
     * mode is used, then all extensions are removed, not just the one provided here.
     */
    extension: string;
};
export declare const fileExtensionRule: import("stylelint-rule-creator").DefaultRule<FileExtensionRuleOptions, {
    extensionRequired(line: string, extension: string): string;
    extensionBlocked(line: string): string;
} & {
    invalidOptions(option: any): string;
}>;