import { HttpBackend } from './backend';
import { HttpFetchBackend } from './fetch';
import { HttpInterceptor, HttpInterceptorFn } from './interceptor';
import { HttpXhrBackend } from './xhr';
export declare enum HttpFeatureKind {
    Backend = 0,
    Interceptors = 1,
    LegacyInterceptors = 2,
    XsrfProtection = 3
}
export type HttpFeature = {
    kind: HttpFeatureKind.Backend;
    value: HttpBackend;
} | {
    kind: HttpFeatureKind.Interceptors;
    value: HttpInterceptorFn[];
} | {
    kind: HttpFeatureKind.LegacyInterceptors;
    value: HttpInterceptor[];
} | {
    kind: HttpFeatureKind.XsrfProtection;
    value: HttpInterceptorFn;
};
export declare function withXhr(factory?: () => XMLHttpRequest): {
    readonly kind: HttpFeatureKind.Backend;
    readonly value: HttpXhrBackend;
};
export declare function withFetch(fetchImpl?: typeof fetch): {
    readonly kind: HttpFeatureKind.Backend;
    readonly value: HttpFetchBackend;
};
export declare function withInterceptors(interceptorFns: HttpInterceptorFn[]): {
    readonly kind: HttpFeatureKind.Interceptors;
    readonly value: HttpInterceptorFn[];
};
export declare function withLegacyInterceptors(interceptors: HttpInterceptor[]): {
    readonly kind: HttpFeatureKind.LegacyInterceptors;
    readonly value: HttpInterceptor[];
};
export declare function withXsrfProtection(options?: {
    cookieName?: string;
    headerName?: string;
    tokenExtractor?: () => string | null;
}): {
    readonly kind: HttpFeatureKind.XsrfProtection;
    readonly value: HttpInterceptorFn;
};