/** Portable type compatible with `process.env`. */
export interface ProcessEnv {
    readonly [key: string]: string | undefined;
}
/**
 * Runs a function in a patched environment. The original environment is
 * restored after the function returns.
 */
export declare function patchingEnv<V>(patch: ProcessEnv, fn: () => Promise<V>): Promise<V>;
export declare function patchingEnv<V>(patch: ProcessEnv, base: ProcessEnv, fn: () => Promise<V>): Promise<V>;
/** Environment checks interface. */
export interface Running {
    inProduction(): boolean;
    inTest(): boolean;
}
/** Default environment check implementation. */
export declare const running: Running;