import { ErrorChain } from "../lib/error";
/** Environment variables object. */
export interface IEnvironmentVariables {
    [key: string]: string | undefined;
}
/** Environment error codes. */
export declare enum EEnvironmentError {
    Get = "EnvironmentError.Get"
}
/** Environment error class. */
export declare class EnvironmentError extends ErrorChain {
    constructor(code: EEnvironmentError, cause?: Error, context?: object);
}
/** Environment variables class. */
export declare class Environment {
    readonly variables: IEnvironmentVariables;
    constructor(...variables: IEnvironmentVariables[]);
    /** Returns a copy of environment. */
    copy(...variables: IEnvironmentVariables[]): Environment;
    /** Returns true if environment variable key is set. */
    has(key: string): boolean;
    /**
     * Get an environment variable value, or default value.
     * Throws EnvironmentError if value is undefined and no default value provided.
     */
    get(key: string, orDefault?: string): string;
    /** Set an environment variable value. */
    set(key: string, value: string): Environment;
}