export interface Transform {
  regexp: RegExp;
  transformer(...arg: string[]): any;
  useForSnippets?: boolean;
  preferForRegexpMatch?: boolean;
  name?: string;
  typeName?: string; // deprecated
}

export function defineStep(
  expression: RegExp | string,
  implementation: (...args: any[]) => void
): void;
export function defineParameterType(parameterType: Transform): void;

// Aliased versions of the above funcs.
export function Given(
  expression: RegExp | string,
  implementation: (...args: any[]) => void
): void;
export function Given(
  expression: RegExp | string,
  config: { timeout?: number },
  implementation: (...args: any[]) => void
): void;
export function When(
  expression: RegExp | string,
  implementation: (...args: any[]) => void
): void;
export function When(
  expression: RegExp | string,
  config: { timeout?: number },
  implementation: (...args: any[]) => void
): void;
export function Then(
  expression: RegExp | string,
  implementation: (...args: any[]) => void
): void;
export function Then(
  expression: RegExp | string,
  config: { timeout?: number },
  implementation: (...args: any[]) => void
): void;
export function And(
  expression: RegExp | string,
  implementation: (...args: any[]) => void
): void;
export function And(
  expression: RegExp | string,
  config: { timeout?: number },
  implementation: (...args: any[]) => void
): void;
export function But(
  expression: RegExp | string,
  implementation: (...args: any[]) => void
): void;
export function But(
  expression: RegExp | string,
  config: { timeout?: number },
  implementation: (...args: any[]) => void
): void;
export function Before(
  optionsOrImplementation: object | ((...args: any[]) => void),
  implementation?: (...args: any[]) => void
): void;
export function After(
  optionsOrImplementation: object | ((...args: any[]) => void),
  implementation?: (...args: any[]) => void
): void;