import Maybe from "../../tsutils/Maybe";
import { ValidationContext } from "../ValidationContext";
import { ASTVisitor } from "../../language/visitor";

export function unusedVariableMessage(varName: string, opName: Maybe<string>): string;

/**
 * No unused variables
 *
 * A GraphQL operation is only valid if all variables defined by an operation
 * are used, either directly or within a spread fragment.
 */
export function NoUnusedVariables(context: ValidationContext): ASTVisitor;