import { type GraphQLSchema } from 'graphql';
import type { SchemaBuildErrorInfo } from './schema-manager';
import type { SchemaManagerHost } from './types';
export declare class ExtensionManager {
    private _host;
    private _targetSdlFileNames;
    private _parsedExtensionAstMap;
    private _graphqlErrorMap;
    constructor(_host: SchemaManagerHost);
    readExtensions(): void;
    extendSchema(baseSchema: GraphQLSchema): GraphQLSchema | null;
    getSchemaErrors(): SchemaBuildErrorInfo[];
    startWatch(cb: () => void, interval?: number): void;
    private _readExtension;
    private _getAbsoluteSchemaPath;
}