/**
 * @license
 * Copyright 2023 Google LLC
 * SPDX-License-Identifier: BSD-3-Clause
 */
import ts from 'typescript';
/**
 * Fail type checking if the first argument is not `never` and return the
 * argument.
 */
export declare function unreachable(x: never): never;
/**
 * A [TypeScript
 * Transformer](https://github.com/itsdouges/typescript-transformer-handbook#the-basics)
 * that optimizes lit templates.
 *
 * This transform should be used in your build setup, and will need to be used
 * with a tool that consumes TypeScript transformers. An example usage with
 * Rollup.js and @rollup/plugin-typescript is:
 *
 * @example
 * ```
 * // File: rollup.config.js
 * import typescript from '@rollup/plugin-typescript';
 * import {compileLitTemplates} from '@lit-labs/compiler';
 *
 * export default {
 *   // ...
 *   plugins: [
 *     typescript({
 *       transformers: {
 *         before: [compileLitTemplates()],
 *       },
 *     }),
 *     // other rollup plugins
 *   ],
 * };
 * ```
 */
export declare const compileLitTemplates: () => ts.TransformerFactory<ts.SourceFile>;
//# sourceMappingURL=template-transform.d.ts.map