import type { Plugin } from "vite";
/**
 * How the legacy interpolation transform is handled relative to the installed
 * Nix.js core and Vite plugin:
 *
 * - `"auto"` (default): the kit's legacy transform is only applied when the
 *   Vite plugin (`@deijose/vite-plugin-nix-js` >= 1.1.0) is NOT installed.
 *   The plugin has a more powerful state-machine lexer and takes precedence.
 * - `"legacy"`: always apply the kit's transform (for migrations), with a
 *   one-time deprecation warning.
 * - `"off"`: never apply the kit's transform. Recommended when the Vite
 *   plugin is installed.
 */
export type InterpolationMode = "auto" | "legacy" | "off";
/**
 * Detects whether the Vite plugin (`@deijose/vite-plugin-nix-js`) is
 * installed and provides compile-time partial attribute interpolation.
 */
export declare function pluginSupportsPartialInterpolation(): boolean;
/**
 * Detects whether the installed Nix.js core supports partial attribute
 * interpolation natively (via the public `templateFeatures` capability).
 * Note: as of core v3.4.0, this is always false — the lexer moved to the
 * Vite plugin.
 */
export declare function coreSupportsPartialInterpolation(): boolean;
/**
 * Resolves whether the kit's legacy transform should be applied.
 *
 * In `"auto"` mode, the kit's transform runs only when neither the Vite
 * plugin nor the core provides partial interpolation. When the Vite plugin
 * is installed (>= 1.1.0), it takes precedence and the kit's transform is
 * skipped to avoid double-processing.
 */
export declare function shouldUseLegacyInterpolation(mode: InterpolationMode): boolean;
/**
 * Transforms Nix.js `html\`\`` templates so that attributes with partial
 * interpolation become a single interpolation expression.
 *
 * Nix.js requires every dynamic attribute to be a single interpolation covering
 * the whole value. This plugin rewrites patterns such as:
 *
 *   html\`<a href="/blog/${slug}">...</a>\`
 *
 * into:
 *
 *   html\`<a href=${"/blog/" + slug}>...</a>\`
 *
 * Only files inside the app and islands directories are processed.
 *
 * @deprecated Nix.js core supports partial attribute interpolation natively.
 *   Keep this transform only for migrations against older cores
 *   (`interpolation: "legacy"`).
 */
export interface InterpolationPluginOptions {
    appDir?: string;
    islandsDir?: string;
}
/**
 * @deprecated Use the native partial attribute interpolation of Nix.js core
 *   (core >= 3.3). Kept for legacy migrations and direct consumers.
 */
export declare function transformPartialInterpolations(source: string): string;
export declare function nixJsInterpolationPlugin(options?: InterpolationPluginOptions): Plugin;