import type { CodeMapping } from "@volar/language-core";
import type { FrontmatterSchemaEntry } from "./options.js";
/** The generated code for the frontmatter validation and its source mappings. */
export interface FrontmatterValidation {
    /** JS appended to the embedded file. */
    text: string;
    /** Mappings whose parallel arrays relocate generated tokens onto the MDX source. */
    mappings: CodeMapping[];
}
/** Extract the leading YAML frontmatter block and its offset within the MDX. */
export declare function extractYamlFrontmatter(mdx: string): {
    yaml: string;
    offset: number;
} | undefined;
/**
 * Build code that type-checks parsed frontmatter against the schema, arranged so
 * TypeScript names the offending field:
 *
 * - An inferred value object assigned to a `T`-typed const surfaces missing
 *   fields (TS2741 "Property 'x' is missing") and wrong-typed values (TS2322
 *   "Types of property 'x' are incompatible") — both naming the field. These
 *   map to the frontmatter block.
 * - A separate keys-only literal, typed to reject unknown keys, surfaces excess
 *   keys (TS2353 naming the key), mapped to the exact key in the YAML.
 *
 * Returns undefined when there is nothing checkable (empty or non-object YAML,
 * or YAML that itself fails to parse).
 */
export declare function buildFrontmatterValidation(yaml: string, blockOffset: number, entry: FrontmatterSchemaEntry): FrontmatterValidation | undefined;