import type { Node } from '@babel/types';
/**
 * Parse a replacement source fragment into a single expression AST node,
 * wrapping in parens exactly as `instrument-worker.mjs` `parseFragment` does so
 * object/sequence-shaped fragments parse as expressions. Returns the parsed
 * {@link Node} on success, or `undefined` when the fragment is not a valid
 * expression (e.g. a statement-shaped replacement, or syntactically invalid
 * text) — the caller decides whether to drop-and-log.
 *
 * Pure and offline: `@babel/parser` does no I/O and no network. A FRESH node is
 * produced on every call (the parser allocates a new tree), which is exactly the
 * distinct-node-identity-per-yield property the `LLMMutator` relies on (yielding
 * the same node object for two candidates collapses them in Stryker's placement
 * map).
 */
export declare function parseReplacementFragment(code: string): Node | undefined;