import type { MigrationDiff, MigrationRiskSummary } from './migration-types.js';
/**
 * Create a risk summary with every bucket initialized to zero items.
 *
 * The five buckets are: `additive` (additions, hydrations, default-value
 * changes), `removal` (attribute drops), `rename` (detected renames),
 * `semanticTransform` (coercion suggestions), and `unionBreaking`
 * (discriminated-union branch removals or discriminator changes).
 *
 * @returns A risk summary whose buckets all carry empty item lists.
 */
export declare function createEmptyMigrationRiskSummary(): MigrationRiskSummary;
/**
 * Format a risk summary into a single-line human-readable string.
 *
 * @param summary Risk summary to format.
 * @returns A comma-separated string with per-bucket counts, including
 *   `removal` (attribute drops) distinguished from `additive`.
 */
export declare function formatMigrationRiskSummary(summary: MigrationRiskSummary): string;
/**
 * Classify a migration diff into five risk buckets.
 *
 * `additive` collects low-risk auto outcomes (add-default, add-optional,
 * default-change, hydrate, union-branch-addition). `removal` collects
 * attribute drops (`drop` kind) separately so data-loss edges are not hidden
 * inside additive. `rename`, `semanticTransform`, and `unionBreaking` capture
 * their respective diff categories.
 *
 * @param diff Migration diff whose summary items are classified.
 * @returns A risk summary with deduplicated items per bucket.
 */
export declare function createMigrationRiskSummary(diff: MigrationDiff): MigrationRiskSummary;