/**
 * Detect whether an error (or AggregateError wrapping multiple attempts)
 * represents an ECONNREFUSED — i.e. the database is simply not running.
 *
 * Handles:
 * - Direct `{ code: "ECONNREFUSED" }` errors from Node `net`
 * - `AggregateError` from dual-stack IPv4+IPv6 connection attempts
 * - Drizzle's `cause`-wrapped pg errors
 */
export declare function isEconnrefused(err: unknown): boolean;
/**
 * Detect PostgreSQL authentication failures.
 * PG error codes: 28P01 (invalid_password), 28000 (invalid_authorization_specification)
 */
export declare function isAuthFailure(err: unknown): boolean;
/**
 * Detect the "SSL is not enabled on the server" failure — the client attempted
 * an SSL handshake against a Postgres server that doesn't support it (common
 * with a plain local dev database). The fix is `?sslmode=disable` on the URL.
 */
export declare function isSslNotEnabled(err: unknown): boolean;
/**
 * Detect PostgreSQL "cannot drop ... because other objects depend on it"
 * (error code 2BP01, dependent_objects_still_exist). This is the failure that
 * strands a declarative `db push` half-applied when a collection is removed but
 * an enum type it defined is still referenced by another object.
 */
export declare function isDependencyDropError(err: unknown): boolean;
/**
 * Pre-flight check: verify that the database is reachable before running
 * a heavy subprocess (Atlas, migrations, etc.).
 *
 * Exits with code 1 and a friendly banner on known failure modes.
 * On unknown errors, logs a warning and allows the caller to proceed.
 */
export declare function checkDatabaseConnectivity(databaseUrl: string): Promise<void>;
/**
 * Post-hoc error diagnosis for direct database operations (e.g. applyPolicies).
 * Returns a formatted diagnostic string if the error matches a known pattern,
 * or null if unrecognized.
 */
export declare function diagnoseDbError(err: unknown, databaseUrl?: string): string | null;