Add rate_limits_hit to QueryStats type

__tests__/integration/query.test.ts

@@ -37,6 +37,7 @@ const dummyResponse: HTTPResponse = {
       storage_bytes_read: 0,
       storage_bytes_write: 0,
       contention_retries: 0,
+      rate_limits_hit: ["read", "write", "compute"],
     },
   }),
   headers: {},
@@ -62,6 +63,7 @@ describe("query", () => {
     expect(result.stats?.compute_ops).toBeDefined();
     expect(result.stats?.contention_retries).toBeDefined();
     expect(result.stats?.query_time_ms).toBeDefined();
+    expect(result.stats?.rate_limits_hit).toBeDefined();
     expect(result.stats?.read_ops).toBeDefined();
     expect(result.stats?.storage_bytes_read).toBeDefined();
     expect(result.stats?.storage_bytes_write).toBeDefined();

src/errors.ts

@@ -2,6 +2,7 @@ import type {
   ConstraintFailure,
   QueryFailure,
   QueryInfo,
+  QueryStats,
   QueryValue,
 } from "./wire-protocol";
 
@@ -226,8 +227,11 @@ export class ThrottlingError extends ServiceError {
 export class QueryTimeoutError extends ServiceError {
   /**
    * Statistics regarding the query.
+   *
+   * TODO: Deprecate this `stats` field. All `ServiceError`s already provide
+   * access to stats through `queryInfo.stats`
    */
-  readonly stats?: { [key: string]: number };
+  readonly stats?: QueryStats;
 
   constructor(failure: QueryFailure, httpStatus?: number) {
     super(failure, httpStatus);

src/wire-protocol.ts

@@ -133,6 +133,11 @@ export type QueryStats = {
   contention_retries: number;
   /** The number query attempts made due to retryable errors. */
   attempts: number;
+  /**
+   * A list of rate limits hit.
+   * Included with QueryFailure responses when the query is rate limited.
+   */
+  rate_limits_hit?: ("read" | "write" | "compute")[];
 };
 
 export type QueryInfo = {