feat: add warning for individual pagination with union search

src/Typesense/ApiCall.ts

@@ -103,7 +103,7 @@ export default class ApiCall implements HttpClient {
   private readonly numRetriesPerRequest: number;
   private readonly additionalUserHeaders?: Record<string, string>;
 
-  private readonly logger: Logger;
+  readonly logger: Logger;
   private currentNodeIndex: number;
 
   constructor(private configuration: Configuration) {

src/Typesense/MultiSearch.ts

@@ -18,18 +18,21 @@ import type {
   UnionSearchResponse,
   MultiSearchRequestsWithoutUnionSchema,
 } from "./Types";
+import { Logger } from "loglevel";
 
 const RESOURCEPATH = "/multi_search";
 
 export default class MultiSearch {
   private requestWithCache: RequestWithCache;
+  readonly logger: Logger;
 
   constructor(
     private apiCall: ApiCall,
     private configuration: Configuration,
     private useTextContentType: boolean = false,
   ) {
     this.requestWithCache = new RequestWithCache();
+    this.logger = this.apiCall.logger;
   }
 
   clearCache() {
@@ -74,6 +77,12 @@ export default class MultiSearch {
       params.use_cache = true;
     }
 
+    if (searchRequests.union === true && this.hasAnySearchObjectPagination(searchRequests)) {
+      this.logger.warn(
+        "Individual `searches` pagination parameters are ignored when `union: true` is set. Use a top-level pagination parameter instead. See https://typesense.org/docs/29.0/api/federated-multi-search.html#union-search"
+      );
+    }
+
     const normalizedSearchRequests: Omit<typeof searchRequests, "searches"> & {
       searches: ExtractBaseTypes<SearchParams<T[number], Infix>>[];
     } = {
@@ -115,6 +124,10 @@ export default class MultiSearch {
   private isStreamingRequest(commonParams: { streamConfig?: unknown }) {
     return commonParams.streamConfig !== undefined;
   }
+
+  private hasAnySearchObjectPagination(searchRequests: MultiSearchRequestsSchema<DocumentSchema, string>) {
+    return searchRequests.searches.some(search => search.page !== undefined || search.per_page !== undefined || search.offset !== undefined || search.limit !== undefined || search.limit_hits !== undefined);
+  }
 }
 
 export type {

test/Typesense/MultiSearch.spec.ts

@@ -1,6 +1,7 @@
-import { describe, it, expect, beforeEach, afterEach } from "vitest";
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
 import { Client as TypesenseClient } from "../../src/Typesense";
 import { ObjectNotFound } from "../../src/Typesense/Errors";
+import logger from "loglevel";
 
 type MultiSearchResult = {
   title: string;
@@ -9,6 +10,14 @@ type MultiSearchResult = {
 };
 
 describe("MultiSearch", function () {
+  const mockConsole = {
+    error: vi.fn(),
+    warn: vi.fn(),
+    info: vi.fn(),
+    log: vi.fn(),
+    debug: vi.fn(),
+  };
+
   const typesense = new TypesenseClient({
     nodes: [
       {
@@ -45,6 +54,18 @@ describe("MultiSearch", function () {
   ];
 
   beforeEach(async function () {
+    // Setup console mocking
+    vi.spyOn(console, "error").mockImplementation(mockConsole.error);
+    vi.spyOn(console, "warn").mockImplementation(mockConsole.warn);
+    vi.spyOn(console, "info").mockImplementation(mockConsole.info);
+    vi.spyOn(console, "log").mockImplementation(mockConsole.log);
+    vi.spyOn(console, "debug").mockImplementation(mockConsole.debug);
+
+    typesense.multiSearch.logger.setLevel(logger.levels.INFO);
+
+    // Clear any previous mock calls
+    vi.clearAllMocks();
+
     try {
       await typesense.collections(testCollectionName).delete();
     } catch (error) {
@@ -218,5 +239,59 @@ describe("MultiSearch", function () {
       expect(result.results[0].hits?.length).toBe(0);
       expect(result.results[1].hits?.length).toBe(0);
     });
+
+    it("warns when individual search pagination is used with union: true", async function () {
+      const searches = {
+        union: true as const,
+        searches: [
+          { q: "first", query_by: "title", page: 1 },
+          { q: "second", query_by: "title", per_page: 10 },
+        ],
+      };
+      const commonParams = {
+        collection: testCollectionName,
+      };
+
+      await typesense.multiSearch.perform(searches, commonParams);
+
+      expect(mockConsole.warn).toHaveBeenCalledWith(
+        "Individual `searches` pagination parameters are ignored when `union: true` is set. Use a top-level pagination parameter instead. See https://typesense.org/docs/29.0/api/federated-multi-search.html#union-search"
+      );
+    });
+
+    it("does not warn when union: true is used without individual search pagination", async function () {
+      const searches = {
+        union: true as const,
+        searches: [
+          { q: "first", query_by: "title" },
+          { q: "second", query_by: "title" },
+        ],
+      };
+      const commonParams = {
+        collection: testCollectionName,
+        page: 1, // top-level pagination is fine
+      };
+
+      await typesense.multiSearch.perform(searches, commonParams);
+
+      expect(mockConsole.warn).not.toHaveBeenCalled();
+    });
+
+    it("does not warn when union is false with individual search pagination", async function () {
+      const searches = {
+        union: false as const,
+        searches: [
+          { q: "first", query_by: "title", page: 1 },
+          { q: "second", query_by: "title", per_page: 10 },
+        ],
+      };
+      const commonParams = {
+        collection: testCollectionName,
+      };
+
+      await typesense.multiSearch.perform(searches, commonParams);
+
+      expect(mockConsole.warn).not.toHaveBeenCalled();
+    });
   });
 });