feat: non-streaming search api with pagination (#92)

src/__tests__/cursor/cursor.spec.ts

@@ -0,0 +1,96 @@
+import {Server, ServerCredentials} from "@grpc/grpc-js";
+import TestService, {TestTigrisService} from "../test-service";
+import {TigrisService} from "../../proto/server/v1/api_grpc_pb";
+import {IBook} from "../tigris.rpc.spec";
+import {Tigris} from "../../tigris";
+import {TigrisCursorInUseError} from "../../error";
+import {ObservabilityService} from "../../proto/server/v1/observability_grpc_pb";
+import TestObservabilityService from "../test-observability-service";
+import {ReadResponse} from "../../proto/server/v1/api_pb";
+import {DB} from "../../db";
+
+describe("class FindCursor", () => {
+	let server: Server;
+	const SERVER_PORT = 5003;
+	let db: DB;
+
+	beforeAll((done) => {
+		server = new Server();
+		TestTigrisService.reset();
+		server.addService(TigrisService, TestService.handler.impl);
+		server.addService(ObservabilityService, TestObservabilityService.handler.impl);
+		server.bindAsync(
+			"0.0.0.0:" + SERVER_PORT,
+			// test purpose only
+			ServerCredentials.createInsecure(),
+			(err: Error | null) => {
+				if (err) {
+					console.log(err);
+				} else {
+					server.start();
+				}
+			}
+		);
+		const tigris = new Tigris({serverUrl: "0.0.0.0:" + SERVER_PORT, insecureChannel: true});
+		db = tigris.getDatabase("db3");
+		done();
+	});
+
+	beforeEach(() => {
+		TestTigrisService.reset();
+	});
+
+	afterAll((done) => {
+		server.forceShutdown();
+		done();
+	});
+
+	it("returns iterable stream as it is", async () => {
+		const cursor = db.getCollection<IBook>("books").findMany();
+		let bookCounter = 0;
+		for await (const book of cursor) {
+			expect(book.id).toBeDefined();
+			bookCounter++;
+		}
+		expect(bookCounter).toBeGreaterThan(0);
+	})
+
+	it("Pipes the stream as iterable", async () => {
+		const cursor = db.getCollection<IBook>("books").findMany();
+		let bookCounter = 0;
+		for await (const book of cursor.stream()) {
+			expect(book.id).toBeDefined();
+			bookCounter++;
+		}
+		expect(bookCounter).toBeGreaterThan(0);
+	})
+
+	it("returns stream as an array", () => {
+		const cursor = db.getCollection<IBook>("books").findMany();
+		const booksPromise = cursor.toArray();
+		booksPromise.then(books => expect(books.length).toBeGreaterThan(0));
+
+		return booksPromise;
+	})
+
+	it("does not allow cursor to be re-used", () => {
+		const cursor = db.getCollection<IBook>("books").findMany();
+		// cursor.stream() is a generator fn, calling next() would retrieve item from stream
+		cursor.stream().next();
+		expect(() => cursor.toArray()).toThrow(TigrisCursorInUseError);
+	})
+
+	it("allows cursor to be re-used once reset", async () => {
+		const cursor = db.getCollection<IBook>("books").findMany();
+
+		let bookCounter = 0;
+		for await (const book of cursor.stream()) {
+			expect(book.id).toBeDefined();
+			bookCounter++;
+		}
+
+		cursor.reset()
+		const books = await cursor.toArray();
+		expect(books.length).toBe(bookCounter);
+	})
+});

src/__tests__/test-service.ts

@@ -196,7 +196,8 @@ export class TestTigrisService {
 			_call: ServerUnaryCall<DescribeCollectionRequest, DescribeCollectionResponse>,
 			// eslint-disable-next-line @typescript-eslint/no-unused-vars
 			_callback: sendUnaryData<DescribeCollectionResponse>
-		): void {},
+		): void {
+		},
 		/* eslint-enable @typescript-eslint/no-empty-function */
 
 		describeDatabase(
@@ -376,37 +377,47 @@ export class TestTigrisService {
 		},
 		// eslint-disable-next-line @typescript-eslint/no-empty-function
 		search(call: ServerWritableStream<SearchRequest, SearchResponse>): void {
-			// empty search response to stream
-			call.write(new SearchResponse());
-
-			// with only meta and not page
 			const searchMeta = new SearchMetadata().setFound(5).setTotalPages(5);
-			call.write(new SearchResponse().setMeta(searchMeta));
 
-			// with meta and page
-			const searchPage = new Page().setSize(1).setCurrent(1);
+			// paginated search impl
+			if (call.request.getPage() > 0) {
+				const searchPage = new Page()
+					.setSize(call.request.getPageSize())
+					.setCurrent(call.request.getPage());
+				const resp = new SearchResponse().setMeta(searchMeta.setPage(searchPage));
+				call.write(resp);
+				call.end();
+			} else {
+				// empty search response to stream
+				call.write(new SearchResponse());
 
-			call.write(new SearchResponse().setMeta(searchMeta.setPage(searchPage)));
+				// with only meta and not page
+				call.write(new SearchResponse().setMeta(searchMeta));
 
-			// with facets, meta and page
-			const searchFacet = new SearchFacet().setCountsList(
-				[new FacetCount().setCount(2).setValue("Marcel Proust")]);
-			const resp = new SearchResponse().setMeta(searchMeta.setPage(searchPage));
-			resp.getFacetsMap().set("author", searchFacet);
-			call.write(resp);
+				// with meta and page
+				const searchPage = new Page().setSize(1).setCurrent(1);
+				call.write(new SearchResponse().setMeta(searchMeta.setPage(searchPage)));
 
-			// with first hit, meta and page
-			const searchHitMeta = new SearchHitMeta().setUpdatedAt(new google_protobuf_timestamp_pb.Timestamp());
-			const searchHit = new SearchHit().setMetadata(searchHitMeta);
+				// with facets, meta and page
+				const searchFacet = new SearchFacet().setCountsList(
+					[new FacetCount().setCount(2).setValue("Marcel Proust")]);
+				const resp = new SearchResponse().setMeta(searchMeta.setPage(searchPage));
+				resp.getFacetsMap().set("author", searchFacet);
+				call.write(resp);
 
-			// write all search hits to stream 1 by 1
-			// eslint-disable-next-line @typescript-eslint/no-unused-vars,@typescript-eslint/ban-ts-comment
-			// @ts-ignore
-			for (const booksb64BYIDElement of TestTigrisService.BOOKS_B64_BY_ID) {
-				searchHit.setData(booksb64BYIDElement[1]);
-				call.write(resp.setHitsList([searchHit]));
+				// with first hit, meta and page
+				const searchHitMeta = new SearchHitMeta().setUpdatedAt(new google_protobuf_timestamp_pb.Timestamp());
+				const searchHit = new SearchHit().setMetadata(searchHitMeta);
+
+				// write all search hits to stream 1 by 1
+				// eslint-disable-next-line @typescript-eslint/no-unused-vars,@typescript-eslint/ban-ts-comment
+				// @ts-ignore
+				for (const booksb64BYIDElement of TestTigrisService.BOOKS_B64_BY_ID) {
+					searchHit.setData(booksb64BYIDElement[1]);
+					call.write(resp.setHitsList([searchHit]));
+				}
+				call.end();
 			}
-			call.end();
 		},
 		/* eslint-disable @typescript-eslint/no-empty-function */
 		replace(