Enable esm testing in odsp-driver

packages/drivers/odsp-driver/package.json

@@ -59,8 +59,7 @@
 		"build:docs": "api-extractor run --local",
 		"build:esnext": "tsc --project ./tsconfig.json",
 		"build:genver": "gen-version",
-		"build:test": "npm run build:test:esm && npm run build:test:cjs",
-		"build:test:cjs": "fluid-tsc commonjs --project ./src/test/tsconfig.cjs.json",
+		"build:test": "npm run build:test:esm",
 		"build:test:esm": "tsc --project ./src/test/tsconfig.json",
 		"check:are-the-types-wrong": "attw --pack .",
 		"check:biome": "biome check .",
@@ -86,7 +85,7 @@
 		"lint:fix": "fluid-build . --task eslint:fix --task format",
 		"test": "npm run test:mocha",
 		"test:coverage": "c8 npm test",
-		"test:mocha": "npm run test:mocha:cjs && echo \"ADO #7404 - ESM modules cannot be stubbed - npm run test:mocha:esm\"",
+		"test:mocha": "npm run test:mocha:esm",
 		"test:mocha:cjs": "mocha --recursive \"dist/test/**/*.spec.*js\" --exit",
 		"test:mocha:esm": "mocha --recursive \"lib/test/**/*.spec.*js\" --exit",
 		"test:mocha:verbose": "cross-env FLUID_TEST_VERBOSE=1 npm run test:mocha",

packages/drivers/odsp-driver/src/fetchSnapshot.ts

@@ -46,6 +46,7 @@ import {
 import { EpochTracker } from "./epochTracker.js";
 import { getQueryString } from "./getQueryString.js";
 import { getHeadersWithAuth } from "./getUrlAndHeadersWithAuth.js";
+import { mockify } from "./mockify.js";
 import { convertOdspSnapshotToSnapshotTreeAndBlobs } from "./odspSnapshotParser.js";
 import { checkForKnownServerFarmType } from "./odspUrlHelper.js";
 import {
@@ -693,7 +694,7 @@ function getTreeStatsCore(snapshotTree: ISnapshotTree, stats: ITreeStats): void
  * @param epochTracker - epoch tracker used to add/validate epoch in the network call.
  * @returns fetched snapshot.
  */
-export async function downloadSnapshot(
+async function downloadSnapshot(
 	odspResolvedUrl: IOdspResolvedUrl,
 	getAuthHeader: InstrumentedStorageTokenFetcher,
 	tokenFetchOptions: TokenFetchOptionsEx,
@@ -775,6 +776,9 @@ export async function downloadSnapshot(
 	};
 }
 
+const mockableDownloadSnapshot = mockify(downloadSnapshot);
+export { mockableDownloadSnapshot as downloadSnapshot };
+
 function isRedeemSharingLinkError(
 	odspResolvedUrl: IOdspResolvedUrl,
 	error: Partial<IOdspError>,

packages/drivers/odsp-driver/src/getFileLink.ts

@@ -20,6 +20,7 @@ import {
 } from "@fluidframework/telemetry-utils/internal";
 
 import { getHeadersWithAuth } from "./getUrlAndHeadersWithAuth.js";
+import { mockify } from "./mockify.js";
 import {
 	fetchHelper,
 	getWithRetryForTokenRefresh,
@@ -42,7 +43,7 @@ const fileLinkCache = new Map<string, Promise<string>>();
  * @param logger - used to log results of operation, including any error
  * @returns Promise which resolves to file link url when successful; otherwise, undefined.
  */
-export async function getFileLink(
+async function getFileLink(
 	getToken: TokenFetcher<OdspResourceTokenFetchOptions>,
 	resolvedUrl: IOdspResolvedUrl,
 	logger: ITelemetryLoggerExt,
@@ -101,6 +102,9 @@ export async function getFileLink(
 	return fileLink;
 }
 
+const mockableGetFileLink = mockify(getFileLink);
+export { mockableGetFileLink as getFileLink };
+
 /**
  * Handles location redirection while fulfilling the getFileLink call. We don't want browser to handle
  * the redirection as the browser will retry with same auth token which will not work as we need app

packages/drivers/odsp-driver/src/mockify.ts

@@ -0,0 +1,67 @@
+/*!
+ * Copyright (c) Microsoft Corporation and contributors. All rights reserved.
+ * Licensed under the MIT License.
+ */
+
+/**
+ * A special key used to store the original function in a {@link Mockable | mockable} function.
+ * @remarks Use {@link mockify | `mockify.key`} as a convenient way to access this key.
+ */
+export const mockifyMockKey = Symbol("`mockify` mock function key");
+
+/**
+ * A function that can be mocked after being decorated by {@link mockify | mockify()}.
+ */
+export interface Mockable<T extends (...args: any[]) => unknown> {
+	(...args: Parameters<T>): ReturnType<T>;
+	[mockifyMockKey]: T;
+}
+
+/**
+ * Decorates a function to allow it to be mocked.
+ * @param fn - The function that will become mockable.
+ * @returns A function with a {@link mockifyMockKey | special property } that can be overwritten to mock the original function.
+ * By default, this property is set to the original function.
+ * If overwritten with a new function, the new function will be called instead of the original.
+ * @example
+ * ```typescript
+ * const original = () => console.log("original");
+ * const mockable = mockify(original);
+ * mockable(); // logs "original"
+ * mockable[mockify.key] = () => console.log("mocked");
+ * mockable(); // logs "mocked"
+ * mockable[mockify.key] = original;
+ * mockable(); // logs "original"
+ * ```
+ *
+ * This pattern is useful for mocking top-level exported functions in a module.
+ * For example,
+ * ```typescript
+ * export function fn() { /* ... * / }
+ * ```
+ * becomes
+ * ```typescript
+ * import { mockify } from "./mockify.js";
+ * export const fn = mockify(() => { /* ... * / });
+ * ```
+ * and can now be mocked by another module that imports it.
+ * ```typescript
+ * import * as sinon from "sinon";
+ * import { mockify } from "./mockify.js";
+ * import { fn } from "./module.js";
+ * sinon.stub(fn, mockify.key).callsFake(() => {
+ *   // ... mock function implementation ...
+ * });
+ * // ...
+ * sinon.restore();
+ * ```
+ */
+export function mockify<T extends (...args: any[]) => unknown>(fn: T): Mockable<T> {
+	const mockable = (...args: Parameters<T>): ReturnType<T> => {
+		return mockable[mockifyMockKey](...args) as ReturnType<T>;
+	};
+	mockable[mockifyMockKey] = fn;
+	return mockable;
+}
+
+mockify.key = mockifyMockKey;

packages/drivers/odsp-driver/src/odspUtils.ts

@@ -138,7 +138,7 @@ export async function fetchHelper(
 	const start = performanceNow();
 
 	// Node-fetch and dom have conflicting typing, force them to work by casting for now
-	return fetch(requestInfo, requestInit).then(
+	return fetchHelper.fetch(requestInfo, requestInit).then(
 		async (fetchResponse) => {
 			const response = fetchResponse as unknown as Response;
 			// Let's assume we can retry.
@@ -221,6 +221,8 @@ export async function fetchHelper(
 		},
 	);
 }
+// This allows `fetch` to be mocked (e.g. with sinon `stub()`)
+fetchHelper.fetch = fetch;
 
 /**
  * A utility function to fetch and parse as JSON with support for retries

packages/drivers/odsp-driver/src/socketModule.ts

@@ -5,6 +5,6 @@
 
 import { io } from "socket.io-client";
 
-// Import is required for side-effects.
-// eslint-disable-next-line unicorn/prefer-export-from
-export const SocketIOClientStatic = io;
+import { mockify, type Mockable } from "./mockify.js";
+
+export const SocketIOClientStatic: Mockable<typeof io> = mockify(io);

packages/drivers/odsp-driver/src/test/fetchSnapshot.spec.ts

@@ -25,8 +25,8 @@ import { convertToCompactSnapshot } from "../compactSnapshotWriter.js";
 import { HostStoragePolicyInternal } from "../contracts.js";
 import { createOdspUrl } from "../createOdspUrl.js";
 import { EpochTracker } from "../epochTracker.js";
-import * as fetchSnapshotImport from "../fetchSnapshot.js";
-import { ISnapshotRequestAndResponseOptions } from "../fetchSnapshot.js";
+import { downloadSnapshot, ISnapshotRequestAndResponseOptions } from "../fetchSnapshot.js";
+import { mockify } from "../mockify.js";
 import { LocalPersistentCache, NonPersistentCache } from "../odspCache.js";
 import { OdspDocumentStorageService } from "../odspDocumentStorageManager.js";
 import { OdspDriverUrlResolver } from "../odspDriverUrlResolver.js";
@@ -139,7 +139,7 @@ describe("Tests1 for snapshot fetch", () => {
 			_response: Promise<ISnapshotRequestAndResponseOptions>,
 			callback: () => Promise<T>,
 		): Promise<T> {
-			const getDownloadSnapshotStub = stub(fetchSnapshotImport, "downloadSnapshot");
+			const getDownloadSnapshotStub = stub(downloadSnapshot, mockify.key);
 			getDownloadSnapshotStub.returns(_response);
 			try {
 				return await callback();
@@ -181,7 +181,7 @@ describe("Tests1 for snapshot fetch", () => {
 			_response: Promise<ISnapshotRequestAndResponseOptions>,
 			callback: () => Promise<T>,
 		): Promise<T> {
-			const getDownloadSnapshotStub = stub(fetchSnapshotImport, "downloadSnapshot");
+			const getDownloadSnapshotStub = stub(downloadSnapshot, mockify.key);
 			getDownloadSnapshotStub.returns(_response);
 			try {
 				return await callback();
@@ -222,7 +222,7 @@ describe("Tests1 for snapshot fetch", () => {
 			_response: Promise<ISnapshotRequestAndResponseOptions>,
 			callback: () => Promise<T>,
 		): Promise<T> {
-			const getDownloadSnapshotStub = stub(fetchSnapshotImport, "downloadSnapshot");
+			const getDownloadSnapshotStub = stub(downloadSnapshot, mockify.key);
 			getDownloadSnapshotStub.returns(_response);
 			try {
 				return await callback();
@@ -270,7 +270,7 @@ describe("Tests1 for snapshot fetch", () => {
 			_response: Promise<ISnapshotRequestAndResponseOptions>,
 			callback: () => Promise<T>,
 		): Promise<T> {
-			const getDownloadSnapshotStub = stub(fetchSnapshotImport, "downloadSnapshot");
+			const getDownloadSnapshotStub = stub(downloadSnapshot, mockify.key);
 			getDownloadSnapshotStub.returns(_response);
 			try {
 				return await callback();
@@ -336,7 +336,7 @@ describe("Tests1 for snapshot fetch", () => {
 			_response: Promise<ISnapshotRequestAndResponseOptions>,
 			callback: () => Promise<T>,
 		): Promise<T> {
-			const getDownloadSnapshotStub = stub(fetchSnapshotImport, "downloadSnapshot");
+			const getDownloadSnapshotStub = stub(downloadSnapshot, mockify.key);
 			getDownloadSnapshotStub.returns(_response);
 			try {
 				return await callback();
@@ -401,7 +401,7 @@ describe("Tests1 for snapshot fetch", () => {
 			_response: Promise<ISnapshotRequestAndResponseOptions>,
 			callback: () => Promise<T>,
 		): Promise<T> {
-			const getDownloadSnapshotStub = stub(fetchSnapshotImport, "downloadSnapshot");
+			const getDownloadSnapshotStub = stub(downloadSnapshot, mockify.key);
 			getDownloadSnapshotStub.returns(_response);
 			try {
 				return await callback();
@@ -455,7 +455,7 @@ describe("Tests1 for snapshot fetch", () => {
 			_response: Promise<ISnapshotRequestAndResponseOptions>,
 			callback: () => Promise<T>,
 		): Promise<T> {
-			const getDownloadSnapshotStub = stub(fetchSnapshotImport, "downloadSnapshot");
+			const getDownloadSnapshotStub = stub(downloadSnapshot, mockify.key);
 			getDownloadSnapshotStub.returns(_response);
 			try {
 				return await callback();

packages/drivers/odsp-driver/src/test/joinSessionCacheTests.spec.ts

@@ -19,11 +19,12 @@ import { stub, type SinonStub } from "sinon";
 import { Socket } from "socket.io-client";
 
 import { createOdspUrl } from "../createOdspUrl.js";
+import { mockify } from "../mockify.js";
 import { OdspDocumentServiceFactory } from "../odspDocumentServiceFactory.js";
 import { OdspDriverUrlResolver } from "../odspDriverUrlResolver.js";
 import { getJoinSessionCacheKey } from "../odspUtils.js";
-import * as socketModule from "../socketModule.js";
-import * as joinSession from "../vroom.js";
+import { SocketIOClientStatic } from "../socketModule.js";
+import { fetchJoinSession } from "../vroom.js";
 
 // eslint-disable-next-line import/no-internal-modules
 import { ClientSocketMock } from "./socketTests/socketMock.js";
@@ -56,14 +57,14 @@ describe("expose joinSessionInfo Tests", () => {
 	);
 
 	function addJoinSessionStub(): SinonStub {
-		const joinSessionStub = stub(joinSession, "fetchJoinSession").callsFake(
+		const joinSessionStub = stub(fetchJoinSession, mockify.key).callsFake(
 			async () => joinSessionResponse,
 		);
 		return joinSessionStub;
 	}
 
 	async function mockSocket<T>(_response: Socket, callback: () => Promise<T>): Promise<T> {
-		const getSocketCreationStub = stub(socketModule, "SocketIOClientStatic");
+		const getSocketCreationStub = stub(SocketIOClientStatic, mockify.key);
 		getSocketCreationStub.returns(_response);
 		try {
 			return await callback();

packages/drivers/odsp-driver/src/test/joinSessionPeriodicCall.spec.ts

@@ -12,13 +12,14 @@ import { SinonFakeTimers, SinonStub, stub, useFakeTimers } from "sinon";
 
 import { OdspFluidDataStoreLocator } from "../contractsPublic.js";
 import { createOdspUrl } from "../createOdspUrl.js";
+import { mockify } from "../mockify.js";
 import { LocalPersistentCache } from "../odspCache.js";
 import * as odspDocumentDeltaConnection from "../odspDocumentDeltaConnection.js";
 import { OdspDocumentDeltaConnection } from "../odspDocumentDeltaConnection.js";
 import { OdspDocumentService } from "../odspDocumentService.js";
 import { OdspDocumentServiceFactory } from "../odspDocumentServiceFactory.js";
 import { OdspDriverUrlResolver } from "../odspDriverUrlResolver.js";
-import * as joinSession from "../vroom.js";
+import { fetchJoinSession } from "../vroom.js";
 
 describe("joinSessions Tests", () => {
 	let clock: SinonFakeTimers;
@@ -65,7 +66,7 @@ describe("joinSessions Tests", () => {
 
 	function addJoinSessionStub(time: number): SinonStub {
 		joinSessionResponse.refreshSessionDurationSeconds = time;
-		const joinSessionStub = stub(joinSession, "fetchJoinSession").callsFake(
+		const joinSessionStub = stub(fetchJoinSession, mockify.key).callsFake(
 			async () => joinSessionResponse,
 		);
 		return joinSessionStub;

packages/drivers/odsp-driver/src/test/localOdspDriver.spec.ts

@@ -5,6 +5,8 @@
 
 import { strict as assert } from "node:assert";
 import fs from "node:fs";
+import { dirname } from "node:path";
+import { fileURLToPath } from "node:url";
 
 import { IClient, SummaryType } from "@fluidframework/driver-definitions";
 import {
@@ -50,7 +52,7 @@ describe("Local Odsp driver", () => {
 	};
 
 	const localSnapshot = fs.readFileSync(
-		`${__dirname}/../../src/test/localSnapshots/localSnapshot1.json`,
+		`${getDirname()}/../../src/test/localSnapshots/localSnapshot1.json`,
 		{ encoding: "utf8" },
 	);
 
@@ -152,7 +154,7 @@ describe("Local Odsp driver", () => {
 
 		it("Delta storage service returns trailing ops", async () => {
 			const snapshotWithTrailingOps = fs.readFileSync(
-				`${__dirname}/../../src/test/localSnapshots/localSnapshot2.json`,
+				`${getDirname()}/../../src/test/localSnapshots/localSnapshot2.json`,
 				{ encoding: "utf8" },
 			);
 			const service = new LocalOdspDocumentService(
@@ -290,3 +292,10 @@ describe("Local Odsp driver", () => {
 		});
 	});
 });
+
+/**
+ * Retrieves the directory in which this module resides (equivalent to `__dirname` in CJS)
+ */
+function getDirname(): string {
+	return dirname(fileURLToPath(import.meta.url));
+}

packages/drivers/odsp-driver/src/test/mockFetch.ts

@@ -5,10 +5,11 @@
 
 import assert from "node:assert";
 
-import * as fetchModule from "node-fetch";
 import { Headers } from "node-fetch";
 import { stub } from "sinon";
 
+import { fetchHelper } from "../odspUtils.js";
+
 /**
  * Mock response returned by {@link createResponse}.
  */
@@ -49,14 +50,14 @@ export async function mockFetchMultiple<T>(
 	responses: (() => Promise<object>)[],
 	type: FetchCallType = "single",
 ): Promise<T> {
-	const fetchStub = stub(fetchModule, "default");
+	const fetchStub = stub(fetchHelper, "fetch");
 	fetchStub.callsFake(async () => {
 		if (type === "external") {
 			fetchStub.restore();
 		}
 		const cb = responses.shift();
 		assert(cb !== undefined, "the end");
-		return cb() as Promise<fetchModule.Response>;
+		return cb() as Promise<Response>;
 	});
 	try {
 		return await callback();
@@ -89,7 +90,7 @@ export async function mockFetchError<T>(
 	response: Error,
 	type: FetchCallType = "single",
 ): Promise<T> {
-	const fetchStub = stub(fetchModule, "default");
+	const fetchStub = stub(fetchHelper, "fetch");
 	fetchStub.callsFake(async () => {
 		if (type === "external") {
 			fetchStub.restore();

packages/drivers/odsp-driver/src/test/odspDriverUrlResolverForShareLink.spec.ts

@@ -14,7 +14,8 @@ import { stub } from "sinon";
 import { SharingLinkHeader } from "../contractsPublic.js";
 import { createOdspCreateContainerRequest } from "../createOdspCreateContainerRequest.js";
 import { createOdspUrl } from "../createOdspUrl.js";
-import * as fileLinkImport from "../getFileLink.js";
+import { getFileLink } from "../getFileLink.js";
+import { mockify } from "../mockify.js";
 import { OdspDriverUrlResolverForShareLink } from "../odspDriverUrlResolverForShareLink.js";
 import {
 	getLocatorFromOdspUrl,
@@ -80,7 +81,7 @@ describe("Tests for OdspDriverUrlResolverForShareLink resolver", () => {
 		response: Promise<string>,
 		callback: () => Promise<T>,
 	): Promise<T> {
-		const getFileLinkStub = stub(fileLinkImport, "getFileLink");
+		const getFileLinkStub = stub(getFileLink, mockify.key);
 		getFileLinkStub.returns(response);
 		try {
 			return await callback();