Add test

lib/msal-node/test/cache/TokenCache.spec.ts

@@ -7,7 +7,7 @@ import {
 } from "@azure/msal-common";
 import { NodeStorage } from "../../src/cache/NodeStorage";
 import { TokenCache } from "../../src/cache/TokenCache";
-import { promises as fs } from "fs";
+import { existsSync, watch, promises, FSWatcher } from "fs";
 import { version, name } from "../../package.json";
 import {
     DEFAULT_CRYPTO_IMPLEMENTATION,
@@ -24,6 +24,7 @@ const msalCommon: MSALCommonModule = jest.requireActual(
 describe("TokenCache tests", () => {
     let logger: Logger;
     let storage: NodeStorage;
+    let watcher: FSWatcher;
 
     beforeEach(() => {
         const loggerOptions = {
@@ -50,6 +51,12 @@ describe("TokenCache tests", () => {
         jest.restoreAllMocks();
     });
 
+    afterEach(() => {
+        if (watcher) {
+            watcher.close();
+        }
+    });
+
     it("Constructor tests builds default token cache", async () => {
         const tokenCache = new TokenCache(storage, logger);
         expect(tokenCache).toBeInstanceOf(TokenCache);
@@ -115,15 +122,15 @@ describe("TokenCache tests", () => {
     it("TokenCache beforeCacheAccess and afterCacheAccess", async () => {
         const beforeCacheAccess = async (context: TokenCacheContext) => {
             context.tokenCache.deserialize(
-                await fs.readFile(
+                await promises.readFile(
                     "./test/cache/cache-test-files/cache-unrecognized-entities.json",
                     "utf-8"
                 )
             );
         };
         const cachePath = "./test/cache/cache-test-files/temp-cache.json";
         const afterCacheAccess = async (context: TokenCacheContext) => {
-            await fs.writeFile(cachePath, context.tokenCache.serialize());
+            await promises.writeFile(cachePath, context.tokenCache.serialize());
         };
 
         const cachePlugin: ICachePlugin = {
@@ -153,7 +160,7 @@ describe("TokenCache tests", () => {
 
         // try and clean up
         try {
-            await fs.unlink(cachePath);
+            await promises.unlink(cachePath);
         } catch (err) {
             const errnoException = err as NodeJS.ErrnoException;
             if (errnoException.code == "ENOENT") {
@@ -164,6 +171,50 @@ describe("TokenCache tests", () => {
         }
     });
 
+    it("getAllAccounts doesn't write to cache", async () => {
+        const cachePath =
+            "./test/cache/cache-test-files/cache-unrecognized-entities.json";
+        if (existsSync(cachePath)) {
+            watcher = watch(cachePath, (eventType: string) => {
+                if (eventType === "change") {
+                    throw new Error("test cache changed");
+                }
+            });
+        } else {
+            throw new Error("error in watching test cache");
+        }
+
+        const beforeCacheAccess = jest.fn(
+            async (context: TokenCacheContext) => {
+                if (context.hasChanged == true) {
+                    throw new Error("hasChanged should be false");
+                }
+                return promises.readFile(cachePath, "utf-8").then((data) => {
+                    context.tokenCache.deserialize(data);
+                });
+            }
+        );
+
+        const afterCacheAccess = jest.fn(async (context: TokenCacheContext) => {
+            if (context.hasChanged == true) {
+                throw new Error("hasChanged should be false");
+            }
+            return Promise.resolve();
+        });
+
+        const cachePlugin: ICachePlugin = {
+            beforeCacheAccess,
+            afterCacheAccess,
+        };
+
+        const tokenCache = new TokenCache(storage, logger, cachePlugin);
+
+        const accounts = await tokenCache.getAllAccounts();
+        expect(accounts.length).toBe(1);
+        expect(beforeCacheAccess).toHaveBeenCalled();
+        expect(afterCacheAccess).toHaveBeenCalled();
+    });
+
     it("should return an empty KV store if TokenCache is empty", () => {
         const tokenCache = new TokenCache(storage, logger);