Minor improvements (#92)

* Improve base64 decode perf. + add tests + fix code formatting

* Use LocalStorageCache only when localStorage is available + don't swallow exceptions in LocalStorageCache.get/set

* Escape ccetag query string value

* Exclude non-source files so they don't pollute autocompletion/intellisense

* Update to configcat-common v9.1.0

* Bump version

package.json

@@ -1,6 +1,6 @@
 {
   "name": "configcat-js",
-  "version": "9.2.0",
+  "version": "9.3.0",
   "description": "ConfigCat is a configuration as a service that lets you manage your features and configurations without actually deploying new code.",
   "main": "lib/index.js",
   "types": "lib/index.d.ts",
@@ -33,7 +33,7 @@
   "license": "MIT",
   "homepage": "https://configcat.com",
   "dependencies": {
-    "configcat-common": "^9.0.0",
+    "configcat-common": "^9.1.0",
     "tslib": "^2.4.1"
   },
   "devDependencies": {

src/Cache.ts

@@ -1,37 +1,58 @@
-import type { IConfigCatCache } from "configcat-common";
+import type { IConfigCatCache, IConfigCatKernel } from "configcat-common";
+import { ExternalConfigCache } from "configcat-common";
 
 export class LocalStorageCache implements IConfigCatCache {
-  set(key: string, value: string): void {
-    try {
-      localStorage.setItem(key, this.b64EncodeUnicode(value));
-    }
-    catch (ex) {
-      // local storage is unavailable
+  static setup(kernel: IConfigCatKernel, localStorageGetter?: () => Storage | null): IConfigCatKernel {
+    const localStorage = (localStorageGetter ?? getLocalStorage)();
+    if (localStorage) {
+      kernel.defaultCacheFactory = options => new ExternalConfigCache(new LocalStorageCache(localStorage), options.logger);
     }
+    return kernel;
+  }
+
+  constructor(private readonly storage: Storage) {
+  }
+
+  set(key: string, value: string): void {
+    this.storage.setItem(key, toUtf8Base64(value));
   }
 
   get(key: string): string | undefined {
-    try {
-      const configString = localStorage.getItem(key);
-      if (configString) {
-        return this.b64DecodeUnicode(configString);
-      }
+    const configString = this.storage.getItem(key);
+    if (configString) {
+      return fromUtf8Base64(configString);
     }
-    catch (ex) {
-      // local storage is unavailable or invalid cache value in localstorage
-    }
-    return void 0;
   }
+}
 
-  private b64EncodeUnicode(str: string): string {
-    return btoa(encodeURIComponent(str).replace(/%([0-9A-F]{2})/g, function (_, p1) {
-      return String.fromCharCode(parseInt(p1, 16))
-    }));
-  }
+export function getLocalStorage(): Storage | null {
+  const testKey = "__configcat_localStorage_test";
+
+  try {
+    const storage = window.localStorage;
+    storage.setItem(testKey, testKey);
+
+    let retrievedItem: string | null;
+    try { retrievedItem = storage.getItem(testKey); }
+    finally { storage.removeItem(testKey); }
 
-  private b64DecodeUnicode(str: string): string {
-    return decodeURIComponent(Array.prototype.map.call(atob(str), function (c: string) {
-      return '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2)
-    }).join(''));
+    if (retrievedItem === testKey) {
+      return storage;
+    }
   }
+  catch (err) { /* intentional no-op */ }
+
+  return null;
+}
+
+export function toUtf8Base64(str: string): string {
+  str = encodeURIComponent(str);
+  str = str.replace(/%([0-9A-F]{2})/g, (_, p1) => String.fromCharCode(parseInt(p1, 16)));
+  return btoa(str);
+}
+
+export function fromUtf8Base64(str: string): string {
+  str = atob(str);
+  str = str.replace(/[%\x80-\xFF]/g, m => "%" + m.charCodeAt(0).toString(16));
+  return decodeURIComponent(str);
 }

src/ConfigFetcher.ts

@@ -38,7 +38,7 @@ export class HttpConfigFetcher implements IConfigFetcher {
         let url = options.getUrl();
         if (lastEtag) {
           // We are sending the etag as a query parameter so if the browser doesn't automatically adds the If-None-Match header, we can transorm this query param to the header in our CDN provider.
-          url += '&ccetag=' + lastEtag;
+          url += "&ccetag=" + encodeURIComponent(lastEtag);
         }
         httpRequest.open("GET", url, true);
         httpRequest.timeout = options.requestTimeoutMs;

src/index.ts

@@ -1,5 +1,5 @@
 import type { IAutoPollOptions, IConfigCatClient, IConfigCatLogger, ILazyLoadingOptions, IManualPollOptions, LogLevel, OverrideBehaviour, SettingValue } from "configcat-common";
-import { ExternalConfigCache, FlagOverrides, MapOverrideDataSource, PollingMode } from "configcat-common";
+import { FlagOverrides, MapOverrideDataSource, PollingMode } from "configcat-common";
 import * as configcatcommon from "configcat-common";
 import { LocalStorageCache } from "./Cache";
 import { HttpConfigFetcher } from "./ConfigFetcher";
@@ -17,12 +17,11 @@ import CONFIGCAT_SDK_VERSION from "./Version";
  */
 export function getClient<TMode extends PollingMode | undefined>(sdkKey: string, pollingMode?: TMode, options?: OptionsForPollingMode<TMode>): IConfigCatClient {
   return configcatcommon.getClient(sdkKey, pollingMode ?? PollingMode.AutoPoll, options,
-    {
+    LocalStorageCache.setup({
       configFetcher: new HttpConfigFetcher(),
       sdkType: "ConfigCat-JS",
       sdkVersion: CONFIGCAT_SDK_VERSION,
-      defaultCacheFactory: options => new ExternalConfigCache(new LocalStorageCache(), options.logger)
-    });
+    }));
 }
 
 /**

test/CacheTests.ts

@@ -1,14 +1,84 @@
 import { assert } from "chai";
-import { LocalStorageCache } from "../lib/Cache";
+import { LogLevel } from "configcat-common";
+import { LocalStorageCache, fromUtf8Base64, getLocalStorage, toUtf8Base64 } from "../src/Cache";
+import { FakeLogger } from "./helpers/fakes";
+import { createClientWithLazyLoad } from "./helpers/utils";
 
+describe("Base64 encode/decode test", () => {
+  let allBmpChars = "";
+  for (let i = 0; i <= 0xFFFF; i++) {
+    if (i < 0xD800 || 0xDFFF < i) { // skip lone surrogate chars
+      allBmpChars += String.fromCharCode(i);
+    }
+  }
 
-describe("LocalStorageCache cache tests", () => {
-    it("LocalStorageCache works with non latin 1 characters", () => {
-        const cache = new LocalStorageCache();
-        const key = "testkey";
-        const text = "äöüÄÖÜçéèñışğ⢙✓😀";
-        cache.set(key, text);
-        const retrievedValue = cache.get(key);
-        assert.strictEqual(retrievedValue, text);
+  for (const input of [
+    "",
+    "\n",
+    "äöüÄÖÜçéèñışğ⢙✓😀",
+    allBmpChars
+  ]) {
+    it(`Base64 encode/decode works - input: ${input.slice(0, Math.min(input.length, 128))}`, () => {
+      assert.strictEqual(fromUtf8Base64(toUtf8Base64(input)), input);
     });
+  }
+});
+
+describe("LocalStorageCache cache tests", () => {
+  it("LocalStorageCache works with non latin 1 characters", () => {
+    const localStorage = getLocalStorage();
+    assert.isNotNull(localStorage);
+
+    const cache = new LocalStorageCache(localStorage!);
+    const key = "testkey";
+    const text = "äöüÄÖÜçéèñışğ⢙✓😀";
+    cache.set(key, text);
+    const retrievedValue = cache.get(key);
+    assert.strictEqual(retrievedValue, text);
+    assert.strictEqual(window.localStorage.getItem(key), "w6TDtsO8w4TDlsOcw6fDqcOow7HEscWfxJ/DosKi4oSi4pyT8J+YgA==");
+  });
+
+  it("Error is logged when LocalStorageCache.get throws", async () => {
+    const errorMessage = "Something went wrong.";
+    const faultyLocalStorage: Storage = {
+      get length() { return 0; },
+      clear() { },
+      getItem() { throw Error(errorMessage); },
+      setItem() { },
+      removeItem() { },
+      key() { return null; }
+    };
+
+    const fakeLogger = new FakeLogger();
+
+    const client = createClientWithLazyLoad("configcat-sdk-1/PKDVCLf-Hq-h-kCzMp-L7Q/AG6C1ngVb0CvM07un6JisQ", { logger: fakeLogger },
+      kernel => LocalStorageCache.setup(kernel, () => faultyLocalStorage));
+
+    try { await client.getValueAsync("stringDefaultCat", ""); }
+    finally { client.dispose(); }
+
+    assert.isDefined(fakeLogger.events.find(([level, eventId, , err]) => level === LogLevel.Error && eventId === 2200 && err instanceof Error && err.message === errorMessage));
+  });
+
+  it("Error is logged when LocalStorageCache.set throws", async () => {
+    const errorMessage = "Something went wrong.";
+    const faultyLocalStorage: Storage = {
+      get length() { return 0; },
+      clear() { },
+      getItem() { return null; },
+      setItem() { throw Error(errorMessage); },
+      removeItem() { },
+      key() { return null; }
+    };
+
+    const fakeLogger = new FakeLogger();
+
+    const client = createClientWithLazyLoad("configcat-sdk-1/PKDVCLf-Hq-h-kCzMp-L7Q/AG6C1ngVb0CvM07un6JisQ", { logger: fakeLogger },
+      kernel => LocalStorageCache.setup(kernel, () => faultyLocalStorage));
+
+    try { await client.getValueAsync("stringDefaultCat", ""); }
+    finally { client.dispose(); }
+
+    assert.isDefined(fakeLogger.events.find(([level, eventId, , err]) => level === LogLevel.Error && eventId === 2201 && err instanceof Error && err.message === errorMessage));
+  });
 });

test/HttpTests.ts

@@ -33,7 +33,7 @@ describe("HTTP tests", () => {
       const defaultValue = "NOT_CAT";
       assert.strictEqual(defaultValue, await client.getValueAsync("stringDefaultCat", defaultValue));
 
-      assert.isDefined(logger.messages.find(([level, msg]) => level === LogLevel.Error && msg.startsWith("Request timed out while trying to fetch config JSON.")));
+      assert.isDefined(logger.events.find(([level, , msg]) => level === LogLevel.Error && msg.toString().startsWith("Request timed out while trying to fetch config JSON.")));
     }
     finally {
       server.remove();
@@ -61,7 +61,7 @@ describe("HTTP tests", () => {
       const defaultValue = "NOT_CAT";
       assert.strictEqual(defaultValue, await client.getValueAsync("stringDefaultCat", defaultValue));
 
-      assert.isDefined(logger.messages.find(([level, msg]) => level === LogLevel.Error && msg.startsWith("Your SDK Key seems to be wrong.")));
+      assert.isDefined(logger.events.find(([level, , msg]) => level === LogLevel.Error && msg.toString().startsWith("Your SDK Key seems to be wrong.")));
     }
     finally {
       server.remove();
@@ -89,7 +89,7 @@ describe("HTTP tests", () => {
       const defaultValue = "NOT_CAT";
       assert.strictEqual(defaultValue, await client.getValueAsync("stringDefaultCat", defaultValue));
 
-      assert.isDefined(logger.messages.find(([level, msg]) => level === LogLevel.Error && msg.startsWith("Unexpected HTTP response was received while trying to fetch config JSON:")));
+      assert.isDefined(logger.events.find(([level, , msg]) => level === LogLevel.Error && msg.toString().startsWith("Unexpected HTTP response was received while trying to fetch config JSON:")));
     }
     finally {
       server.remove();
@@ -117,9 +117,7 @@ describe("HTTP tests", () => {
       const defaultValue = "NOT_CAT";
       assert.strictEqual(defaultValue, await client.getValueAsync("stringDefaultCat", defaultValue));
 
-      console.log(logger.messages);
-
-      assert.isDefined(logger.messages.find(([level, msg]) => level === LogLevel.Error && msg.startsWith("Unexpected error occurred while trying to fetch config JSON.")));
+      assert.isDefined(logger.events.find(([level, , msg]) => level === LogLevel.Error && msg.toString().startsWith("Unexpected error occurred while trying to fetch config JSON.")));
     }
     finally {
       server.remove();

test/SpecialCharacterTests.ts

@@ -1,31 +1,31 @@
 import { assert } from "chai";
-import { IConfigCatClient, IEvaluationDetails, IOptions, LogLevel, PollingMode, SettingKeyValue, User } from "configcat-common";
+import { IConfigCatClient, IOptions, LogLevel, PollingMode, User } from "configcat-common";
 import * as configcatClient from "../src";
 import { createConsoleLogger } from "../src";
 
 const sdkKey = "configcat-sdk-1/PKDVCLf-Hq-h-kCzMp-L7Q/u28_1qNyZ0Wz-ldYHIU7-g";
 
 describe("Special characters test", () => {
 
-    const options: IOptions = { logger: createConsoleLogger(LogLevel.Off) };
+  const options: IOptions = { logger: createConsoleLogger(LogLevel.Off) };
 
-    let client: IConfigCatClient;
+  let client: IConfigCatClient;
 
-    beforeEach(function () {
-        client = configcatClient.getClient(sdkKey, PollingMode.AutoPoll, options);
-    });
+  beforeEach(function() {
+    client = configcatClient.getClient(sdkKey, PollingMode.AutoPoll, options);
+  });
 
-    afterEach(function () {
-        client.dispose();
-    });
+  afterEach(function() {
+    client.dispose();
+  });
 
-    it(`Special characters works - cleartext`, async () => {
-        const actual: string = await client.getValueAsync("specialCharacters", "NOT_CAT", new User("äöüÄÖÜçéèñışğ⢙✓😀"));
-        assert.strictEqual(actual, "äöüÄÖÜçéèñışğ⢙✓😀");
-    });
+  it("Special characters works - cleartext", async () => {
+    const actual: string = await client.getValueAsync("specialCharacters", "NOT_CAT", new User("äöüÄÖÜçéèñışğ⢙✓😀"));
+    assert.strictEqual(actual, "äöüÄÖÜçéèñışğ⢙✓😀");
+  });
 
-    it(`Special characters works - hashed`, async () => {
-        const actual: string = await client.getValueAsync("specialCharactersHashed", "NOT_CAT", new User("äöüÄÖÜçéèñışğ⢙✓😀"));
-        assert.strictEqual(actual, "äöüÄÖÜçéèñışğ⢙✓😀");
-    });
+  it("Special characters works - hashed", async () => {
+    const actual: string = await client.getValueAsync("specialCharactersHashed", "NOT_CAT", new User("äöüÄÖÜçéèñışğ⢙✓😀"));
+    assert.strictEqual(actual, "äöüÄÖÜçéèñışğ⢙✓😀");
+  });
 });

test/helpers/fakes.ts

@@ -1,13 +1,13 @@
 import { IConfigCatLogger, LogEventId, LogLevel, LogMessage } from "../../src";
 
 export class FakeLogger implements IConfigCatLogger {
-  messages: [LogLevel, string][] = [];
+  events: [LogLevel, LogEventId, LogMessage, any?][] = [];
 
   constructor(public level = LogLevel.Info) { }
 
-  reset(): void { this.messages.splice(0); }
+  reset(): void { this.events.splice(0); }
 
   log(level: LogLevel, eventId: LogEventId, message: LogMessage, exception?: any): void {
-    this.messages.push([level, message.toString()]);
+    this.events.push([level, eventId, message, exception]);
   }
 }