FFM-11972 Add authRequestReadTimeout option (#135)

Author: erdirowlands

README.md

@@ -330,6 +330,54 @@ interface Evaluation {
 }
 ```
 
+## Authentication Request Timeout
+
+The `authRequestReadTimeout` option allows you to specify a timeout in milliseconds for the authentication request. If the request takes longer than this timeout, it will be aborted. This is useful for preventing hanging requests due to network issues or slow responses.
+
+If the request is aborted due to this timeout the SDK will fail to initialize and an `ERROR_AUTH` and `ERROR` event will be emitted.
+
+**This only applies to the authentiaction request. If you wish to set a read timeout on the remaining requests made by the SDK, you may register [API Middleware](#api-middleware)
+
+```typescript
+const options = {
+  authRequestReadTimeout: 30000, // Timeout in milliseconds (default: 30000)
+};
+
+const client = initialize(
+  'YOUR_API_KEY',
+  {
+    identifier: 'Harness1',
+    attributes: {
+      lastUpdated: Date(),
+      host: location.href,
+    },
+  },
+  options
+);
+```
+
+## API Middleware
+The `registerAPIRequestMiddleware` function allows you to register a middleware function to manipulate the payload (URL, body and headers) of API requests after the AUTH call has successfully completed
+
+```typescript
+function abortControllerMiddleware([url, options]) {
+  if (window.AbortController) {
+    const abortController = new AbortController();
+    options.signal = abortController.signal;
+
+    // Set a timeout to automatically abort the request after 30 seconds
+    setTimeout(() => abortController.abort(), 30000);
+  }
+
+  return [url, options]; // Return the modified or original arguments
+}
+
+// Register the middleware
+client.registerAPIRequestMiddleware(abortControllerMiddleware);
+```
+This example middleware will automatically attach an AbortController to each request, which will abort the request if it takes longer than the specified timeout. You can also customize the middleware to perform other actions, such as logging or modifying headers.
+
+
 ## Logging
 By default, the Javascript Client SDK will log errors and debug messages using the `console` object. In some cases, it
 can be useful to instead log to a service or silently fail without logging errors.

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "@harnessio/ff-javascript-client-sdk",
-  "version": "1.27.0",
+  "version": "1.28.0",
   "author": "Harness",
   "license": "Apache-2.0",
   "main": "dist/sdk.cjs.js",

package.json

@@ -3,7 +3,7 @@ import type { Options } from '../types'
 import { Event } from '../types'
 import { getRandom } from '../utils'
 import type { Emitter } from 'mitt'
-import type Poller from "../poller";
+import type Poller from '../poller'
 
 jest.useFakeTimers()
 
@@ -49,16 +49,16 @@ const getStreamer = (overrides: Partial<Options> = {}, maxRetries: number = Infi
   }
 
   return new Streamer(
-      mockEventBus,
-      options,
-      `${options.baseUrl}/stream`,
-      'test-api-key',
-      { 'Test-Header': 'value' },
-      { start: jest.fn(), stop: jest.fn(), isPolling: jest.fn() } as unknown as Poller,
-      logDebug,
-      logError,
-      jest.fn(),
-      maxRetries
+    mockEventBus,
+    options,
+    `${options.baseUrl}/stream`,
+    'test-api-key',
+    { 'Test-Header': 'value' },
+    { start: jest.fn(), stop: jest.fn(), isPolling: jest.fn() } as unknown as Poller,
+    logDebug,
+    logError,
+    jest.fn(),
+    maxRetries
   )
 }
 
@@ -130,16 +130,16 @@ describe('Streamer', () => {
   it('should fallback to polling on stream failure', () => {
     const poller = { start: jest.fn(), stop: jest.fn(), isPolling: jest.fn() } as unknown as Poller
     const streamer = new Streamer(
-        mockEventBus,
-        { baseUrl: 'http://test', eventUrl: 'http://event', pollingEnabled: true, streamEnabled: true, debug: true },
-        'http://test/stream',
-        'test-api-key',
-        { 'Test-Header': 'value' },
-        poller,
-        logDebug,
-        logError,
-        jest.fn(),
-        Infinity
+      mockEventBus,
+      { baseUrl: 'http://test', eventUrl: 'http://event', pollingEnabled: true, streamEnabled: true, debug: true },
+      'http://test/stream',
+      'test-api-key',
+      { 'Test-Header': 'value' },
+      poller,
+      logDebug,
+      logError,
+      jest.fn(),
+      Infinity
     )
 
     streamer.start()
@@ -154,21 +154,19 @@ describe('Streamer', () => {
 
   it('should stop polling when close is called if in fallback polling mode', () => {
     const poller = { start: jest.fn(), stop: jest.fn(), isPolling: jest.fn() } as unknown as Poller
-    ;(poller.isPolling as jest.Mock)
-        .mockImplementationOnce(() => false)
-        .mockImplementationOnce(() => true)
+    ;(poller.isPolling as jest.Mock).mockImplementationOnce(() => false).mockImplementationOnce(() => true)
 
     const streamer = new Streamer(
-        mockEventBus,
-        { baseUrl: 'http://test', eventUrl: 'http://event', pollingEnabled: true, streamEnabled: true, debug: true },
-        'http://test/stream',
-        'test-api-key',
-        { 'Test-Header': 'value' },
-        poller,
-        logDebug,
-        logError,
-        jest.fn(),
-        3
+      mockEventBus,
+      { baseUrl: 'http://test', eventUrl: 'http://event', pollingEnabled: true, streamEnabled: true, debug: true },
+      'http://test/stream',
+      'test-api-key',
+      { 'Test-Header': 'value' },
+      poller,
+      logDebug,
+      logError,
+      jest.fn(),
+      3
     )
 
     streamer.start()
@@ -190,18 +188,22 @@ describe('Streamer', () => {
   })
 
   it('should stop streaming but not call poller.stop if not in fallback polling mode when close is called', () => {
-    const poller = { start: jest.fn(), stop: jest.fn(), isPolling: jest.fn().mockReturnValue(false) } as unknown as Poller
+    const poller = {
+      start: jest.fn(),
+      stop: jest.fn(),
+      isPolling: jest.fn().mockReturnValue(false)
+    } as unknown as Poller
     const streamer = new Streamer(
-        mockEventBus,
-        { baseUrl: 'http://test', eventUrl: 'http://event', pollingEnabled: true, streamEnabled: true, debug: true },
-        'http://test/stream',
-        'test-api-key',
-        { 'Test-Header': 'value' },
-        poller,
-        logDebug,
-        logError,
-        jest.fn(),
-        3
+      mockEventBus,
+      { baseUrl: 'http://test', eventUrl: 'http://event', pollingEnabled: true, streamEnabled: true, debug: true },
+      'http://test/stream',
+      'test-api-key',
+      { 'Test-Header': 'value' },
+      poller,
+      logDebug,
+      logError,
+      jest.fn(),
+      3
     )
 
     streamer.start()

src/__tests__/stream.test.ts

@@ -64,6 +64,10 @@ const initialize = (apiKey: string, target: Target, options?: Options): Result =
     configurations.logger.error(`[FF-SDK] ${message}`, ...args)
   }
 
+  const logWarn = (message: string, ...args: any[]) => {
+    configurations.logger.warn(`[FF-SDK] ${message}`, ...args)
+  }
+
   const convertValue = (evaluation: Evaluation) => {
     let { value } = evaluation
 
@@ -143,18 +147,50 @@ const initialize = (apiKey: string, target: Target, options?: Options): Result =
   }
 
   const authenticate = async (clientID: string, configuration: Options): Promise<string> => {
-    const response = await fetch(`${configuration.baseUrl}/client/auth`, {
+    const url = `${configuration.baseUrl}/client/auth`
+    const requestOptions: RequestInit = {
       method: 'POST',
       headers: { 'Content-Type': 'application/json', 'Harness-SDK-Info': SDK_INFO },
       body: JSON.stringify({
         apiKey: clientID,
         target: { ...target, identifier: String(target.identifier) }
       })
-    })
+    }
+
+    let timeoutId: number | undefined
+    let abortController: AbortController | undefined
 
-    const data: { authToken: string } = await response.json()
+    if (window.AbortController && configurations.authRequestReadTimeout > 0) {
+      abortController = new AbortController()
+      requestOptions.signal = abortController.signal
+
+      timeoutId = window.setTimeout(() => abortController.abort(), configuration.authRequestReadTimeout)
+    } else if (configuration.authRequestReadTimeout > 0) {
+      logWarn('AbortController is not available, auth request will not timeout')
+    }
+
+    try {
+      const response = await fetch(url, requestOptions)
 
-    return data.authToken
+      if (!response.ok) {
+        throw new Error(`${response.status}: ${response.statusText}`)
+      }
+
+      const data: { authToken: string } = await response.json()
+      return data.authToken
+    } catch (error) {
+      if (abortController && abortController.signal.aborted) {
+        throw new Error(
+          `Request to ${url} failed: Request timeout via configured authRequestTimeout of ${configurations.authRequestReadTimeout}`
+        )
+      }
+      const errorMessage = error instanceof Error ? error.message : String(error)
+      throw new Error(`Request to ${url} failed: ${errorMessage}`)
+    } finally {
+      if (timeoutId) {
+        clearTimeout(timeoutId)
+      }
+    }
   }
 
   let failedMetricsCallCount = 0

src/index.ts

@@ -133,6 +133,12 @@ export interface Options {
    * Whether to enable debug logging.
    * @default false
    */
+  authRequestReadTimeout?: number
+  /**
+   * The timeout in milliseconds for the authentication request to read the response.
+   * If the request takes longer than this timeout, it will be aborted and the SDK will fail to initialize, and `ERROR_AUTH` and `ERROR` events will be emitted.
+   * @default 0 (no timeout)
+   */
   debug?: boolean
   /**
    * Whether to enable caching.

src/types.ts

@@ -11,6 +11,7 @@ export const defaultOptions: Options = {
   pollingInterval: MIN_POLLING_INTERVAL,
   streamEnabled: true,
   cache: false,
+  authRequestReadTimeout: 0,
   maxStreamRetries: Infinity
 }