Add total timeout configuration option

Author: mironov

README.md

@@ -72,9 +72,11 @@ The following object shows the default options:
   maxDelay: 0,
   factor: 0,
   timeout: 0,
+  totalTimeout: 0,
   jitter: false,
   handleError: null,
   handleTimeout: null,
+  handleTotalTimeout: null,
   beforeAttempt: null,
   calculateDelay: null
 }
@@ -143,6 +145,17 @@ to your target environment.
 
   (default: `0`)
 
+- **`totalTimeout`**: `Number`
+
+  A total timeout for all attempts in milliseconds. If `totalTimeout` is
+  non-zero then a timer is set using `setTimeout`. If the timeout is
+  triggered then future attempts will be aborted.
+
+  The `handleTotalTimeout` function can be used to implement fallback
+  functionality.
+
+  (default: `0`)
+
 - **`jitter`**: `Boolean`
 
   If `jitter` is `true` then the calculated delay will
@@ -175,6 +188,12 @@ to your target environment.
   `timeout`. The `handleTimeout` function should return a `Promise`
   that will be the return value of the `retry()` function.
 
+- **`handleTotalTimeout`**: `(options) => Promise | void`
+
+  `handleTotalTimeout` is invoked if a timeout occurs when using a non-zero
+  `totalTimeout`. The `handleTotalTimeout` function should return a `Promise`
+  that will be the return value of the `retry()` function.
+
 - **`beforeAttempt`**: `(context, options) => void`
 
   The `beforeAttempt` function is invoked before each attempt.
@@ -339,3 +358,43 @@ const result = await retry(async function() {
   }
 });
 ```
+
+### Stop retrying if there is a total timeout
+
+```js
+// Try the given operation up to 5 times. The initial delay will be 0
+// and subsequent delays will be 200, 400, 800, 1600.
+//
+// If the given async function fails to complete after 1 second then the
+// retries are aborted and error with `code` `TOTAL_TIMEOUT` is thrown.
+const result = await retry(async function() {
+  // do something that returns a promise
+}, {
+  delay: 200,
+  factor: 2,
+  maxAttempts: 5,
+  totalTimeout: 1000
+});
+```
+
+### Stop retrying if there is a total timeout but provide a fallback
+
+```js
+// Try the given operation up to 5 times. The initial delay will be 0
+// and subsequent delays will be 200, 400, 800, 1600.
+//
+// If the given async function fails to complete after 1 second then the
+// retries are aborted and the `handleTotalTimeout` implements some fallback
+// logic.
+const result = await retry(async function() {
+  // do something that returns a promise
+}, {
+  delay: 200,
+  factor: 2,
+  maxAttempts: 5,
+  totalTimeout: 1000,
+  async handleTotalTimeout (options) {
+    // do something that returns a promise or throw your own error
+  }
+});
+```

src/index.ts

@@ -10,6 +10,7 @@ export type BeforeAttempt<T> = (context: AttemptContext, options: AttemptOptions
 export type CalculateDelay<T> = (context: AttemptContext, options: AttemptOptions<T>) => number;
 export type HandleError<T> = (err: any, context: AttemptContext, options: AttemptOptions<T>) => void;
 export type HandleTimeout<T> = (context: AttemptContext, options: AttemptOptions<T>) => Promise<T>;
+export type HandleTotalTimeout<T> = (options: AttemptOptions<T>) => Promise<T>;
 
 export interface AttemptOptions<T> {
   readonly delay: number;
@@ -19,9 +20,11 @@ export interface AttemptOptions<T> {
   readonly factor: number;
   readonly maxAttempts: number;
   readonly timeout: number;
+  readonly totalTimeout: number;
   readonly jitter: boolean;
   readonly handleError: HandleError<T> | null;
   readonly handleTimeout: HandleTimeout<T> | null;
+  readonly handleTotalTimeout: HandleTotalTimeout<T> | null;
   readonly beforeAttempt: BeforeAttempt<T> | null;
   readonly calculateDelay: CalculateDelay<T> | null;
 }
@@ -43,9 +46,11 @@ function applyDefaults<T> (options?: PartialAttemptOptions<T>): AttemptOptions<T
     factor: (options.factor === undefined) ? 0 : options.factor,
     maxAttempts: (options.maxAttempts === undefined) ? 3 : options.maxAttempts,
     timeout: (options.timeout === undefined) ? 0 : options.timeout,
+    totalTimeout: (options.totalTimeout === undefined) ? 0 : options.totalTimeout,
     jitter: (options.jitter === true),
     handleError: (options.handleError === undefined) ? null : options.handleError,
     handleTimeout: (options.handleTimeout === undefined) ? null : options.handleTimeout,
+    handleTotalTimeout: (options.handleTotalTimeout === undefined) ? null : options.handleTotalTimeout,
     beforeAttempt: (options.beforeAttempt === undefined) ? null : options.beforeAttempt,
     calculateDelay: (options.calculateDelay === undefined) ? null : options.calculateDelay
   };
@@ -88,7 +93,7 @@ export function defaultCalculateDelay<T> (context: AttemptContext, options: Atte
 
 export async function retry<T> (
   attemptFunc: AttemptFunction<T>,
-  attemptOptions?: PartialAttemptOptions<T>): Promise<T> {
+  attemptOptions?: PartialAttemptOptions<T>): Promise<any> {
 
   const options = applyDefaults(attemptOptions);
 
@@ -98,7 +103,8 @@ export async function retry<T> (
     'minDelay',
     'maxDelay',
     'maxAttempts',
-    'timeout'
+    'timeout',
+    'totalTimeout'
   ]) {
     const value: any = (options as any)[prop];
 
@@ -161,7 +167,7 @@ export async function retry<T> (
       context.attemptsRemaining--;
     }
 
-    if (options.timeout) {
+    if (options.timeout > 0) {
       return new Promise((resolve, reject) => {
         const timer = setTimeout(() => {
           if (options.handleTimeout) {
@@ -196,5 +202,30 @@ export async function retry<T> (
     await sleep(initialDelay);
   }
 
-  return makeAttempt();
+  if (options.totalTimeout > 0) {
+    return new Promise((resolve, reject) => {
+      const timer = setTimeout(() => {
+        context.abort();
+        if (options.handleTotalTimeout) {
+          resolve(options.handleTotalTimeout(options));
+        } else {
+          const err: any = new Error(`Total timeout (totalTimeout: ${options.totalTimeout})`);
+          err.code = 'TOTAL_TIMEOUT';
+          reject(err);
+        }
+      }, options.totalTimeout);
+
+      makeAttempt().then((result: T) => {
+        clearTimeout(timer);
+        resolve(result);
+      }).catch((err: any) => {
+        clearTimeout(timer);
+        reject(err);
+      });
+    });
+  } else {
+    // No totalTimeout provided so wait indefinitely for the returned promise
+    // to be resolved.
+    return makeAttempt();
+  }
 }

test/index.test.ts

@@ -19,9 +19,11 @@ test('should be able to calculate delays', (t) => {
     factor: 0,
     maxAttempts: 0,
     timeout: 0,
+    totalTimeout: 0,
     jitter: false,
     handleError: null,
     handleTimeout: null,
+    handleTotalTimeout: null,
     beforeAttempt: null,
     calculateDelay: null
   };
@@ -88,9 +90,11 @@ test('should default to 3 attempts with 200 delay', async (t) => {
       factor: 0,
       maxAttempts: 3,
       timeout: 0,
+      totalTimeout: 0,
       jitter: false,
       handleError: null,
       handleTimeout: null,
+      handleTotalTimeout: null,
       beforeAttempt: null,
       calculateDelay: null
     });
@@ -220,6 +224,74 @@ test('should support timeout for multiple attempts', async (t) => {
   t.is(err.code, 'ATTEMPT_TIMEOUT');
 });
 
+test('should support totalTimeout on first attempt', async (t) => {
+  const err = await t.throws(retry(async () => {
+    await sleep(500);
+  }, {
+    delay: 0,
+    totalTimeout: 50,
+    maxAttempts: 3
+  }));
+
+  t.is(err.code, 'TOTAL_TIMEOUT');
+});
+
+test('should support totalTimeout and handleTotalTimeout', async (t) => {
+  async function fallback () {
+    await sleep(100);
+    return 'used fallback';
+  }
+
+  const result = await retry<string>(async () => {
+    await sleep(500);
+    return 'did not use fallback';
+  }, {
+    delay: 0,
+    totalTimeout: 50,
+    maxAttempts: 2,
+    handleTotalTimeout: fallback
+  });
+
+  t.is(result, 'used fallback');
+});
+
+test('should allow handleTotalTimeout to throw an error', async (t) => {
+  const err = await t.throws(retry(async () => {
+    await sleep(500);
+  }, {
+    delay: 0,
+    totalTimeout: 50,
+    maxAttempts: 2,
+    handleTotalTimeout: async (context) => {
+      throw new Error('timeout occurred');
+    }
+  }));
+
+  t.is(err.message, 'timeout occurred');
+});
+
+test('should support totalTimeout that happens between attempts', async (t) => {
+  let attemptCount = 0;
+  const err = await t.throws(retry(async (context) => {
+    attemptCount++;
+
+    if (context.attemptNum > 2) {
+      return 'did not timeout';
+    } else {
+      await sleep(20);
+      throw new Error('fake error');
+    }
+  }, {
+    delay: 0,
+    totalTimeout: 50,
+    maxAttempts: 5
+  }));
+
+  // third attempt should timeout
+  t.is(attemptCount, 3);
+  t.is(err.code, 'TOTAL_TIMEOUT');
+});
+
 test('should support retries', async (t) => {
   const resultMessage = 'hello';
   const result = await retry(async (context) => {