Merge pull request #1261 from bojand/master

add filter option to retry() and retryable(). PR for #1256.

1 files changed, 21 insertions, 2 deletions

diff --git a/lib/retry.js b/lib/retry.js
index 8163ad9..a5ad866 100644
--- a/lib/retry.js
+++ b/lib/retry.js
@@ -19,6 +19,11 @@ import constant from 'lodash/constant';
  * * `interval` - The time to wait between retries, in milliseconds.  The
  *   default is `0`. The interval may also be specified as a function of the
  *   retry count (see example).
+ * * `errorFilter` - An optional synchronous function that is invoked on
+ *   erroneous result. If it returns `true` the retry attempts will continue;
+ *   if the function returns `false` the retry flow is aborted with the current
+ *   attempt's error and result being returned to the final callback.
+ *   Invoked with (err).
  * * If `opts` is a number, the number specifies the number of times to retry,
  *   with the default interval of `0`.
  * @param {Function} task - A function which receives two arguments: (1) a
@@ -62,6 +67,16 @@ import constant from 'lodash/constant';
  *     // do something with the result
  * });
  *
+ * // try calling apiMethod only when error condition satisfies, all other
+ * // errors will abort the retry control flow and return to final callback
+ * async.retry({
+ *   errorFilter: function(err) {
+ *     return err.message === 'Temporary error'; // only retry on a specific error
+ *   }
+ * }, apiMethod, function(err, result) {
+ *     // do something with the result
+ * });
+ *
  * // It can also be embedded within other control flow functions to retry
  * // individual methods that are not as reliable, like this:
  * async.auto({
@@ -70,6 +85,7 @@ import constant from 'lodash/constant';
  * }, function(err, results) {
  *     // do something with the results
  * });
+ *
  */
 export default function retry(opts, task, callback) {
     var DEFAULT_TIMES = 5;
@@ -87,6 +103,8 @@ export default function retry(opts, task, callback) {
             acc.intervalFunc = typeof t.interval === 'function' ?
                 t.interval :
                 constant(+t.interval || DEFAULT_INTERVAL);
+
+            acc.errorFilter = t.errorFilter;
         } else if (typeof t === 'number' || typeof t === 'string') {
             acc.times = +t || DEFAULT_TIMES;
         } else {
@@ -94,7 +112,6 @@ export default function retry(opts, task, callback) {
         }
     }
 
-
     if (arguments.length < 3 && typeof opts === 'function') {
         callback = task || noop;
         task = opts;
@@ -110,7 +127,9 @@ export default function retry(opts, task, callback) {
     var attempt = 1;
     function retryAttempt() {
         task(function(err) {
-            if (err && attempt++ < options.times) {
+            if (err && attempt++ < options.times &&
+                (typeof options.errorFilter != 'function' ||
+                    options.errorFilter(err))) {
                 setTimeout(retryAttempt, options.intervalFunc(attempt));
             } else {
                 callback.apply(null, arguments);