Retry logic when rate-limited

docs/classes/google-spreadsheet.md

@@ -210,3 +210,13 @@ Param|Type|Required|Description
 `rangeId`|String|✅|ID of the range to remove
 
 
+### Retry logic
+
+### `setRetryOptions(metadataId)` (async) :id=fn-setRetryOptions
+> Set the retry options for when your requests are rate-limited (error 429)
+> If these options are not set then requests won't be retried
+
+Param|Type|Required|Description
+---|---|---|---
+`retries`|Number|✅|The number of times a request should be retried
+`retryDelay`|Number|✅|The time to delay in miliseconds between retry attempts

lib/GoogleSpreadsheet.js

@@ -57,6 +57,9 @@ class GoogleSpreadsheet {
       this._handleAxiosErrors.bind(this)
     );
 
+    this._retries = 0;
+    this._retryDelay = 3000;
+
     return this;
   }
 
@@ -122,6 +125,11 @@ class GoogleSpreadsheet {
     */
   }
 
+  setRetryOptions(retries, retryDelay) {
+    this._retries = retries;
+    this._retryDelay = retryDelay;
+  }
+
   // TODO: provide mechanism to share single JWT auth between docs?
 
   // INTERNAL UTILITY FUNCTIONS ////////////////////////////////////////////////////////////////////
@@ -150,7 +158,21 @@ class GoogleSpreadsheet {
 
   async _handleAxiosResponse(response) { return response; }
   async _handleAxiosErrors(error) {
-    // console.log(error);
+    if (_.get(error, 'response.status') === 429) {
+      const config = error.config;
+      const retryCount = config.retryCount || 0;
+
+      if (this._retries > 0 && retryCount < this._retries) {
+        config.retryCount = retryCount + 1;
+
+        return new Promise((resolve) => {
+          setTimeout(() => {
+            resolve(this.axios(config));
+          }, this._retryDelay);
+        });
+      }
+    }
+
     if (error.response && error.response.data) {
       // usually the error has a code and message, but occasionally not
       if (!error.response.data.error) throw error;