feat(http-client): Retry requests that failed with closed connection

Requests that fail with closed connection errors (ECONNRESET, EPIPE) are
automatically retried.

- `ECONNRESET` (Connection reset by peer): A connection was forcibly
  closed by a peer.closed by a peer. This normally results from a loss
  of the connection on the remote socket due to a timeout or reboot.
  Commonly encountered via the http and net modules.

- `EPIPE` (Broken pipe): A write on a pipe, socket, or FIFO for which
  there is no process to read the data. Commonly encountered at the net
  and http layers, indicative that the remote side of the stream being
  written to has been closed.

Fixes: stripe#1040

lib/StripeResource.js

@@ -273,7 +273,15 @@ StripeResource.prototype = {
   },
 
   // For more on when and how to retry API requests, see https://stripe.com/docs/error-handling#safely-retrying-requests-with-idempotency
-  _shouldRetry(res, numRetries, maxRetries) {
+  _shouldRetry(res, numRetries, maxRetries, error) {
+    if (
+      error &&
+      numRetries === 0 &&
+      HttpClient.CONNECTION_CLOSED_ERROR_CODES.includes(error.code)
+    ) {
+      return true;
+    }
+
     // Do not retry if we are out of retries.
     if (numRetries >= maxRetries) {
       return false;
@@ -502,7 +510,7 @@ StripeResource.prototype = {
           }
         })
         .catch((error) => {
-          if (this._shouldRetry(null, requestRetries, maxRetries)) {
+          if (this._shouldRetry(null, requestRetries, maxRetries, error)) {
             return retryRequest(
               makeRequest,
               apiVersion,

lib/net/HttpClient.js

@@ -31,6 +31,7 @@ class HttpClient {
   }
 }
 
+HttpClient.CONNECTION_CLOSED_ERROR_CODES = ['ECONNRESET', 'EPIPE'];
 HttpClient.TIMEOUT_ERROR_CODE = 'ETIMEDOUT';
 
 class HttpClientResponse {

test/StripeResource.spec.js

@@ -356,6 +356,39 @@ describe('StripeResource', () => {
         );
       });
 
+      it('retries closed connection errors once', (done) => {
+        nock(`https://${options.host}`)
+          .post(options.path, options.params)
+          .replyWithError({
+            code: 'ECONNRESET',
+            errno: 'ECONNRESET',
+          })
+          .post(options.path, options.params)
+          .reply(200, {
+            id: 'ch_123',
+            object: 'charge',
+            amount: 1000,
+          });
+
+        realStripe.charges.create(options.data, (err, charge) => {
+          expect(charge.id).to.equal('ch_123');
+          done(err);
+        });
+      });
+
+      it('throws on multiple closed connection errors', (done) => {
+        nock(`https://${options.host}`)
+          .post(options.path, options.params)
+          .replyWithError({ code: 'ECONNRESET' })
+          .post(options.path, options.params)
+          .replyWithError({ code: 'ECONNRESET' });
+
+        realStripe.charges.create(options.data, (err) => {
+          expect(err.detail.code).to.deep.equal('ECONNRESET');
+          done();
+        });
+      });
+
       it('should retry the request if max retries are set', (done) => {
         nock(`https://${options.host}`)
           .post(options.path, options.params)