Network: Retry requests that failed in flight

src/libs/Network.js

@@ -225,7 +225,16 @@ function processNetworkRequestQueue() {
         onRequest(queuedRequest, finalParameters);
         HttpUtils.xhr(queuedRequest.command, finalParameters, queuedRequest.type, queuedRequest.shouldUseSecure)
             .then(response => onResponse(queuedRequest, response))
-            .catch(error => onError(queuedRequest, error));
+            .catch((error) => {
+                // When the request did not reach its destination add it back the queue to be retried
+                const shouldRetry = lodashGet(queuedRequest, 'data.shouldRetry');
+                if (shouldRetry) {
+                    networkRequestQueue.push(queuedRequest);
+                    return;
+                }
+
+                onError(queuedRequest, error);
+            });
     });
 
     // We should clear the NETWORK_REQUEST_QUEUE when we have loaded the persisted requests & they are processed.

tests/unit/NetworkTest.js

@@ -271,3 +271,35 @@ test('retry network request if auth and credentials are not read from Onyx yet',
         expect(spyHttpUtilsXhr).toHaveBeenCalled();
     });
 });
+
+test('retry network request if connection is lost while request is running', () => {
+    // Given a xhr mock that will fail as if network connection dropped
+    const xhr = jest.spyOn(HttpUtils, 'xhr')
+        .mockImplementationOnce(() => {
+            Onyx.merge(ONYXKEYS.NETWORK, {isOffline: true});
+            return Promise.reject(new Error('Network request failed'));
+        })
+        .mockResolvedValue({jsonCode: 200, fromRetriedResult: true});
+
+    // Given a regular "retriable" request (that is bound to fail)
+    const promise = Network.post('Get');
+
+    return waitForPromisesToResolve()
+        .then(() => {
+            // When network connection is recovered
+            Onyx.merge(ONYXKEYS.NETWORK, {isOffline: false});
+            return waitForPromisesToResolve();
+        })
+        .then(() => {
+            // Advance the network request queue by 1 second so that it can realize it's back online
+            jest.advanceTimersByTime(1000);
+            return waitForPromisesToResolve();
+        })
+        .then(() => {
+            // Then the request should be attempted again
+            expect(xhr).toHaveBeenCalledTimes(2);
+
+            // And the promise should be resolved with the 2nd call that succeeded
+            return expect(promise).resolves.toEqual({jsonCode: 200, fromRetriedResult: true});
+        });
+});