fix: Check for uploader to prevent errors when calling upload() too early (#938)

Author: mmustafa-tse

src/mp-instance.js

@@ -591,7 +591,7 @@ export default function mParticleInstance(instanceName) {
                     Constants.NativeSdkPaths.Upload
                 );
             } else {
-                self._APIClient.uploader.prepareAndUpload(false, false);
+                self._APIClient?.uploader?.prepareAndUpload(false, false);
             }
         }
     };

test/src/tests-batchUploader.ts

@@ -329,6 +329,20 @@ describe('batch uploader', () => {
                 })
             });
 
+            it('should not throw an error when upload is called while storage has not been created yet', async () => {
+                window.localStorage.clear();
+                window.sessionStorage.clear();
+
+                window.mParticle.init(apiKey, window.mParticle.config);
+
+                const mpInstance = window.mParticle.getInstance();
+                const uploader = mpInstance._APIClient.uploader;
+
+                expect(uploader).to.equal(null)
+
+                expect(() => { window.mParticle.upload() }).to.not.throw(TypeError, /Cannot read properties of null \(reading 'prepareAndUpload'\)/)
+            });
+
             it('should return batches that fail to unknown HTTP errors', async () => {
                 window.mParticle.init(apiKey, window.mParticle.config);