add selenium test for upload modal not losing content on close

This selenium makes sure that when users reopen upload modal, the content from prior or inprogress uploads is still there

lib/galaxy_test/selenium/test_uploads.py

@@ -174,6 +174,36 @@ def test_upload_paired_list(self):
         self.history_panel_wait_for_hid_hidden(3)
         self.history_panel_wait_for_hid_hidden(4)
 
+    @selenium_test
+    def test_upload_modal_retains_content(self):
+        self.home()
+
+        # initialize 2 uploads and close modal
+        self.upload_start_click()
+        self.upload_queue_local_file(self.get_filename("1.sam"))
+        self.upload_paste_data("some pasted data")
+        self.wait_for_and_click_selector("button#btn-close")
+
+        # reopen modal and check that the files are still there
+        self.upload_start_click()
+        self.wait_for_selector_visible("#upload-row-0.upload-init")
+        self.wait_for_selector_visible("#upload-row-1.upload-init")
+
+        # perform upload and close modal
+        self.upload_start()
+        self.wait_for_and_click_selector("button#btn-close")
+
+        # add another pasted file, but don't upload it
+        self.upload_start_click()
+        self.upload_paste_data("some more pasted data")
+        self.wait_for_and_click_selector("button#btn-close")
+
+        # reopen modal and see 2 uploaded, 1 yet to upload
+        self.upload_start_click()
+        self.wait_for_selector_visible("#upload-row-0.upload-success")
+        self.wait_for_selector_visible("#upload-row-1.upload-success")
+        self.wait_for_selector_visible("#upload-row-2.upload-init")
+
     @selenium_test
     @pytest.mark.gtn_screenshot
     @pytest.mark.local