Resolve "Updating own past feedback sets other tutors assignment to is_done=True"

Closes #155 (closed)

functional_tests/test_export_modal.py

 import json
 import os
+from pathlib import Path
 
 from django.test import LiveServerTestCase
 from selenium import webdriver
@@ -10,18 +11,22 @@ from functional_tests.util import login, create_browser, reset_browser_after_tes
 from util import factory_boys as fact
 
 
-def expect_file_to_be_present(path):
+def expect_file_to_be_downloaded(path):
+    """
+    Checks if a file has finished downloading by checking if a file exists at the path and
+    no accompanying `<path>.part` file.
+    :param path: path to check
+    :return:
+    """
     def condition(*args):
-        try:
-            with open(path):
-                pass
-        except FileNotFoundError:
-            return False
-        return True
+        file_present = Path(path).is_file()
+        partial_file_present = Path(os.path.join(path, '.part')).is_file()
+        return file_present and not partial_file_present
     return condition
 
 
 JSON_EXPORT_FILE = os.path.join(os.path.dirname(__file__), 'export.json')
+SCREENSHOTS = os.path.join(os.path.dirname(__file__), 'screenshots')
 
 
 class ExportTestModal(LiveServerTestCase):
@@ -51,6 +56,15 @@ class ExportTestModal(LiveServerTestCase):
         )
 
     def tearDown(self):
+        try:
+            os.mkdir(SCREENSHOTS)
+        except FileExistsError:
+            pass
+        for method, error in self._outcome.errors:
+            if error:
+                self.browser.get_screenshot_as_file(
+                    os.path.join(SCREENSHOTS, self.id() + ".png")
+                )
         reset_browser_after_test(self.browser, self.live_server_url)
 
     def _login(self):
@@ -97,8 +111,8 @@ class ExportTestModal(LiveServerTestCase):
                          list_elements[1].find_element_by_tag_name('a').text)
 
     def test_export_student_scores_as_json(self):
-        self._login()
         fact.StudentInfoFactory()
+        self._login()
         export_btn = self.browser.find_element_by_id('export-btn')
         export_btn.click()
         export_scores = self.browser.find_element_by_id('export-list0')
@@ -110,21 +124,29 @@ class ExportTestModal(LiveServerTestCase):
         export_type_json.click()
         data_export_btn = data_export_modal.find_element_by_id('export-data-download-btn')
         data_export_btn.click()
-        WebDriverWait(self.browser, 10).until(expect_file_to_be_present(JSON_EXPORT_FILE))
-        with open(JSON_EXPORT_FILE) as f:
-            data = json.load(f)
-        self.assertEqual('B.Inf.4242 Test Module', data[0]['Exam'])
-        os.remove(JSON_EXPORT_FILE)
+        WebDriverWait(self.browser, 10).until(expect_file_to_be_downloaded(JSON_EXPORT_FILE))
+        try:
+            with open(JSON_EXPORT_FILE) as f:
+                data = json.load(f)
+            self.assertEqual('B.Inf.4242 Test Module', data[0]['Exam'])
+        except Exception as e:
+            raise e
+        finally:
+            os.remove(JSON_EXPORT_FILE)
 
     def test_export_instance(self):
-        self._login()
         fact.SubmissionFactory()
+        self._login()
         self.browser.find_element_by_id('export-btn').click()
         self.browser.find_element_by_id('export-list1').click()
         instance_export_modal = self.browser.find_element_by_id('instance-export-modal')
         instance_export_modal.find_element_by_id('instance-export-dl').click()
-        WebDriverWait(self.browser, 10).until(expect_file_to_be_present(JSON_EXPORT_FILE))
-        with open(JSON_EXPORT_FILE) as f:
-            data = json.load(f)
-        self.assertEqual('B.Inf.4242 Test Module', data['examTypes'][0]['moduleReference'])
-        os.remove(JSON_EXPORT_FILE)
+        WebDriverWait(self.browser, 10).until(expect_file_to_be_downloaded(JSON_EXPORT_FILE))
+        try:
+            with open(JSON_EXPORT_FILE) as f:
+                data = json.load(f)
+            self.assertEqual('B.Inf.4242 Test Module', data['examTypes'][0]['moduleReference'])
+        except Exception as e:
+            raise e
+        finally:
+            os.remove(JSON_EXPORT_FILE)