Fix some broken tests

Fixed broken tests due to bug in `temp_copy`.
The following tests are currently flaky:
- TestLibraryExamples.test_compile_all_libraries (fails _sometimes_ with
  exception 'window.selectedBoard is undefined')
- TestHome.test_login (passes _always_  when run on its own, fails _always_ when
  run with other tests)

Author: Brandon Duffany

codebender_testing/utils.py

@@ -4,6 +4,7 @@
 import json
 import os
 import re
+import shutil
 import tempfile
 
 from selenium.common.exceptions import NoSuchElementException
@@ -77,9 +78,8 @@ def temp_copy(fname):
     """
     extension = fname.split('.')[-1]
     with tempfile.NamedTemporaryFile(mode='w+b', suffix='.%s' % extension) as copy:
-        with open(fname, 'r') as original:
-            for line in original:
-                copy.write(line)
+        with open(fname, 'rb') as original:
+            shutil.copyfileobj(original, copy)
         copy.flush()
         yield copy
 

tests/compile_tester/test_compile_tester_projects.py

@@ -28,8 +28,10 @@ def test_compile_local_files(self, tester_login):
         """Tests that we can upload all of cb_compile_tester's projects
         (stored locally in test_data/cb_compile_tester), compile them,
         and finally delete them."""
+        upload_limit = None if self.run_full_compile_tests else 1
+
         test_files = [os.path.join(COMPILE_TESTER_DIR, name)
-            for name in next(os.walk(COMPILE_TESTER_DIR))[2]]
+            for name in next(os.walk(COMPILE_TESTER_DIR))[2]][:upload_limit]
         projects = [self.upload_project(fname) for fname in test_files]
         project_names, project_urls = zip(*projects)