Add test for the make_checkers method

flake8/checker.py

@@ -349,7 +349,13 @@ class FileChecker(object):
         """Report an error by storing it in the results list."""
         if error_code is None:
             error_code, text = text.split(' ', 1)
-        physical_line = self.processor.line_for(line_number)
+
+        physical_line = ''
+        # If we're recovering from a problem in _make_processor, we will not
+        # have this attribute.
+        if getattr(self, 'processor', None):
+            physical_line = self.processor.line_for(line_number)
+
         error = (error_code, line_number, column, text, physical_line)
         self.results.append(error)
         return error_code

tests/unit/test_checker_manager.py

@@ -41,3 +41,20 @@ def test_multiprocessing_is_disabled():
     with mock.patch('flake8.checker.multiprocessing', None):
         manager = checker.Manager(style_guide, [], [])
         assert manager.jobs == 0
+
+
+def test_make_checkers():
+    """Verify that we create a list of FileChecker instances."""
+    style_guide = style_guide_mock()
+    files = ['file1', 'file2']
+    with mock.patch('flake8.checker.multiprocessing', None):
+        manager = checker.Manager(style_guide, files, [])
+
+    with mock.patch('flake8.utils.filenames_from') as filenames_from:
+        filenames_from.side_effect = [['file1'], ['file2']]
+        with mock.patch('flake8.utils.fnmatch', return_value=True):
+            with mock.patch('flake8.processor.FileProcessor'):
+                manager.make_checkers()
+
+    for file_checker in manager.checkers:
+        assert file_checker.filename in files