Extend F822 to support tuple concatenation (#544)

* Extend F822 to support tuple concatenation

* Add test case

* Use camel case

Author: Jackenmen

pyflakes/checker.py

@@ -542,7 +542,7 @@ class ExportBinding(Binding):
     can be determined statically, they will be treated as names for export and
     additional checking applied to them.
 
-    The only recognized C{__all__} assignment via list concatenation is in the
+    The only recognized C{__all__} assignment via list/tuple concatenation is in the
     following format:
 
         __all__ = ['a'] + ['b'] + ['c']
@@ -564,18 +564,18 @@ def _add_to_names(container):
 
         if isinstance(source.value, (ast.List, ast.Tuple)):
             _add_to_names(source.value)
-        # If concatenating lists
+        # If concatenating lists or tuples
         elif isinstance(source.value, ast.BinOp):
             currentValue = source.value
-            while isinstance(currentValue.right, ast.List):
+            while isinstance(currentValue.right, (ast.List, ast.Tuple)):
                 left = currentValue.left
                 right = currentValue.right
                 _add_to_names(right)
                 # If more lists are being added
                 if isinstance(left, ast.BinOp):
                     currentValue = left
                 # If just two lists are being added
-                elif isinstance(left, ast.List):
+                elif isinstance(left, (ast.List, ast.Tuple)):
                     _add_to_names(left)
                     # All lists accounted for - done
                     break

pyflakes/test/test_imports.py

@@ -1084,7 +1084,7 @@ def test_augmentedAssignment(self):
             __all__ += ['c', 'd']
         ''', m.UndefinedExport, m.UndefinedExport)
 
-    def test_concatenationAssignment(self):
+    def test_list_concatenation_assignment(self):
         """
         The C{__all__} variable is defined through list concatenation.
         """
@@ -1093,6 +1093,15 @@ def test_concatenationAssignment(self):
         __all__ = ['a'] + ['b'] + ['c']
         ''', m.UndefinedExport, m.UndefinedExport, m.UndefinedExport, m.UnusedImport)
 
+    def test_tuple_concatenation_assignment(self):
+        """
+        The C{__all__} variable is defined through tuple concatenation.
+        """
+        self.flakes('''
+        import sys
+        __all__ = ('a',) + ('b',) + ('c',)
+        ''', m.UndefinedExport, m.UndefinedExport, m.UndefinedExport, m.UnusedImport)
+
     def test_all_with_attributes(self):
         self.flakes('''
         from foo import bar