New naming convention for fixers

my2to3/fixes/__init__.py

+import lib2to3.fixer_base
+import os
+
+
+class BaseFix(lib2to3.fixer_base.BaseFix):
+  def start_tree(self, tree, filename):
+    sep = '-' * 5 # Arbitrary
+    if sep in filename:
+      filename = filename.split(sep, 1)[1].replace(sep, os.sep)
+
+    super(BaseFix, self).start_tree(tree, filename)

my2to3/fixes/fix_division.py → my2to3/fixes/fix_division_support.py

@@ -6,7 +6,8 @@ from lib2to3.pytree import Leaf, Node
 import os
 import re
 
-from my2to3.util import add_future, BaseFix
+from my2to3.util import add_future
+from my2to3.fixes import BaseFix
 
 trace_file_match = re.compile(r"^(.*)\|(.*)\|(.*) <type '(.*)'> / <type '(.*)'>$").match
 
@@ -46,7 +47,7 @@ def analyze_data(data):
   return False
 
 
-class FixDivision(BaseFix):
+class FixDivisionSupport(BaseFix):
   """Rewrites division_traced(n, a, b) into Py2/Py3-compatible division
 
   The `TRACE_FILE` environment variable must point to the trace data file. See
@@ -62,7 +63,7 @@ class FixDivision(BaseFix):
             """
 
   def start_tree(self, tree, filename):
-    super(FixDivision, self).start_tree(tree, filename)
+    super(FixDivisionSupport, self).start_tree(tree, filename)
 
     self.absolute_filename = os.path.abspath(filename)
 

my2to3/fixes/fix_trace_division.py → my2to3/fixes/fix_division_trace.py

@@ -6,10 +6,10 @@ from lib2to3.pygram import python_symbols as syms
 from lib2to3.pytree import Node
 import sys
 
-from my2to3.util import BaseFix
+from my2to3.fixes import BaseFix
 
 
-class FixTraceDivision(BaseFix):
+class FixDivisionTrace(BaseFix):
   """Rewrites a/b into division_traced(a, b)
 
   division_traced can be a function that looks up the stack and record the operand types, for example:
@@ -30,7 +30,7 @@ class FixTraceDivision(BaseFix):
       __builtin__.division_traced = division_traced
   """
   def start_tree(self, tree, filename):
-    super(FixTraceDivision, self).start_tree(tree, filename)
+    super(FixDivisionTrace, self).start_tree(tree, filename)
     self.ids = defaultdict(int)
 
   def match(self, node):

my2to3/tests/testFixTraceDivision.py → my2to3/tests/testFixDivisionTrace.py

@@ -9,7 +9,7 @@ class FixerTestCase(lib2to3FixerTestCase):
 
 
 class testFixTraceDivision(FixerTestCase):
-  fixer = "trace_division"
+  fixer = "division_trace"
 
   def test_simple_division(self):
     b = """x / y"""

my2to3/util.py

 from lib2to3 import fixer_util
-import lib2to3.fixer_base
 from lib2to3.pytree import Leaf, Node
 from lib2to3.pgen2 import token
 from lib2to3.pygram import python_symbols as syms
-import os
-
-
-class BaseFix(lib2to3.fixer_base.BaseFix):
-  def start_tree(self, tree, filename):
-    sep = '-' * 5 # Arbitrary
-    if sep in filename:
-      filename = filename.split(sep, 1)[1].replace(sep, os.sep)
-
-    super(BaseFix, self).start_tree(tree, filename)
 
 
 # https://github.com/python-modernize/python-modernize/blob/84d973cb7b8153f9f7f22c3574a59312b2372ccb/libmodernize/__init__.py#L10-49
@@ -58,7 +47,6 @@ def check_future_import(node):
         assert 0, "strange import"
 
 
-
 # https://github.com/python-modernize/python-modernize/blob/84d973cb7b8153f9f7f22c3574a59312b2372ccb/libmodernize/__init__.py#L51-L66
 def add_future(node, symbol):