bpo-36287: Make ast.dump() not output optional fields and attributes with default values. (GH-18843)

The default values for optional fields and attributes of AST nodes are now set
as class attributes (e.g. Constant.kind is set to None).

1 files changed, 15 insertions, 14 deletions

diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
index e788485..c1e9f00 100644
--- a/Lib/test/test_ast.py
+++ b/Lib/test/test_ast.py
@@ -353,9 +353,11 @@ class AST_Tests(unittest.TestCase):
                                      'kw_defaults', 'kwarg', 'defaults'))
 
         with self.assertRaises(AttributeError):
-            x.vararg
+            x.args
+        self.assertIsNone(x.vararg)
 
         x = ast.arguments(*range(1, 8))
+        self.assertEqual(x.args, 2)
         self.assertEqual(x.vararg, 3)
 
     def test_field_attr_writable(self):
@@ -650,18 +652,18 @@ class ASTHelpers_Test(unittest.TestCase):
         node = ast.parse('spam(eggs, "and cheese")')
         self.assertEqual(ast.dump(node),
             "Module(body=[Expr(value=Call(func=Name(id='spam', ctx=Load()), "
-            "args=[Name(id='eggs', ctx=Load()), Constant(value='and cheese', kind=None)], "
+            "args=[Name(id='eggs', ctx=Load()), Constant(value='and cheese')], "
             "keywords=[]))], type_ignores=[])"
         )
         self.assertEqual(ast.dump(node, annotate_fields=False),
             "Module([Expr(Call(Name('spam', Load()), [Name('eggs', Load()), "
-            "Constant('and cheese', None)], []))], [])"
+            "Constant('and cheese')], []))], [])"
         )
         self.assertEqual(ast.dump(node, include_attributes=True),
             "Module(body=[Expr(value=Call(func=Name(id='spam', ctx=Load(), "
             "lineno=1, col_offset=0, end_lineno=1, end_col_offset=4), "
             "args=[Name(id='eggs', ctx=Load(), lineno=1, col_offset=5, "
-            "end_lineno=1, end_col_offset=9), Constant(value='and cheese', kind=None, "
+            "end_lineno=1, end_col_offset=9), Constant(value='and cheese', "
             "lineno=1, col_offset=11, end_lineno=1, end_col_offset=23)], keywords=[], "
             "lineno=1, col_offset=0, end_lineno=1, end_col_offset=24), "
             "lineno=1, col_offset=0, end_lineno=1, end_col_offset=24)], type_ignores=[])"
@@ -677,7 +679,7 @@ Module(
             func=Name(id='spam', ctx=Load()),
             args=[
                Name(id='eggs', ctx=Load()),
-               Constant(value='and cheese', kind=None)],
+               Constant(value='and cheese')],
             keywords=[]))],
    type_ignores=[])""")
         self.assertEqual(ast.dump(node, annotate_fields=False, indent='\t'), """\
@@ -688,7 +690,7 @@ Module(
 \t\t\t\tName('spam', Load()),
 \t\t\t\t[
 \t\t\t\t\tName('eggs', Load()),
-\t\t\t\t\tConstant('and cheese', None)],
+\t\t\t\t\tConstant('and cheese')],
 \t\t\t\t[]))],
 \t[])""")
         self.assertEqual(ast.dump(node, include_attributes=True, indent=3), """\
@@ -713,7 +715,6 @@ Module(
                   end_col_offset=9),
                Constant(
                   value='and cheese',
-                  kind=None,
                   lineno=1,
                   col_offset=11,
                   end_lineno=1,
@@ -762,7 +763,7 @@ Module(
         src = ast.parse('1 + 1', mode='eval')
         src.body.right = ast.copy_location(ast.Num(2), src.body.right)
         self.assertEqual(ast.dump(src, include_attributes=True),
-            'Expression(body=BinOp(left=Constant(value=1, kind=None, lineno=1, col_offset=0, '
+            'Expression(body=BinOp(left=Constant(value=1, lineno=1, col_offset=0, '
             'end_lineno=1, end_col_offset=1), op=Add(), right=Constant(value=2, '
             'lineno=1, col_offset=4, end_lineno=1, end_col_offset=5), lineno=1, '
             'col_offset=0, end_lineno=1, end_col_offset=5))'
@@ -777,7 +778,7 @@ Module(
         self.assertEqual(ast.dump(src, include_attributes=True),
             "Module(body=[Expr(value=Call(func=Name(id='write', ctx=Load(), "
             "lineno=1, col_offset=0, end_lineno=1, end_col_offset=5), "
-            "args=[Constant(value='spam', kind=None, lineno=1, col_offset=6, end_lineno=1, "
+            "args=[Constant(value='spam', lineno=1, col_offset=6, end_lineno=1, "
             "end_col_offset=12)], keywords=[], lineno=1, col_offset=0, end_lineno=1, "
             "end_col_offset=13), lineno=1, col_offset=0, end_lineno=1, "
             "end_col_offset=13), Expr(value=Call(func=Name(id='spam', ctx=Load(), "
@@ -792,8 +793,8 @@ Module(
         src = ast.parse('1 + 1', mode='eval')
         self.assertEqual(ast.increment_lineno(src, n=3), src)
         self.assertEqual(ast.dump(src, include_attributes=True),
-            'Expression(body=BinOp(left=Constant(value=1, kind=None, lineno=4, col_offset=0, '
-            'end_lineno=4, end_col_offset=1), op=Add(), right=Constant(value=1, kind=None, '
+            'Expression(body=BinOp(left=Constant(value=1, lineno=4, col_offset=0, '
+            'end_lineno=4, end_col_offset=1), op=Add(), right=Constant(value=1, '
             'lineno=4, col_offset=4, end_lineno=4, end_col_offset=5), lineno=4, '
             'col_offset=0, end_lineno=4, end_col_offset=5))'
         )
@@ -801,8 +802,8 @@ Module(
         src = ast.parse('1 + 1', mode='eval')
         self.assertEqual(ast.increment_lineno(src.body, n=3), src.body)
         self.assertEqual(ast.dump(src, include_attributes=True),
-            'Expression(body=BinOp(left=Constant(value=1, kind=None, lineno=4, col_offset=0, '
-            'end_lineno=4, end_col_offset=1), op=Add(), right=Constant(value=1, kind=None, '
+            'Expression(body=BinOp(left=Constant(value=1, lineno=4, col_offset=0, '
+            'end_lineno=4, end_col_offset=1), op=Add(), right=Constant(value=1, '
             'lineno=4, col_offset=4, end_lineno=4, end_col_offset=5), lineno=4, '
             'col_offset=0, end_lineno=4, end_col_offset=5))'
         )
@@ -821,7 +822,7 @@ Module(
         self.assertEqual(next(iterator).value, 23)
         self.assertEqual(next(iterator).value, 42)
         self.assertEqual(ast.dump(next(iterator)),
-            "keyword(arg='eggs', value=Constant(value='leek', kind=None))"
+            "keyword(arg='eggs', value=Constant(value='leek'))"
         )
 
     def test_get_docstring(self):