Add the "ast" module, containing helpers to ease use of the "_ast" classes.

1 files changed, 100 insertions, 9 deletions

diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
index 9d2bd66..00a5aae 100644
--- a/Lib/test/test_ast.py
+++ b/Lib/test/test_ast.py
@@ -1,6 +1,6 @@
 import sys, itertools, unittest
 from test import test_support
-import _ast
+import ast
 
 def to_tuple(t):
     if t is None or isinstance(t, (basestring, int, long, complex)):
@@ -123,9 +123,9 @@ eval_tests = [
 class AST_Tests(unittest.TestCase):
 
     def _assert_order(self, ast_node, parent_pos):
-        if not isinstance(ast_node, _ast.AST) or ast_node._fields is None:
+        if not isinstance(ast_node, ast.AST) or ast_node._fields is None:
             return
-        if isinstance(ast_node, (_ast.expr, _ast.stmt, _ast.excepthandler)):
+        if isinstance(ast_node, (ast.expr, ast.stmt, ast.excepthandler)):
             node_pos = (ast_node.lineno, ast_node.col_offset)
             self.assert_(node_pos >= parent_pos)
             parent_pos = (ast_node.lineno, ast_node.col_offset)
@@ -142,29 +142,29 @@ class AST_Tests(unittest.TestCase):
                                     (single_tests, single_results, "single"),
                                     (eval_tests, eval_results, "eval")):
             for i, o in itertools.izip(input, output):
-                ast_tree = compile(i, "?", kind, _ast.PyCF_ONLY_AST)
+                ast_tree = compile(i, "?", kind, ast.PyCF_ONLY_AST)
                 self.assertEquals(to_tuple(ast_tree), o)
                 self._assert_order(ast_tree, (0, 0))
 
     def test_nodeclasses(self):
-        x = _ast.BinOp(1, 2, 3, lineno=0)
+        x = ast.BinOp(1, 2, 3, lineno=0)
         self.assertEquals(x.left, 1)
         self.assertEquals(x.op, 2)
         self.assertEquals(x.right, 3)
         self.assertEquals(x.lineno, 0)
 
         # node raises exception when not given enough arguments
-        self.assertRaises(TypeError, _ast.BinOp, 1, 2)
+        self.assertRaises(TypeError, ast.BinOp, 1, 2)
 
         # can set attributes through kwargs too
-        x = _ast.BinOp(left=1, op=2, right=3, lineno=0)
+        x = ast.BinOp(left=1, op=2, right=3, lineno=0)
         self.assertEquals(x.left, 1)
         self.assertEquals(x.op, 2)
         self.assertEquals(x.right, 3)
         self.assertEquals(x.lineno, 0)
 
         # this used to fail because Sub._fields was None
-        x = _ast.Sub()
+        x = ast.Sub()
 
     def test_pickling(self):
         import pickle
@@ -181,8 +181,99 @@ class AST_Tests(unittest.TestCase):
                     ast2 = mod.loads(mod.dumps(ast, protocol))
                     self.assertEquals(to_tuple(ast2), to_tuple(ast))
 
+
+class ASTHelpers_Test(unittest.TestCase):
+
+    def test_parse(self):
+        a = ast.parse('foo(1 + 1)')
+        b = compile('foo(1 + 1)', '<unknown>', 'exec', ast.PyCF_ONLY_AST)
+        self.assertEqual(ast.dump(a), ast.dump(b))
+
+    def test_dump(self):
+        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()), Str(s='and cheese')], "
+            "keywords=[], starargs=None, kwargs=None))])"
+        )
+        self.assertEqual(ast.dump(node, annotate_fields=False),
+            "Module([Expr(Call(Name('spam', Load()), [Name('eggs', Load()), "
+            "Str('and cheese')], [], None, None))])"
+        )
+        self.assertEqual(ast.dump(node, include_attributes=True),
+            "Module(body=[Expr(value=Call(func=Name(id='spam', ctx=Load(), "
+            "lineno=1, col_offset=0), args=[Name(id='eggs', ctx=Load(), "
+            "lineno=1, col_offset=5), Str(s='and cheese', lineno=1, "
+            "col_offset=11)], keywords=[], starargs=None, kwargs=None, "
+            "lineno=1, col_offset=0), lineno=1, col_offset=0)])"
+        )
+
+    def test_copy_location(self):
+        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=Num(n=1, lineno=1, col_offset=0), '
+            'op=Add(), right=Num(n=2, lineno=1, col_offset=4), lineno=1, '
+            'col_offset=0))'
+        )
+
+    def test_fix_missing_locations(self):
+        src = ast.parse('write("spam")')
+        src.body.append(ast.Expr(ast.Call(ast.Name('spam', ast.Load()),
+                                          [ast.Str('eggs')], [], None, None)))
+        self.assertEqual(src, ast.fix_missing_locations(src))
+        self.assertEqual(ast.dump(src, include_attributes=True),
+            "Module(body=[Expr(value=Call(func=Name(id='write', ctx=Load(), "
+            "lineno=1, col_offset=0), args=[Str(s='spam', lineno=1, "
+            "col_offset=6)], keywords=[], starargs=None, kwargs=None, "
+            "lineno=1, col_offset=0), lineno=1, col_offset=0), "
+            "Expr(value=Call(func=Name(id='spam', ctx=Load(), lineno=1, "
+            "col_offset=0), args=[Str(s='eggs', lineno=1, col_offset=0)], "
+            "keywords=[], starargs=None, kwargs=None, lineno=1, "
+            "col_offset=0), lineno=1, col_offset=0)])"
+        )
+
+    def test_increment_lineno(self):
+        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=Num(n=1, lineno=4, col_offset=0), '
+            'op=Add(), right=Num(n=1, lineno=4, col_offset=4), lineno=4, '
+            'col_offset=0))'
+        )
+
+    def test_iter_fields(self):
+        node = ast.parse('foo()', mode='eval')
+        d = dict(ast.iter_fields(node.body))
+        self.assertEqual(d.pop('func').id, 'foo')
+        self.assertEqual(d, {'keywords': [], 'kwargs': None,
+                             'args': [], 'starargs': None})
+
+    def test_iter_child_nodes(self):
+        node = ast.parse("spam(23, 42, eggs='leek')", mode='eval')
+        self.assertEqual(len(list(ast.iter_child_nodes(node.body))), 4)
+        iterator = ast.iter_child_nodes(node.body)
+        self.assertEqual(next(iterator).id, 'spam')
+        self.assertEqual(next(iterator).n, 23)
+        self.assertEqual(next(iterator).n, 42)
+        self.assertEqual(ast.dump(next(iterator)),
+            "keyword(arg='eggs', value=Str(s='leek'))"
+        )
+
+    def test_get_docstring(self):
+        node = ast.parse('def foo():\n  """line one\n  line two"""')
+        self.assertEqual(ast.get_docstring(node.body[0]),
+                         'line one\nline two')
+
+    def test_literal_eval(self):
+        self.assertEqual(ast.literal_eval('[1, 2, 3]'), [1, 2, 3])
+        self.assertEqual(ast.literal_eval('{"foo": 42}'), {"foo": 42})
+        self.assertEqual(ast.literal_eval('(True, False, None)'), (True, False, None))
+        self.assertRaises(ValueError, ast.literal_eval, 'foo()')
+
+
 def test_main():
-    test_support.run_unittest(AST_Tests)
+    test_support.run_unittest(AST_Tests, ASTHelpers_Test)
 
 def main():
     if __name__ != '__main__':