Add a function to identify ast Constant nodes more granularly

rope/base/ast.py

@@ -1,8 +1,24 @@
 import ast
+import sys
 from ast import *  # noqa: F401,F403
 
 from rope.base import fscommands
 
+try:
+    from ast import _const_node_type_names
+except ImportError:
+    # backported from stdlib `ast`
+    _const_node_type_names = {
+        bool: "NameConstant",  # should be before int
+        type(None): "NameConstant",
+        int: "Num",
+        float: "Num",
+        complex: "Num",
+        str: "Str",
+        bytes: "Bytes",
+        type(...): "Ellipsis",
+    }
+
 
 def parse(source, filename="<string>", *args, **kwargs):  # type: ignore
     if isinstance(source, str):
@@ -35,3 +51,20 @@ def visit(self, node):
         method = "_" + node.__class__.__name__
         visitor = getattr(self, method, self.generic_visit)
         return visitor(node)
+
+
+def get_const_subtype_name(node):
+    """Get pre-3.8 ast node name"""
+    # fmt: off
+    assert sys.version_info >= (3, 8), "This should only be called in Python 3.8 and above"
+    # fmt: on
+    assert isinstance(node, ast.Constant)
+    return _const_node_type_names[type(node.value)]
+
+
+def get_node_type_name(node):
+    return (
+        get_const_subtype_name(node)
+        if isinstance(node, ast.Constant)
+        else node.__class__.__name__
+    )

ropetest/refactor/patchedasttest.py

@@ -8,7 +8,6 @@
 from ropetest import testutils
 
 NameConstant = "Name" if sys.version_info <= (3, 8) else "NameConstant"
-Bytes = "Bytes" if (3, 0) <= sys.version_info <= (3, 8) else "Str"
 
 
 class PatchedASTTest(unittest.TestCase):
@@ -57,8 +56,8 @@ def test_bytes_string(self):
         checker = _ResultChecker(self, ast_frag)
         str_fragment = 'b"("'
         start = source.index(str_fragment)
-        checker.check_region(Bytes, start, start + len(str_fragment))
-        checker.check_children(Bytes, [str_fragment])
+        checker.check_region("Bytes", start, start + len(str_fragment))
+        checker.check_children("Bytes", [str_fragment])
 
     def test_integer_literals_and_region(self):
         source = "a = 10\n"
@@ -839,28 +838,14 @@ def test_list_comp_node_with_multiple_comprehensions(self):
         )
 
     def test_set_node(self):
-        # make sure we are in a python version with set literals
         source = "{1, 2}\n"
-
-        try:
-            eval(source)
-        except SyntaxError:
-            return
-
         ast_frag = patchedast.get_patched_ast(source, True)
         checker = _ResultChecker(self, ast_frag)
         checker.check_region("Set", 0, len(source) - 1)
         checker.check_children("Set", ["{", "", "Num", "", ",", " ", "Num", "", "}"])
 
     def test_set_comp_node(self):
-        # make sure we are in a python version with set comprehensions
         source = "{i for i in range(1) if True}\n"
-
-        try:
-            eval(source)
-        except SyntaxError:
-            return
-
         ast_frag = patchedast.get_patched_ast(source, True)
         checker = _ResultChecker(self, ast_frag)
         checker.check_region("SetComp", 0, len(source) - 1)
@@ -873,14 +858,7 @@ def test_set_comp_node(self):
         )
 
     def test_dict_comp_node(self):
-        # make sure we are in a python version with dict comprehensions
         source = "{i:i for i in range(1) if True}\n"
-
-        try:
-            eval(source)
-        except SyntaxError:
-            return
-
         ast_frag = patchedast.get_patched_ast(source, True)
         checker = _ResultChecker(self, ast_frag)
         checker.check_region("DictComp", 0, len(source) - 1)
@@ -1285,7 +1263,7 @@ def test_match_node_with_constant_match_value(self):
         checker = _ResultChecker(self, ast_frag)
         self.assert_single_case_match_block(checker, "MatchValue")
         checker.check_children("MatchValue", [
-            "Constant"
+            "Num"
         ])
 
     @testutils.only_for_versions_higher("3.10")
@@ -1340,7 +1318,7 @@ def test_match_node_with_match_class(self):
             ")",
         ])
         checker.check_children("MatchValue", [
-            "Constant"
+            "Num"
         ])
 
     @testutils.only_for_versions_higher("3.10")
@@ -1488,7 +1466,7 @@ def test_match_node_with_match_mapping_match_as(self):
         checker.check_children("MatchMapping", [
             "{",
             "",
-            "Constant",
+            "Str",
             "",
             ":",
             " ",
@@ -1519,17 +1497,10 @@ class Search:
 
             def __call__(self, node):
                 for text in goal:
-                    if sys.version_info >= (3, 8) and text in [
-                        "Num",
-                        "Str",
-                        "NameConstant",
-                        "Ellipsis",
-                    ]:
-                        text = "Constant"
                     if str(node).startswith(text):
                         self.result = node
                         break
-                    if node.__class__.__name__.startswith(text):
+                    if ast.get_node_type_name(node).startswith(text):
                         self.result = node
                         break
                 return self.result is not None
@@ -1554,15 +1525,8 @@ def check_children(self, text, children):
                     break
             else:
                 self.test_case.assertNotEqual("", text, "probably ignoring some node")
-                if sys.version_info >= (3, 8) and expected in [
-                    "Num",
-                    "Str",
-                    "NameConstant",
-                    "Ellipsis",
-                ]:
-                    expected = "Constant"
                 self.test_case.assertTrue(
-                    child.__class__.__name__.startswith(expected),
+                    ast.get_node_type_name(child).startswith(expected),
                     msg="Expected <%s> but was <%s>"
-                    % (expected, child.__class__.__name__),
+                    % (expected, ast.get_node_type_name(child)),
                 )