Fix a crash when calling copy.copy() without args (#8784)

Author: jacobtylerwalls

doc/user_guide/installation/ide_integration/index.rst

@@ -40,7 +40,7 @@ Below you can find tutorials for some of the most common ones.
 .. _Sublime Text: https://packagecontrol.io/packages/SublimeLinter-pylint
 .. _Vim: https://www.vim.org/scripts/script.php?script_id=891
 .. _Visual Studio: https://docs.microsoft.com/visualstudio/python/code-pylint
-.. _Visual Studio Code: https://code.visualstudio.com/docs/python/linting#_pylint
+.. _Visual Studio Code: https://code.visualstudio.com/docs/python/linting
 .. _Visual Studio Code Pylint Extension: https://marketplace.visualstudio.com/items?itemName=ms-python.pylint
 .. _WingIDE: https://wingware.com/doc/warnings/external-checkers
 

doc/whatsnew/fragments/8774.bugfix

@@ -0,0 +1,3 @@
+Fixed a crash when calling ``copy.copy()`` without arguments.
+
+Closes #8774

pylint/checkers/stdlib.py

@@ -511,14 +511,23 @@ def _check_for_check_kw_in_run(self, node: nodes.Call) -> None:
             self.add_message("subprocess-run-check", node=node, confidence=INFERENCE)
 
     def _check_shallow_copy_environ(self, node: nodes.Call) -> None:
-        arg = utils.get_argument_from_call(node, position=0)
+        confidence = HIGH
+        try:
+            arg = utils.get_argument_from_call(node, position=0, keyword="x")
+        except utils.NoSuchArgumentError:
+            arg = utils.infer_kwarg_from_call(node, keyword="x")
+            if not arg:
+                return
+            confidence = INFERENCE
         try:
             inferred_args = arg.inferred()
         except astroid.InferenceError:
             return
         for inferred in inferred_args:
             if inferred.qname() == OS_ENVIRON:
-                self.add_message("shallow-copy-environ", node=node)
+                self.add_message(
+                    "shallow-copy-environ", node=node, confidence=confidence
+                )
                 break
 
     @utils.only_required_for_messages(

tests/functional/s/shallow_copy_environ.py

@@ -27,3 +27,11 @@
 import os
 
 copy.deepcopy(os.environ)
+
+# Edge cases
+copy.copy()  # [no-value-for-parameter]
+copy.copy(x=test_dict)
+copy.copy(x=os.environ)  # [shallow-copy-environ]
+copy.copy(**{"x": os.environ})  # [shallow-copy-environ]
+copy.copy(**{"y": os.environ})  # [unexpected-keyword-arg]
+copy.copy(y=os.environ)  # [no-value-for-parameter, unexpected-keyword-arg]

tests/functional/s/shallow_copy_environ.txt

@@ -1,2 +1,8 @@
-shallow-copy-environ:7:0:7:21::Using copy.copy(os.environ). Use os.environ.copy() instead.:UNDEFINED
-shallow-copy-environ:17:0:17:18::Using copy.copy(os.environ). Use os.environ.copy() instead.:UNDEFINED
+shallow-copy-environ:7:0:7:21::Using copy.copy(os.environ). Use os.environ.copy() instead.:HIGH
+shallow-copy-environ:17:0:17:18::Using copy.copy(os.environ). Use os.environ.copy() instead.:HIGH
+no-value-for-parameter:32:0:32:11::No value for argument 'x' in function call:UNDEFINED
+shallow-copy-environ:34:0:34:23::Using copy.copy(os.environ). Use os.environ.copy() instead.:HIGH
+shallow-copy-environ:35:0:35:30::Using copy.copy(os.environ). Use os.environ.copy() instead.:INFERENCE
+unexpected-keyword-arg:36:0:36:30::Unexpected keyword argument 'y' in function call:UNDEFINED
+no-value-for-parameter:37:0:37:23::No value for argument 'x' in function call:UNDEFINED
+unexpected-keyword-arg:37:0:37:23::Unexpected keyword argument 'y' in function call:UNDEFINED