Apply infer_kwarg_from_call() to more checks (#8775)

These mostly solve false negatives for various checks, save for one false positive for `use-maxsplit-arg`.
pylint-dev · Jun 14, 2023 · 507dfc5 · 507dfc5
1 parent bafb229
commit 507dfc5
Show file tree

Hide file tree

Showing 10 changed files with 68 additions and 28 deletions.
diff --git a/doc/whatsnew/fragments/7761.false_negative b/doc/whatsnew/fragments/7761.false_negative
@@ -0,0 +1,6 @@
+Apply ``infer_kwarg_from_call()`` to more checks
+
+These mostly solve false negatives for various checks,
+save for one false positive for ``use-maxsplit-arg``.
+
+Closes #7761
diff --git a/pylint/checkers/refactoring/recommendation_checker.py b/pylint/checkers/refactoring/recommendation_checker.py
@@ -127,17 +127,22 @@ def _check_use_maxsplit_arg(self, node: nodes.Call) -> None:
         ):
             return
 
+        confidence = HIGH
         try:
             sep = utils.get_argument_from_call(node, 0, "sep")
         except utils.NoSuchArgumentError:
-            return
+            sep = utils.infer_kwarg_from_call(node, keyword="sep")
+            confidence = INFERENCE
+            if not sep:
+                return
 
         try:
             # Ignore if maxsplit arg has been set
             utils.get_argument_from_call(node, 1, "maxsplit")
             return
         except utils.NoSuchArgumentError:
-            pass
+            if utils.infer_kwarg_from_call(node, keyword="maxsplit"):
+                return
 
         if isinstance(node.parent, nodes.Subscript):
             try:
@@ -171,7 +176,12 @@ def _check_use_maxsplit_arg(self, node: nodes.Call) -> None:
                     + new_fn
                     + f"({sep.as_string()}, maxsplit=1)[{subscript_value}]"
                 )
-                self.add_message("use-maxsplit-arg", node=node, args=(new_name,))
+                self.add_message(
+                    "use-maxsplit-arg",
+                    node=node,
+                    args=(new_name,),
+                    confidence=confidence,
+                )
 
     @utils.only_required_for_messages(
         "consider-using-enumerate",

diff --git a/pylint/checkers/refactoring/refactoring_checker.py b/pylint/checkers/refactoring/refactoring_checker.py
@@ -2203,12 +2203,14 @@ def _check_unnecessary_list_index_lookup(
         ):
             return
 
+        preliminary_confidence = HIGH
         try:
             iterable_arg = utils.get_argument_from_call(
                 node.iter, position=0, keyword="iterable"
             )
         except utils.NoSuchArgumentError:
-            return
+            iterable_arg = utils.infer_kwarg_from_call(node.iter, keyword="iterable")
+            preliminary_confidence = INFERENCE
 
         if not isinstance(iterable_arg, nodes.Name):
             return
@@ -2228,6 +2230,13 @@ def _check_unnecessary_list_index_lookup(
             # is not redundant, hence we should not report an error.
             return
 
+        # Preserve preliminary_confidence if it was INFERENCE
+        confidence = (
+            preliminary_confidence
+            if preliminary_confidence == INFERENCE
+            else confidence
+        )
+
         iterating_object_name = iterable_arg.name
         value_variable = node.target.elts[1]
 

diff --git a/pylint/checkers/stdlib.py b/pylint/checkers/stdlib.py
@@ -619,7 +619,7 @@ def _check_lru_cache_decorators(self, node: nodes.FunctionDef) -> None:
                                 d_node, position=0, keyword="maxsize"
                             )
                         except utils.NoSuchArgumentError:
-                            break
+                            arg = utils.infer_kwarg_from_call(d_node, "maxsize")
 
                         if not isinstance(arg, nodes.Const) or arg.value is not None:
                             break

diff --git a/tests/functional/m/method_cache_max_size_none.py b/tests/functional/m/method_cache_max_size_none.py
@@ -45,6 +45,11 @@ def my_func(self, param):
     def my_func(self, param):
         return param + 1
 
+    maxsizeKwarg = {"maxsize": None}
+    @lru_cache(**maxsizeKwarg)  # [method-cache-max-size-none]
+    def my_func(self, param):
+        return param + 1
+
 
 class MyClassWithMethodsAndMaxSize:
     @lru_cache(maxsize=1)

diff --git a/tests/functional/m/method_cache_max_size_none.txt b/tests/functional/m/method_cache_max_size_none.txt
@@ -4,4 +4,5 @@ method-cache-max-size-none:34:5:34:38:MyClassWithMethods.my_func:'lru_cache(maxs
 method-cache-max-size-none:38:5:38:24:MyClassWithMethods.my_func:'lru_cache(maxsize=None)' or 'cache' will keep all method args alive indefinitely, including 'self':INFERENCE
 method-cache-max-size-none:43:5:43:24:MyClassWithMethods.my_func:'lru_cache(maxsize=None)' or 'cache' will keep all method args alive indefinitely, including 'self':INFERENCE
 method-cache-max-size-none:44:5:44:24:MyClassWithMethods.my_func:'lru_cache(maxsize=None)' or 'cache' will keep all method args alive indefinitely, including 'self':INFERENCE
-method-cache-max-size-none:74:5:74:40:MyClassWithMethodsAndMaxSize.my_func:'lru_cache(maxsize=None)' or 'cache' will keep all method args alive indefinitely, including 'self':INFERENCE
+method-cache-max-size-none:49:5:49:30:MyClassWithMethods.my_func:'lru_cache(maxsize=None)' or 'cache' will keep all method args alive indefinitely, including 'self':INFERENCE
+method-cache-max-size-none:79:5:79:40:MyClassWithMethodsAndMaxSize.my_func:'lru_cache(maxsize=None)' or 'cache' will keep all method args alive indefinitely, including 'self':INFERENCE
diff --git a/tests/functional/u/unnecessary/unnecessary_list_index_lookup.py b/tests/functional/u/unnecessary/unnecessary_list_index_lookup.py
@@ -136,6 +136,9 @@ def return_start(start):
 
 result = [my_list[idx] for idx, val in enumerate(iterable=my_list)]  # [unnecessary-list-index-lookup]
 
+iterable_kwarg = {"iterable": my_list}
+result = [my_list[idx] for idx, val in enumerate(**iterable_kwarg)]  # [unnecessary-list-index-lookup]
+
 for idx, val in enumerate():
     print(my_list[idx])
 

diff --git a/tests/functional/u/unnecessary/unnecessary_list_index_lookup.txt b/tests/functional/u/unnecessary/unnecessary_list_index_lookup.txt
@@ -8,3 +8,4 @@ unnecessary-list-index-lookup:119:10:119:21::Unnecessary list index lookup, use
 unnecessary-list-index-lookup:122:10:122:21::Unnecessary list index lookup, use 'val' instead:INFERENCE
 unnecessary-list-index-lookup:135:10:135:21::Unnecessary list index lookup, use 'val' instead:HIGH
 unnecessary-list-index-lookup:137:10:137:22::Unnecessary list index lookup, use 'val' instead:HIGH
+unnecessary-list-index-lookup:140:10:140:22::Unnecessary list index lookup, use 'val' instead:INFERENCE
diff --git a/tests/functional/u/use/use_maxsplit_arg.py b/tests/functional/u/use/use_maxsplit_arg.py
@@ -17,12 +17,14 @@
 
 
 # Test varying maxsplit argument -- all these will be okay
+max_split = {"maxsplit": 2}
 # ## str.split() tests
 good_split = '1,2,3'.split(sep=',', maxsplit=1)[-1]
 good_split = '1,2,3'.split(sep=',', maxsplit=1)[0]
 good_split = '1,2,3'.split(sep=',', maxsplit=2)[-1]
 good_split = '1,2,3'.split(sep=',', maxsplit=2)[0]
 good_split = '1,2,3'.split(sep=',', maxsplit=2)[1]
+good_split = '1,2,3'.split(sep=',', **max_split)[1]
 
 # ## str.rsplit() tests
 good_split = '1,2,3'.rsplit(sep=',', maxsplit=1)[-1]
@@ -91,9 +93,11 @@ class Bar():
     print(source.split('.')[i])
     i = i + 1
 
+sepNone = {"sep": None}
 # Test for crash when sep is given by keyword
 # https://github.com/pylint-dev/pylint/issues/5737
 get_last = SEQ.split(sep=None)[-1]  # [use-maxsplit-arg]
+get_last = SEQ.split(**sepNone)[-1]  # [use-maxsplit-arg]
 
 
 class FalsePositive4857:

diff --git a/tests/functional/u/use/use_maxsplit_arg.txt b/tests/functional/u/use/use_maxsplit_arg.txt
@@ -1,22 +1,23 @@
-use-maxsplit-arg:5:12:5:30::Use '1,2,3'.split(',', maxsplit=1)[0] instead:UNDEFINED
-use-maxsplit-arg:6:11:6:35::"Use '1,2,3'[::-1].split(',', maxsplit=1)[0] instead":UNDEFINED
-use-maxsplit-arg:9:12:9:26::Use SEQ.split(',', maxsplit=1)[0] instead:UNDEFINED
-use-maxsplit-arg:10:11:10:25::Use SEQ.rsplit(',', maxsplit=1)[-1] instead:UNDEFINED
-use-maxsplit-arg:11:12:11:27::Use SEQ.split(',', maxsplit=1)[0] instead:UNDEFINED
-use-maxsplit-arg:12:11:12:26::Use SEQ.rsplit(',', maxsplit=1)[-1] instead:UNDEFINED
-use-maxsplit-arg:45:12:45:36::Use Foo.class_str.split(',', maxsplit=1)[0] instead:UNDEFINED
-use-maxsplit-arg:46:11:46:35::Use Foo.class_str.rsplit(',', maxsplit=1)[-1] instead:UNDEFINED
-use-maxsplit-arg:47:12:47:37::Use Foo.class_str.split(',', maxsplit=1)[0] instead:UNDEFINED
-use-maxsplit-arg:48:11:48:36::Use Foo.class_str.rsplit(',', maxsplit=1)[-1] instead:UNDEFINED
-use-maxsplit-arg:56:12:56:40::Use test.get_string().split(',', maxsplit=1)[0] instead:UNDEFINED
-use-maxsplit-arg:57:11:57:39::Use test.get_string().rsplit(',', maxsplit=1)[-1] instead:UNDEFINED
-use-maxsplit-arg:66:10:66:22::Use s.split(' ', maxsplit=1)[0] instead:UNDEFINED
-use-maxsplit-arg:67:10:67:22::Use s.rsplit(' ', maxsplit=1)[-1] instead:UNDEFINED
-use-maxsplit-arg:76:6:76:26::Use Bar.split.split(',', maxsplit=1)[0] instead:UNDEFINED
-use-maxsplit-arg:77:6:77:26::Use Bar.split.rsplit(',', maxsplit=1)[-1] instead:UNDEFINED
-use-maxsplit-arg:78:6:78:27::Use Bar.split.split(',', maxsplit=1)[0] instead:UNDEFINED
-use-maxsplit-arg:79:6:79:27::Use Bar.split.rsplit(',', maxsplit=1)[-1] instead:UNDEFINED
-use-maxsplit-arg:82:4:82:23::Use '1,2,3'.split('\n', maxsplit=1)[0] instead:UNDEFINED
-use-maxsplit-arg:83:4:83:26::Use '1,2,3'.rsplit('split', maxsplit=1)[-1] instead:UNDEFINED
-use-maxsplit-arg:84:4:84:28::Use '1,2,3'.split('rsplit', maxsplit=1)[0] instead:UNDEFINED
-use-maxsplit-arg:96:11:96:30::Use SEQ.rsplit(None, maxsplit=1)[-1] instead:UNDEFINED
+use-maxsplit-arg:5:12:5:30::Use '1,2,3'.split(',', maxsplit=1)[0] instead:HIGH
+use-maxsplit-arg:6:11:6:35::"Use '1,2,3'[::-1].split(',', maxsplit=1)[0] instead":HIGH
+use-maxsplit-arg:9:12:9:26::Use SEQ.split(',', maxsplit=1)[0] instead:HIGH
+use-maxsplit-arg:10:11:10:25::Use SEQ.rsplit(',', maxsplit=1)[-1] instead:HIGH
+use-maxsplit-arg:11:12:11:27::Use SEQ.split(',', maxsplit=1)[0] instead:HIGH
+use-maxsplit-arg:12:11:12:26::Use SEQ.rsplit(',', maxsplit=1)[-1] instead:HIGH
+use-maxsplit-arg:47:12:47:36::Use Foo.class_str.split(',', maxsplit=1)[0] instead:HIGH
+use-maxsplit-arg:48:11:48:35::Use Foo.class_str.rsplit(',', maxsplit=1)[-1] instead:HIGH
+use-maxsplit-arg:49:12:49:37::Use Foo.class_str.split(',', maxsplit=1)[0] instead:HIGH
+use-maxsplit-arg:50:11:50:36::Use Foo.class_str.rsplit(',', maxsplit=1)[-1] instead:HIGH
+use-maxsplit-arg:58:12:58:40::Use test.get_string().split(',', maxsplit=1)[0] instead:HIGH
+use-maxsplit-arg:59:11:59:39::Use test.get_string().rsplit(',', maxsplit=1)[-1] instead:HIGH
+use-maxsplit-arg:68:10:68:22::Use s.split(' ', maxsplit=1)[0] instead:HIGH
+use-maxsplit-arg:69:10:69:22::Use s.rsplit(' ', maxsplit=1)[-1] instead:HIGH
+use-maxsplit-arg:78:6:78:26::Use Bar.split.split(',', maxsplit=1)[0] instead:HIGH
+use-maxsplit-arg:79:6:79:26::Use Bar.split.rsplit(',', maxsplit=1)[-1] instead:HIGH
+use-maxsplit-arg:80:6:80:27::Use Bar.split.split(',', maxsplit=1)[0] instead:HIGH
+use-maxsplit-arg:81:6:81:27::Use Bar.split.rsplit(',', maxsplit=1)[-1] instead:HIGH
+use-maxsplit-arg:84:4:84:23::Use '1,2,3'.split('\n', maxsplit=1)[0] instead:HIGH
+use-maxsplit-arg:85:4:85:26::Use '1,2,3'.rsplit('split', maxsplit=1)[-1] instead:HIGH
+use-maxsplit-arg:86:4:86:28::Use '1,2,3'.split('rsplit', maxsplit=1)[0] instead:HIGH
+use-maxsplit-arg:99:11:99:30::Use SEQ.rsplit(None, maxsplit=1)[-1] instead:HIGH
+use-maxsplit-arg:100:11:100:31::Use SEQ.rsplit(None, maxsplit=1)[-1] instead:INFERENCE