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venv/lib/python3.8/site-packages/pylint/extensions/mccabe.py

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+# Copyright (c) 2016-2019 Claudiu Popa <pcmanticore@gmail.com>
+# Copyright (c) 2016 Moises Lopez <moylop260@vauxoo.com>
+# Copyright (c) 2017 hippo91 <guillaume.peillex@gmail.com>
+# Copyright (c) 2019 Hugo van Kemenade <hugovk@users.noreply.github.com>
+# Copyright (c) 2019 Pierre Sassoulas <pierre.sassoulas@gmail.com>
+# Copyright (c) 2020 Anthony Sottile <asottile@umich.edu>
+
+# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+# For details: https://github.com/PyCQA/pylint/blob/master/COPYING
+
+"""Module to add McCabe checker class for pylint. """
+
+from mccabe import PathGraph as Mccabe_PathGraph
+from mccabe import PathGraphingAstVisitor as Mccabe_PathGraphingAstVisitor
+
+from pylint import checkers
+from pylint.checkers.utils import check_messages
+from pylint.interfaces import HIGH, IAstroidChecker
+
+
+class PathGraph(Mccabe_PathGraph):
+    def __init__(self, node):
+        super().__init__(name="", entity="", lineno=1)
+        self.root = node
+
+
+class PathGraphingAstVisitor(Mccabe_PathGraphingAstVisitor):
+    def __init__(self):
+        super().__init__()
+        self._bottom_counter = 0
+
+    def default(self, node, *args):
+        for child in node.get_children():
+            self.dispatch(child, *args)
+
+    def dispatch(self, node, *args):
+        self.node = node
+        klass = node.__class__
+        meth = self._cache.get(klass)
+        if meth is None:
+            class_name = klass.__name__
+            meth = getattr(self.visitor, "visit" + class_name, self.default)
+            self._cache[klass] = meth
+        return meth(node, *args)
+
+    def visitFunctionDef(self, node):
+        if self.graph is not None:
+            # closure
+            pathnode = self._append_node(node)
+            self.tail = pathnode
+            self.dispatch_list(node.body)
+            bottom = "%s" % self._bottom_counter
+            self._bottom_counter += 1
+            self.graph.connect(self.tail, bottom)
+            self.graph.connect(node, bottom)
+            self.tail = bottom
+        else:
+            self.graph = PathGraph(node)
+            self.tail = node
+            self.dispatch_list(node.body)
+            self.graphs["%s%s" % (self.classname, node.name)] = self.graph
+            self.reset()
+
+    visitAsyncFunctionDef = visitFunctionDef
+
+    def visitSimpleStatement(self, node):
+        self._append_node(node)
+
+    visitAssert = (
+        visitAssign
+    ) = (
+        visitAugAssign
+    ) = (
+        visitDelete
+    ) = (
+        visitPrint
+    ) = (
+        visitRaise
+    ) = (
+        visitYield
+    ) = (
+        visitImport
+    ) = (
+        visitCall
+    ) = (
+        visitSubscript
+    ) = (
+        visitPass
+    ) = (
+        visitContinue
+    ) = (
+        visitBreak
+    ) = visitGlobal = visitReturn = visitExpr = visitAwait = visitSimpleStatement
+
+    def visitWith(self, node):
+        self._append_node(node)
+        self.dispatch_list(node.body)
+
+    visitAsyncWith = visitWith
+
+    def _append_node(self, node):
+        if not self.tail:
+            return None
+        self.graph.connect(self.tail, node)
+        self.tail = node
+        return node
+
+    def _subgraph(self, node, name, extra_blocks=()):
+        """create the subgraphs representing any `if` and `for` statements"""
+        if self.graph is None:
+            # global loop
+            self.graph = PathGraph(node)
+            self._subgraph_parse(node, node, extra_blocks)
+            self.graphs["%s%s" % (self.classname, name)] = self.graph
+            self.reset()
+        else:
+            self._append_node(node)
+            self._subgraph_parse(node, node, extra_blocks)
+
+    def _subgraph_parse(self, node, pathnode, extra_blocks):
+        """parse the body and any `else` block of `if` and `for` statements"""
+        loose_ends = []
+        self.tail = node
+        self.dispatch_list(node.body)
+        loose_ends.append(self.tail)
+        for extra in extra_blocks:
+            self.tail = node
+            self.dispatch_list(extra.body)
+            loose_ends.append(self.tail)
+        if node.orelse:
+            self.tail = node
+            self.dispatch_list(node.orelse)
+            loose_ends.append(self.tail)
+        else:
+            loose_ends.append(node)
+        if node:
+            bottom = "%s" % self._bottom_counter
+            self._bottom_counter += 1
+            for end in loose_ends:
+                self.graph.connect(end, bottom)
+            self.tail = bottom
+
+
+class McCabeMethodChecker(checkers.BaseChecker):
+    """Checks McCabe complexity cyclomatic threshold in methods and functions
+    to validate a too complex code.
+    """
+
+    __implements__ = IAstroidChecker
+    name = "design"
+
+    msgs = {
+        "R1260": (
+            "%s is too complex. The McCabe rating is %d",
+            "too-complex",
+            "Used when a method or function is too complex based on "
+            "McCabe Complexity Cyclomatic",
+        )
+    }
+    options = (
+        (
+            "max-complexity",
+            {
+                "default": 10,
+                "type": "int",
+                "metavar": "<int>",
+                "help": "McCabe complexity cyclomatic threshold",
+            },
+        ),
+    )
+
+    @check_messages("too-complex")
+    def visit_module(self, node):
+        """visit an astroid.Module node to check too complex rating and
+        add message if is greather than max_complexity stored from options"""
+        visitor = PathGraphingAstVisitor()
+        for child in node.body:
+            visitor.preorder(child, visitor)
+        for graph in visitor.graphs.values():
+            complexity = graph.complexity()
+            node = graph.root
+            if hasattr(node, "name"):
+                node_name = "'%s'" % node.name
+            else:
+                node_name = "This '%s'" % node.__class__.__name__.lower()
+            if complexity <= self.config.max_complexity:
+                continue
+            self.add_message(
+                "too-complex", node=node, confidence=HIGH, args=(node_name, complexity)
+            )
+
+
+def register(linter):
+    """Required method to auto register this checker.
+
+    :param linter: Main interface object for Pylint plugins
+    :type linter: Pylint object
+    """
+    linter.register_checker(McCabeMethodChecker(linter))