1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
# Copyright (c) 2016-2017 Claudiu Popa <pcmanticore@gmail.com>
# Copyright (c) 2016 Moises Lopez <moylop260@vauxoo.com>
# Copyright (c) 2017 hippo91 <guillaume.peillex@gmail.com>
# 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(PathGraph, self).__init__(name="", entity="", lineno=1)
self.root = node
class PathGraphingAstVisitor(Mccabe_PathGraphingAstVisitor):
def __init__(self):
super(PathGraphingAstVisitor, self).__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))
|
