--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/eric6/Plugins/CheckerPlugins/CodeStyleChecker/ComplexityChecker.py Sun Apr 14 15:09:21 2019 +0200
@@ -0,0 +1,251 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2015 - 2019 Detlev Offenbach <detlev@die-offenbachs.de>
+#
+
+"""
+Module implementing a checker for code complexity.
+"""
+
+import sys
+import ast
+
+from mccabe import PathGraphingAstVisitor
+
+
+class ComplexityChecker(object):
+ """
+ Class implementing a checker for code complexity.
+ """
+ Codes = [
+ "C101",
+ "C111", "C112",
+
+ "C901",
+ ]
+
+ def __init__(self, source, filename, select, ignore, args):
+ """
+ Constructor
+
+ @param source source code to be checked
+ @type list of str
+ @param filename name of the source file
+ @type str
+ @param select list of selected codes
+ @type list of str
+ @param ignore list of codes to be ignored
+ @type list of str
+ @param args dictionary of arguments for the miscellaneous checks
+ @type dict
+ """
+ self.__filename = filename
+ self.__source = source[:]
+ self.__select = tuple(select)
+ self.__ignore = ('',) if select else tuple(ignore)
+ self.__args = args
+
+ self.__defaultArgs = {
+ "McCabeComplexity": 10,
+ "LineComplexity": 15,
+ "LineComplexityScore": 10,
+ }
+
+ # statistics counters
+ self.counters = {}
+
+ # collection of detected errors
+ self.errors = []
+
+ checkersWithCodes = [
+ (self.__checkMcCabeComplexity, ("C101",)),
+ (self.__checkLineComplexity, ("C111", "C112")),
+ ]
+
+ self.__checkers = []
+ for checker, codes in checkersWithCodes:
+ if any(not (code and self.__ignoreCode(code))
+ for code in codes):
+ self.__checkers.append(checker)
+
+ def __ignoreCode(self, code):
+ """
+ Private method to check if the message code should be ignored.
+
+ @param code message code to check for
+ @type str
+ @return flag indicating to ignore the given code
+ @rtype bool
+ """
+ return (code.startswith(self.__ignore) and
+ not code.startswith(self.__select))
+
+ def __error(self, lineNumber, offset, code, *args):
+ """
+ Private method to record an issue.
+
+ @param lineNumber line number of the issue
+ @type int
+ @param offset position within line of the issue
+ @type int
+ @param code message code
+ @type str
+ @param args arguments for the message
+ @type list
+ """
+ if self.__ignoreCode(code):
+ return
+
+ if code in self.counters:
+ self.counters[code] += 1
+ else:
+ self.counters[code] = 1
+
+ if code:
+ # record the issue with one based line number
+ self.errors.append(
+ (self.__filename, lineNumber, offset, (code, args)))
+
+ def __reportInvalidSyntax(self):
+ """
+ Private method to report a syntax error.
+ """
+ exc_type, exc = sys.exc_info()[:2]
+ if len(exc.args) > 1:
+ offset = exc.args[1]
+ if len(offset) > 2:
+ offset = offset[1:3]
+ else:
+ offset = (1, 0)
+ self.__error(offset[0] - 1, offset[1] or 0,
+ 'C901', exc_type.__name__, exc.args[0])
+
+ def run(self):
+ """
+ Public method to check the given source for code complexity.
+ """
+ if not self.__filename or not self.__source:
+ # don't do anything, if essential data is missing
+ return
+
+ if not self.__checkers:
+ # don't do anything, if no codes were selected
+ return
+
+ try:
+ self.__tree = compile(''.join(self.__source), self.__filename,
+ 'exec', ast.PyCF_ONLY_AST)
+ except (SyntaxError, TypeError):
+ self.__reportInvalidSyntax()
+ return
+
+ for check in self.__checkers:
+ check()
+
+ def __checkMcCabeComplexity(self):
+ """
+ Private method to check the McCabe code complexity.
+ """
+ try:
+ # create the AST again because it is modified by the checker
+ tree = compile(''.join(self.__source), self.__filename, 'exec',
+ ast.PyCF_ONLY_AST)
+ except (SyntaxError, TypeError):
+ # compile errors are already reported by the run() method
+ return
+
+ maxComplexity = self.__args.get("McCabeComplexity",
+ self.__defaultArgs["McCabeComplexity"])
+
+ visitor = PathGraphingAstVisitor()
+ visitor.preorder(tree, visitor)
+ for graph in visitor.graphs.values():
+ if graph.complexity() > maxComplexity:
+ self.__error(graph.lineno, 0, "C101",
+ graph.entity, graph.complexity())
+
+ def __checkLineComplexity(self):
+ """
+ Private method to check the complexity of a single line of code and
+ the median line complexity of the source code.
+
+ Complexity is defined as the number of AST nodes produced by a line
+ of code.
+ """
+ maxLineComplexity = self.__args.get(
+ "LineComplexity", self.__defaultArgs["LineComplexity"])
+ maxLineComplexityScore = self.__args.get(
+ "LineComplexityScore", self.__defaultArgs["LineComplexityScore"])
+
+ visitor = LineComplexityVisitor()
+ visitor.visit(self.__tree)
+
+ sortedItems = visitor.sortedList()
+ score = visitor.score()
+
+ for line, complexity in sortedItems:
+ if complexity > maxLineComplexity:
+ self.__error(line, 0, "C111", complexity)
+
+ if score > maxLineComplexityScore:
+ self.__error(0, 0, "C112", score)
+
+
+class LineComplexityVisitor(ast.NodeVisitor):
+ """
+ Class calculating the number of AST nodes per line of code
+ and the median nodes/line score.
+ """
+ def __init__(self):
+ """
+ Constructor
+ """
+ super(LineComplexityVisitor, self).__init__()
+ self.__count = {}
+
+ def visit(self, node):
+ """
+ Public method to recursively visit all the nodes and add up the
+ instructions.
+
+ @param node reference to the node
+ @type ast.AST
+ """
+ if hasattr(node, 'lineno'):
+ self.__count[node.lineno] = self.__count.get(node.lineno, 0) + 1
+ self.generic_visit(node)
+
+ def sortedList(self):
+ """
+ Public method to get a sorted list of (line, nodes) tuples.
+
+ @return sorted list of (line, nodes) tuples
+ @rtype list of tuple of (int,int)
+ """
+ lst = [(line, self.__count[line])
+ for line in sorted(self.__count.keys())]
+ return lst
+
+ def score(self):
+ """
+ Public method to calculate the median.
+
+ @return median line complexity value
+ @rtype float
+ """
+ lst = self.__count.values()
+ sortedList = sorted(lst)
+ listLength = len(lst)
+ medianIndex = (listLength - 1) // 2
+
+ if listLength == 0:
+ return 0.0
+ elif (listLength % 2):
+ return float(sortedList[medianIndex])
+ else:
+ return (
+ (sortedList[medianIndex] + sortedList[medianIndex + 1]) / 2.0
+ )
+
+#
+# eflag: noqa = M702
