diff options
Diffstat (limited to 'checkers/design_analysis.py')
| -rw-r--r-- | checkers/design_analysis.py | 53 |
1 files changed, 52 insertions, 1 deletions
diff --git a/checkers/design_analysis.py b/checkers/design_analysis.py index 2d40e8d17..daa550a71 100644 --- a/checkers/design_analysis.py +++ b/checkers/design_analysis.py @@ -30,6 +30,44 @@ import re # regexp for ignored argument name IGNORED_ARGUMENT_NAMES = re.compile('_.*') +SPECIAL_METHODS = [('Context manager', set(('__enter__', + '__exit__',))), + ('Container', set(('__len__', + '__getitem__', + '__setitem__', + '__delitem__',))), + ('Callable', set(('__call__',))), + ] + +class SpecialMethodChecker(object): + """A functor that checks for consistency of a set of special methods""" + def __init__(self, methods_found, on_error): + """Stores the set of __x__ method names that were found in the + class and a callable that will be called with args to R0024 if + the check fails + """ + self.methods_found = methods_found + self.on_error = on_error + + def __call__(self, methods_required, protocol): + """Checks the set of method names given to __init__ against the set + required. + + If they are all present, returns true. + If they are all absent, returns false. + If some are present, reports the error and returns false. + """ + required_methods_found = methods_required & self.methods_found + if required_methods_found == methods_required: + return True + if required_methods_found != set(): + required_methods_missing = methods_required - self.methods_found + self.on_error((protocol, + ', '.join(sorted(required_methods_found)), + ', '.join(sorted(required_methods_missing)))) + return False + + def class_is_abstract(klass): """return true if the given class node should be considered as an abstract class @@ -88,6 +126,10 @@ MSGS = { 'R0923': ('Interface not implemented', 'interface-not-implemented', 'Used when an interface class is not implemented anywhere.'), + 'R0924': ('Badly implemented %s, implements %s but not %s', + 'incomplete-protocol', + 'A class implements some of the special methods for a particular \ + protocol, but not all of them') } @@ -235,9 +277,12 @@ class MisdesignChecker(BaseChecker): def leave_class(self, node): """check number of public methods""" nb_public_methods = 0 + special_methods = set() for method in node.methods(): if not method.name.startswith('_'): nb_public_methods += 1 + if method.name.startswith("__"): + special_methods.add(method.name) # Does the class contain less than 20 public methods ? if nb_public_methods > self.config.max_public_methods: self.add_message('R0904', node=node, @@ -246,13 +291,19 @@ class MisdesignChecker(BaseChecker): # stop here for exception, metaclass and interface classes if node.type != 'class': return + # Does the class implement special methods consitently? + # If so, don't enforce minimum public methods. + check_special = SpecialMethodChecker( + special_methods, lambda args: self.add_message('R0924', node=node, args=args)) + protocols = [check_special(pmethods, pname) for pname, pmethods in SPECIAL_METHODS] + if True in protocols: + return # Does the class contain more than 5 public methods ? if nb_public_methods < self.config.min_public_methods: self.add_message('R0903', node=node, args=(nb_public_methods, self.config.min_public_methods)) - def visit_function(self, node): """check function name, docstring, arguments, redefinition, variable names, max locals |