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comparison: src/eric7/Plugins/CheckerPlugins/CodeStyleChecker/Miscellaneous/DefaultMatchCaseVisitor.py
src/eric7/Plugins/CheckerPlugins/CodeStyleChecker/Miscellaneous/DefaultMatchCaseVisitor.py
- branch
- eric7
- changeset 11150
- 73d80859079c
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| 11149:fc45672fae42 | 11150:73d80859079c |
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| 1 # -*- coding: utf-8 -*- | |
| 2 | |
| 3 # Copyright (c) 2025 Detlev Offenbach <detlev@die-offenbachs.de> | |
| 4 # | |
| 5 | |
| 6 """ | |
| 7 Module implementing a node visitor to check default match cases. | |
| 8 """ | |
| 9 | |
| 10 import ast | |
| 11 | |
| 12 | |
| 13 class DefaultMatchCaseVisitor(ast.NodeVisitor): | |
| 14 """ | |
| 15 Class implementing a node visitor to check default match cases. | |
| 16 | |
| 17 Note: This class is modeled after flake8-spm v0.0.1. | |
| 18 """ | |
| 19 | |
| 20 def __init__(self): | |
| 21 """ | |
| 22 Constructor | |
| 23 """ | |
| 24 super().__init__() | |
| 25 | |
| 26 self.violations = [] | |
| 27 | |
| 28 def visit_Match(self, node): | |
| 29 """ | |
| 30 Public method to handle Match nodes. | |
| 31 | |
| 32 @param node reference to the node to be processed | |
| 33 @type ast.Match | |
| 34 """ | |
| 35 for badNode, issueCode in self.__badNodes(node): | |
| 36 self.violations.append((badNode, issueCode)) | |
| 37 | |
| 38 self.generic_visit(node) | |
| 39 | |
| 40 def __badNodes(self, node): | |
| 41 """ | |
| 42 Private method to yield bad match nodes. | |
| 43 | |
| 44 @param node reference to the node to be processed | |
| 45 @type ast.Match | |
| 46 @yield tuple containing a reference to bad match case node and the corresponding | |
| 47 issue code | |
| 48 @ytype tyuple of (ast.AST, str) | |
| 49 """ | |
| 50 for case in node.cases: | |
| 51 if self.__emptyMatchDefault(case): | |
| 52 if self.__lastStatementDoesNotRaise(case): | |
| 53 yield self.__findBadNode(case), "M-901" | |
| 54 elif self.__returnPrecedesExceptionRaising(case): | |
| 55 yield self.__findBadNode(case), "M-902" | |
| 56 | |
| 57 def __emptyMatchDefault(self, case): | |
| 58 """ | |
| 59 Private method to check for an empty default match case. | |
| 60 | |
| 61 @param case reference to the node to be processed | |
| 62 @type ast.match_case | |
| 63 @return flag indicating an empty default match case | |
| 64 @rtype bool | |
| 65 """ | |
| 66 pattern = case.pattern | |
| 67 return isinstance(pattern, ast.MatchAs) and ( | |
| 68 pattern.pattern is None | |
| 69 or ( | |
| 70 isinstance(pattern.pattern, ast.MatchAs) | |
| 71 and pattern.pattern.pattern is None | |
| 72 ) | |
| 73 ) | |
| 74 | |
| 75 def __lastStatementDoesNotRaise(self, case): | |
| 76 """ | |
| 77 Private method to check that the last case statement does not raise an | |
| 78 exception. | |
| 79 | |
| 80 @param case reference to the node to be processed | |
| 81 @type ast.match_case | |
| 82 @return flag indicating that the last case statement does not raise an | |
| 83 exception | |
| 84 @rtype bool | |
| 85 """ | |
| 86 return not isinstance(case.body[-1], ast.Raise) | |
| 87 | |
| 88 def __returnPrecedesExceptionRaising(self, case): | |
| 89 """ | |
| 90 Private method to check that no return precedes an exception raising. | |
| 91 | |
| 92 @param case reference to the node to be processed | |
| 93 @type ast.match_case | |
| 94 @return flag indicating that a return precedes an exception raising | |
| 95 @rtype bool | |
| 96 """ | |
| 97 returnIndex = -1 | |
| 98 raiseIndex = -1 | |
| 99 for index, body in enumerate(case.body): | |
| 100 if isinstance(body, ast.Return): | |
| 101 returnIndex = index | |
| 102 elif isinstance(body, ast.Raise): | |
| 103 raiseIndex = index | |
| 104 return returnIndex >= 0 and returnIndex < raiseIndex | |
| 105 | |
| 106 def __findBadNode(self, case) -> ast.AST: | |
| 107 """ | |
| 108 Private method returning a reference to the bad node of a case node. | |
| 109 | |
| 110 @param case reference to the node to be processed | |
| 111 @type ast.match_case | |
| 112 @return reference to the bad node | |
| 113 @rtype ast.AST | |
| 114 """ | |
| 115 for body in case.body: | |
| 116 # Handle special case when return precedes exception raising. | |
| 117 # In this case the bad node is that with the return statement. | |
| 118 if isinstance(body, ast.Return): | |
| 119 return body | |
| 120 | |
| 121 return case.body[-1] |
