# Copyright (c) 2007-2013 LOGILAB S.A. (Paris, FRANCE) # Copyright (c) 2010 Daniel Harding # Copyright (c) 2014-2016, 2018-2020 Claudiu Popa # Copyright (c) 2014 Google, Inc. # Copyright (c) 2015-2016 Ceridwen # Copyright (c) 2019 Ashley Whetter # Copyright (c) 2019 Hugo van Kemenade # Copyright (c) 2020-2021 hippo91 # Copyright (c) 2021 Pierre Sassoulas # Copyright (c) 2021 Daniël van Noord <13665637+DanielNoord@users.noreply.github.com> # Copyright (c) 2021 David Liu # Copyright (c) 2021 Marc Mueller <30130371+cdce8p@users.noreply.github.com> # Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html # For details: https://github.com/PyCQA/astroid/blob/main/LICENSE """tests for the astroid variable lookup capabilities """ import functools import unittest from astroid import builder, nodes, test_utils from astroid.exceptions import ( AttributeInferenceError, InferenceError, NameInferenceError, ) from . import resources class LookupTest(resources.SysPathSetup, unittest.TestCase): def setUp(self) -> None: super().setUp() self.module = resources.build_file("data/module.py", "data.module") self.module2 = resources.build_file("data/module2.py", "data.module2") self.nonregr = resources.build_file("data/nonregr.py", "data.nonregr") def test_limit(self) -> None: code = """ l = [a for a,b in list] a = 1 b = a a = None def func(): c = 1 """ astroid = builder.parse(code, __name__) # a & b a = next(astroid.nodes_of_class(nodes.Name)) self.assertEqual(a.lineno, 2) self.assertEqual(len(astroid.lookup("b")[1]), 1) self.assertEqual(len(astroid.lookup("a")[1]), 1) b = astroid.locals["b"][0] stmts = a.lookup("a")[1] self.assertEqual(len(stmts), 1) self.assertEqual(b.lineno, 6) b_infer = b.infer() b_value = next(b_infer) self.assertEqual(b_value.value, 1) # c self.assertRaises(StopIteration, functools.partial(next, b_infer)) func = astroid.locals["func"][0] self.assertEqual(len(func.lookup("c")[1]), 1) def test_module(self) -> None: astroid = builder.parse("pass", __name__) # built-in objects none = next(astroid.ilookup("None")) self.assertIsNone(none.value) obj = next(astroid.ilookup("object")) self.assertIsInstance(obj, nodes.ClassDef) self.assertEqual(obj.name, "object") self.assertRaises( InferenceError, functools.partial(next, astroid.ilookup("YOAA")) ) # XXX self.assertEqual(len(list(self.nonregr.ilookup("enumerate"))), 2) def test_class_ancestor_name(self) -> None: code = """ class A: pass class A(A): pass """ astroid = builder.parse(code, __name__) cls1 = astroid.locals["A"][0] cls2 = astroid.locals["A"][1] name = next(cls2.nodes_of_class(nodes.Name)) self.assertEqual(next(name.infer()), cls1) ### backport those test to inline code def test_method(self) -> None: method = self.module["YOUPI"]["method"] my_dict = next(method.ilookup("MY_DICT")) self.assertTrue(isinstance(my_dict, nodes.Dict), my_dict) none = next(method.ilookup("None")) self.assertIsNone(none.value) self.assertRaises( InferenceError, functools.partial(next, method.ilookup("YOAA")) ) def test_function_argument_with_default(self) -> None: make_class = self.module2["make_class"] base = next(make_class.ilookup("base")) self.assertTrue(isinstance(base, nodes.ClassDef), base.__class__) self.assertEqual(base.name, "YO") self.assertEqual(base.root().name, "data.module") def test_class(self) -> None: klass = self.module["YOUPI"] my_dict = next(klass.ilookup("MY_DICT")) self.assertIsInstance(my_dict, nodes.Dict) none = next(klass.ilookup("None")) self.assertIsNone(none.value) obj = next(klass.ilookup("object")) self.assertIsInstance(obj, nodes.ClassDef) self.assertEqual(obj.name, "object") self.assertRaises( InferenceError, functools.partial(next, klass.ilookup("YOAA")) ) def test_inner_classes(self) -> None: ddd = list(self.nonregr["Ccc"].ilookup("Ddd")) self.assertEqual(ddd[0].name, "Ddd") def test_loopvar_hiding(self) -> None: astroid = builder.parse( """ x = 10 for x in range(5): print (x) if x > 0: print ('#' * x) """, __name__, ) xnames = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"] # inside the loop, only one possible assignment self.assertEqual(len(xnames[0].lookup("x")[1]), 1) # outside the loop, two possible assignments self.assertEqual(len(xnames[1].lookup("x")[1]), 2) self.assertEqual(len(xnames[2].lookup("x")[1]), 2) def test_list_comps(self) -> None: astroid = builder.parse( """ print ([ i for i in range(10) ]) print ([ i for i in range(10) ]) print ( list( i for i in range(10) ) ) """, __name__, ) xnames = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "i"] self.assertEqual(len(xnames[0].lookup("i")[1]), 1) self.assertEqual(xnames[0].lookup("i")[1][0].lineno, 2) self.assertEqual(len(xnames[1].lookup("i")[1]), 1) self.assertEqual(xnames[1].lookup("i")[1][0].lineno, 3) self.assertEqual(len(xnames[2].lookup("i")[1]), 1) self.assertEqual(xnames[2].lookup("i")[1][0].lineno, 4) def test_list_comp_target(self) -> None: """test the list comprehension target""" astroid = builder.parse( """ ten = [ var for var in range(10) ] var """ ) var = astroid.body[1].value self.assertRaises(NameInferenceError, var.inferred) def test_dict_comps(self) -> None: astroid = builder.parse( """ print ({ i: j for i in range(10) for j in range(10) }) print ({ i: j for i in range(10) for j in range(10) }) """, __name__, ) xnames = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "i"] self.assertEqual(len(xnames[0].lookup("i")[1]), 1) self.assertEqual(xnames[0].lookup("i")[1][0].lineno, 2) self.assertEqual(len(xnames[1].lookup("i")[1]), 1) self.assertEqual(xnames[1].lookup("i")[1][0].lineno, 3) xnames = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "j"] self.assertEqual(len(xnames[0].lookup("i")[1]), 1) self.assertEqual(xnames[0].lookup("i")[1][0].lineno, 2) self.assertEqual(len(xnames[1].lookup("i")[1]), 1) self.assertEqual(xnames[1].lookup("i")[1][0].lineno, 3) def test_set_comps(self) -> None: astroid = builder.parse( """ print ({ i for i in range(10) }) print ({ i for i in range(10) }) """, __name__, ) xnames = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "i"] self.assertEqual(len(xnames[0].lookup("i")[1]), 1) self.assertEqual(xnames[0].lookup("i")[1][0].lineno, 2) self.assertEqual(len(xnames[1].lookup("i")[1]), 1) self.assertEqual(xnames[1].lookup("i")[1][0].lineno, 3) def test_set_comp_closure(self) -> None: astroid = builder.parse( """ ten = { var for var in range(10) } var """ ) var = astroid.body[1].value self.assertRaises(NameInferenceError, var.inferred) def test_list_comp_nested(self) -> None: astroid = builder.parse( """ x = [[i + j for j in range(20)] for i in range(10)] """, __name__, ) xnames = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "i"] self.assertEqual(len(xnames[0].lookup("i")[1]), 1) self.assertEqual(xnames[0].lookup("i")[1][0].lineno, 3) def test_dict_comp_nested(self) -> None: astroid = builder.parse( """ x = {i: {i: j for j in range(20)} for i in range(10)} x3 = [{i + j for j in range(20)} # Can't do nested sets for i in range(10)] """, __name__, ) xnames = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "i"] self.assertEqual(len(xnames[0].lookup("i")[1]), 1) self.assertEqual(xnames[0].lookup("i")[1][0].lineno, 3) self.assertEqual(len(xnames[1].lookup("i")[1]), 1) self.assertEqual(xnames[1].lookup("i")[1][0].lineno, 3) def test_set_comp_nested(self) -> None: astroid = builder.parse( """ x = [{i + j for j in range(20)} # Can't do nested sets for i in range(10)] """, __name__, ) xnames = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "i"] self.assertEqual(len(xnames[0].lookup("i")[1]), 1) self.assertEqual(xnames[0].lookup("i")[1][0].lineno, 3) def test_lambda_nested(self) -> None: astroid = builder.parse( """ f = lambda x: ( lambda y: x + y) """ ) xnames = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"] self.assertEqual(len(xnames[0].lookup("x")[1]), 1) self.assertEqual(xnames[0].lookup("x")[1][0].lineno, 2) def test_function_nested(self) -> None: astroid = builder.parse( """ def f1(x): def f2(y): return x + y return f2 """ ) xnames = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"] self.assertEqual(len(xnames[0].lookup("x")[1]), 1) self.assertEqual(xnames[0].lookup("x")[1][0].lineno, 2) def test_class_variables(self) -> None: # Class variables are NOT available within nested scopes. astroid = builder.parse( """ class A: a = 10 def f1(self): return a # a is not defined f2 = lambda: a # a is not defined b = [a for _ in range(10)] # a is not defined class _Inner: inner_a = a + 1 """ ) names = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "a"] self.assertEqual(len(names), 4) for name in names: self.assertRaises(NameInferenceError, name.inferred) def test_class_in_function(self) -> None: # Function variables are available within classes, including methods astroid = builder.parse( """ def f(): x = 10 class A: a = x def f1(self): return x f2 = lambda: x b = [x for _ in range(10)] class _Inner: inner_a = x + 1 """ ) names = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"] self.assertEqual(len(names), 5) for name in names: self.assertEqual(len(name.lookup("x")[1]), 1, repr(name)) self.assertEqual(name.lookup("x")[1][0].lineno, 3, repr(name)) def test_generator_attributes(self) -> None: tree = builder.parse( """ def count(): "test" yield 0 iterer = count() num = iterer.next() """ ) next_node = tree.body[2].value.func gener = next_node.expr.inferred()[0] self.assertIsInstance(gener.getattr("__next__")[0], nodes.FunctionDef) self.assertIsInstance(gener.getattr("send")[0], nodes.FunctionDef) self.assertIsInstance(gener.getattr("throw")[0], nodes.FunctionDef) self.assertIsInstance(gener.getattr("close")[0], nodes.FunctionDef) def test_explicit___name__(self) -> None: code = """ class Pouet: __name__ = "pouet" p1 = Pouet() class PouetPouet(Pouet): pass p2 = Pouet() class NoName: pass p3 = NoName() """ astroid = builder.parse(code, __name__) p1 = next(astroid["p1"].infer()) self.assertTrue(p1.getattr("__name__")) p2 = next(astroid["p2"].infer()) self.assertTrue(p2.getattr("__name__")) self.assertTrue(astroid["NoName"].getattr("__name__")) p3 = next(astroid["p3"].infer()) self.assertRaises(AttributeInferenceError, p3.getattr, "__name__") def test_function_module_special(self) -> None: astroid = builder.parse( ''' def initialize(linter): """initialize linter with checkers in this package """ package_load(linter, __path__[0]) ''', "data.__init__", ) path = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "__path__"][ 0 ] self.assertEqual(len(path.lookup("__path__")[1]), 1) def test_builtin_lookup(self) -> None: self.assertEqual(nodes.builtin_lookup("__dict__")[1], ()) intstmts = nodes.builtin_lookup("int")[1] self.assertEqual(len(intstmts), 1) self.assertIsInstance(intstmts[0], nodes.ClassDef) self.assertEqual(intstmts[0].name, "int") self.assertIs(intstmts[0], nodes.const_factory(1)._proxied) def test_decorator_arguments_lookup(self) -> None: code = """ def decorator(value): def wrapper(function): return function return wrapper class foo: member = 10 #@ @decorator(member) #This will cause pylint to complain def test(self): pass """ node = builder.extract_node(code, __name__) assert isinstance(node, nodes.Assign) member = node.targets[0] it = member.infer() obj = next(it) self.assertIsInstance(obj, nodes.Const) self.assertEqual(obj.value, 10) self.assertRaises(StopIteration, functools.partial(next, it)) def test_inner_decorator_member_lookup(self) -> None: code = """ class FileA: def decorator(bla): return bla @__(decorator) def funcA(): return 4 """ decname = builder.extract_node(code, __name__) it = decname.infer() obj = next(it) self.assertIsInstance(obj, nodes.FunctionDef) self.assertRaises(StopIteration, functools.partial(next, it)) def test_static_method_lookup(self) -> None: code = """ class FileA: @staticmethod def funcA(): return 4 class Test: FileA = [1,2,3] def __init__(self): print (FileA.funcA()) """ astroid = builder.parse(code, __name__) it = astroid["Test"]["__init__"].ilookup("FileA") obj = next(it) self.assertIsInstance(obj, nodes.ClassDef) self.assertRaises(StopIteration, functools.partial(next, it)) def test_global_delete(self) -> None: code = """ def run2(): f = Frobble() class Frobble: pass Frobble.mumble = True del Frobble def run1(): f = Frobble() """ astroid = builder.parse(code, __name__) stmts = astroid["run2"].lookup("Frobbel")[1] self.assertEqual(len(stmts), 0) stmts = astroid["run1"].lookup("Frobbel")[1] self.assertEqual(len(stmts), 0) class LookupControlFlowTest(unittest.TestCase): """Tests for lookup capabilities and control flow""" def test_consecutive_assign(self) -> None: """When multiple assignment statements are in the same block, only the last one is returned. """ code = """ x = 10 x = 100 print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 1) self.assertEqual(stmts[0].lineno, 3) def test_assign_after_use(self) -> None: """An assignment statement appearing after the variable is not returned.""" code = """ print(x) x = 10 """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 0) def test_del_removes_prior(self) -> None: """Delete statement removes any prior assignments""" code = """ x = 10 del x print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 0) def test_del_no_effect_after(self) -> None: """Delete statement doesn't remove future assignments""" code = """ x = 10 del x x = 100 print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 1) self.assertEqual(stmts[0].lineno, 4) def test_if_assign(self) -> None: """Assignment in if statement is added to lookup results, but does not replace prior assignments. """ code = """ def f(b): x = 10 if b: x = 100 print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 2) self.assertCountEqual([stmt.lineno for stmt in stmts], [3, 5]) def test_if_assigns_same_branch(self) -> None: """When if branch has multiple assignment statements, only the last one is added. """ code = """ def f(b): x = 10 if b: x = 100 x = 1000 print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 2) self.assertCountEqual([stmt.lineno for stmt in stmts], [3, 6]) def test_if_assigns_different_branch(self) -> None: """When different branches have assignment statements, the last one in each branch is added. """ code = """ def f(b): x = 10 if b == 1: x = 100 x = 1000 elif b == 2: x = 3 elif b == 3: x = 4 print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 4) self.assertCountEqual([stmt.lineno for stmt in stmts], [3, 6, 8, 10]) def test_assign_exclusive(self) -> None: """When the variable appears inside a branch of an if statement, no assignment statements from other branches are returned. """ code = """ def f(b): x = 10 if b == 1: x = 100 x = 1000 elif b == 2: x = 3 elif b == 3: x = 4 else: print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 1) self.assertEqual(stmts[0].lineno, 3) def test_assign_not_exclusive(self) -> None: """When the variable appears inside a branch of an if statement, only the last assignment statement in the same branch is returned. """ code = """ def f(b): x = 10 if b == 1: x = 100 x = 1000 elif b == 2: x = 3 elif b == 3: x = 4 print(x) else: x = 5 """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 1) self.assertEqual(stmts[0].lineno, 10) def test_if_else(self) -> None: """When an assignment statement appears in both an if and else branch, both are added. This does NOT replace an assignment statement appearing before the if statement. (See issue #213) """ code = """ def f(b): x = 10 if b: x = 100 else: x = 1000 print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 3) self.assertCountEqual([stmt.lineno for stmt in stmts], [3, 5, 7]) def test_if_variable_in_condition_1(self) -> None: """Test lookup works correctly when a variable appears in an if condition.""" code = """ x = 10 if x > 10: print('a') elif x > 0: print('b') """ astroid = builder.parse(code) x_name1, x_name2 = ( n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x" ) _, stmts1 = x_name1.lookup("x") self.assertEqual(len(stmts1), 1) self.assertEqual(stmts1[0].lineno, 2) _, stmts2 = x_name2.lookup("x") self.assertEqual(len(stmts2), 1) self.assertEqual(stmts2[0].lineno, 2) def test_if_variable_in_condition_2(self) -> None: """Test lookup works correctly when a variable appears in an if condition, and the variable is reassigned in each branch. This is based on PyCQA/pylint issue #3711. """ code = """ x = 10 if x > 10: x = 100 elif x > 0: x = 200 elif x > -10: x = 300 else: x = 400 """ astroid = builder.parse(code) x_names = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"] # All lookups should refer only to the initial x = 10. for x_name in x_names: _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 1) self.assertEqual(stmts[0].lineno, 2) def test_del_not_exclusive(self) -> None: """A delete statement in an if statement branch removes all previous assignment statements when the delete statement is not exclusive with the variable (e.g., when the variable is used below the if statement). """ code = """ def f(b): x = 10 if b == 1: x = 100 elif b == 2: del x elif b == 3: x = 4 # Only this assignment statement is returned print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 1) self.assertEqual(stmts[0].lineno, 9) def test_del_exclusive(self) -> None: """A delete statement in an if statement branch that is exclusive with the variable does not remove previous assignment statements. """ code = """ def f(b): x = 10 if b == 1: x = 100 elif b == 2: del x else: print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 1) self.assertEqual(stmts[0].lineno, 3) def test_assign_after_param(self) -> None: """When an assignment statement overwrites a function parameter, only the assignment is returned, even when the variable and assignment do not have the same parent. """ code = """ def f1(x): x = 100 print(x) def f2(x): x = 100 if True: print(x) """ astroid = builder.parse(code) x_name1, x_name2 = ( n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x" ) _, stmts1 = x_name1.lookup("x") self.assertEqual(len(stmts1), 1) self.assertEqual(stmts1[0].lineno, 3) _, stmts2 = x_name2.lookup("x") self.assertEqual(len(stmts2), 1) self.assertEqual(stmts2[0].lineno, 7) def test_assign_after_kwonly_param(self) -> None: """When an assignment statement overwrites a function keyword-only parameter, only the assignment is returned, even when the variable and assignment do not have the same parent. """ code = """ def f1(*, x): x = 100 print(x) def f2(*, x): x = 100 if True: print(x) """ astroid = builder.parse(code) x_name1, x_name2 = ( n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x" ) _, stmts1 = x_name1.lookup("x") self.assertEqual(len(stmts1), 1) self.assertEqual(stmts1[0].lineno, 3) _, stmts2 = x_name2.lookup("x") self.assertEqual(len(stmts2), 1) self.assertEqual(stmts2[0].lineno, 7) @test_utils.require_version(minver="3.8") def test_assign_after_posonly_param(self): """When an assignment statement overwrites a function positional-only parameter, only the assignment is returned, even when the variable and assignment do not have the same parent. """ code = """ def f1(x, /): x = 100 print(x) def f2(x, /): x = 100 if True: print(x) """ astroid = builder.parse(code) x_name1, x_name2 = ( n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x" ) _, stmts1 = x_name1.lookup("x") self.assertEqual(len(stmts1), 1) self.assertEqual(stmts1[0].lineno, 3) _, stmts2 = x_name2.lookup("x") self.assertEqual(len(stmts2), 1) self.assertEqual(stmts2[0].lineno, 7) def test_assign_after_args_param(self) -> None: """When an assignment statement overwrites a function parameter, only the assignment is returned. """ code = """ def f(*args, **kwargs): args = [100] kwargs = {} if True: print(args, kwargs) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "args"][0] _, stmts1 = x_name.lookup("args") self.assertEqual(len(stmts1), 1) self.assertEqual(stmts1[0].lineno, 3) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "kwargs"][ 0 ] _, stmts2 = x_name.lookup("kwargs") self.assertEqual(len(stmts2), 1) self.assertEqual(stmts2[0].lineno, 4) def test_except_var_in_block(self) -> None: """When the variable bound to an exception in an except clause, it is returned when that variable is used inside the except block. """ code = """ try: 1 / 0 except ZeroDivisionError as e: print(e) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "e"][0] _, stmts = x_name.lookup("e") self.assertEqual(len(stmts), 1) self.assertEqual(stmts[0].lineno, 4) def test_except_var_in_block_overwrites(self) -> None: """When the variable bound to an exception in an except clause, it is returned when that variable is used inside the except block, and replaces any previous assignments. """ code = """ e = 0 try: 1 / 0 except ZeroDivisionError as e: print(e) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "e"][0] _, stmts = x_name.lookup("e") self.assertEqual(len(stmts), 1) self.assertEqual(stmts[0].lineno, 5) def test_except_var_in_multiple_blocks(self) -> None: """When multiple variables with the same name are bound to an exception in an except clause, and the variable is used inside the except block, only the assignment from the corresponding except clause is returned. """ code = """ e = 0 try: 1 / 0 except ZeroDivisionError as e: print(e) except NameError as e: print(e) """ astroid = builder.parse(code) x_names = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "e"] _, stmts1 = x_names[0].lookup("e") self.assertEqual(len(stmts1), 1) self.assertEqual(stmts1[0].lineno, 5) _, stmts2 = x_names[1].lookup("e") self.assertEqual(len(stmts2), 1) self.assertEqual(stmts2[0].lineno, 7) def test_except_var_after_block_single(self) -> None: """When the variable bound to an exception in an except clause, it is NOT returned when that variable is used after the except block. """ code = """ try: 1 / 0 except NameError as e: pass print(e) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "e"][0] _, stmts = x_name.lookup("e") self.assertEqual(len(stmts), 0) def test_except_var_after_block_multiple(self) -> None: """When the variable bound to an exception in multiple except clauses, it is NOT returned when that variable is used after the except blocks. """ code = """ try: 1 / 0 except NameError as e: pass except ZeroDivisionError as e: pass print(e) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "e"][0] _, stmts = x_name.lookup("e") self.assertEqual(len(stmts), 0) def test_except_assign_in_block(self) -> None: """When a variable is assigned in an except block, it is returned when that variable is used in the except block. """ code = """ try: 1 / 0 except ZeroDivisionError as e: x = 10 print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 1) self.assertEqual(stmts[0].lineno, 5) def test_except_assign_in_block_multiple(self) -> None: """When a variable is assigned in multiple except blocks, and the variable is used in one of the blocks, only the assignments in that block are returned. """ code = """ try: 1 / 0 except ZeroDivisionError: x = 10 except NameError: x = 100 print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 1) self.assertEqual(stmts[0].lineno, 7) def test_except_assign_after_block(self) -> None: """When a variable is assigned in an except clause, it is returned when that variable is used after the except block. """ code = """ try: 1 / 0 except ZeroDivisionError: x = 10 except NameError: x = 100 print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 2) self.assertCountEqual([stmt.lineno for stmt in stmts], [5, 7]) def test_except_assign_after_block_overwritten(self) -> None: """When a variable is assigned in an except clause, it is not returned when it is reassigned and used after the except block. """ code = """ try: 1 / 0 except ZeroDivisionError: x = 10 except NameError: x = 100 x = 1000 print(x) """ astroid = builder.parse(code) x_name = [n for n in astroid.nodes_of_class(nodes.Name) if n.name == "x"][0] _, stmts = x_name.lookup("x") self.assertEqual(len(stmts), 1) self.assertEqual(stmts[0].lineno, 8) if __name__ == "__main__": unittest.main()