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Viewing changes to bzrlib/tests/test_lazy_import.py

  • Committer: John Arbash Meinel
  • Date: 2006-09-12 17:33:23 UTC
  • mto: This revision was merged to the branch mainline in revision 2004.
  • Revision ID: john@arbash-meinel.com-20060912173323-112d28652516fd94
Raise an exception when ScopeReplacer has been misused

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bzrlib/tests/test_lazy_import.py
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import sys
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from bzrlib import (
 
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    errors,
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    lazy_import,
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    osutils,
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    )
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                          'func',
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                         ], actions)
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    def test_other_variable(self):
 
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        """Test when a ScopeReplacer is assigned to another variable.
 
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        This test could be updated if we find a way to trap '=' rather
 
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        than just giving a belated exception.
 
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        ScopeReplacer only knows about the variable it was created as,
 
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        so until the object is replaced, it is illegal to pass it to
 
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        another variable. (Though discovering this may take a while)
 
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        """
 
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        actions = []
 
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        InstrumentedReplacer.use_actions(actions)
 
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        TestClass.use_actions(actions)
 
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        def factory(replacer, scope, name):
 
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            actions.append('factory')
 
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            return TestClass()
 
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        try:
 
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            test_obj2
 
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        except NameError:
 
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            # test_obj2 shouldn't exist yet
 
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            pass
 
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        else:
 
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            self.fail('test_obj2 was not supposed to exist yet')
 
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        InstrumentedReplacer(scope=globals(), name='test_obj2',
 
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                             factory=factory)
 
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        self.assertEqual(InstrumentedReplacer,
 
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                         object.__getattribute__(test_obj2, '__class__'))
 
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        # This is technically not allowed, but we don't have a way to
 
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        # test it until later.
 
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        test_obj3 = test_obj2
 
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        self.assertEqual(InstrumentedReplacer,
 
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                         object.__getattribute__(test_obj2, '__class__'))
 
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        self.assertEqual(InstrumentedReplacer,
 
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                         object.__getattribute__(test_obj3, '__class__'))
 
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        # The first use of the alternate variable causes test_obj2 to
 
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        # be replaced.
 
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        self.assertEqual('foo', test_obj3.foo(1))
 
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        # test_obj2 has been replaced, but the ScopeReplacer has no
 
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        # idea of test_obj3
 
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        self.assertEqual(TestClass,
 
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                         object.__getattribute__(test_obj2, '__class__'))
 
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        self.assertEqual(InstrumentedReplacer,
 
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                         object.__getattribute__(test_obj3, '__class__'))
 
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        # We should be able to access test_obj2 attributes normally
 
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        self.assertEqual('foo', test_obj2.foo(2))
 
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        self.assertEqual('foo', test_obj2.foo(3))
 
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        # However, the next access on test_obj3 should raise an error
 
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        # because only now are we able to detect the problem.
 
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        self.assertRaises(errors.IllegalUseOfScopeReplacer,
 
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                          getattr, test_obj3, 'foo')
 
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        # However, the 
 
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        self.assertEqual([('__getattribute__', 'foo'),
 
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                          '_replace',
 
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                          'factory',
 
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                          'init',
 
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                          ('foo', 1),
 
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                          ('foo', 2),
 
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                          ('foo', 3),
 
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                          ('__getattribute__', 'foo'),
 
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                          '_replace',
 
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                         ], actions)
 
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class ImportReplacerHelper(TestCaseInTempDir):
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    """Test the ability to have a lazily imported module or object"""