test_resources.py 文件源码

def testResolve(self):
        ad = pkg_resources.Environment([])
        ws = WorkingSet([])
        # Resolving no requirements -> nothing to install
        self.assertEqual(list(ws.resolve([],ad)), [])
        # Request something not in the collection -> DistributionNotFound
        self.assertRaises(
            pkg_resources.DistributionNotFound, ws.resolve, parse_requirements("Foo"), ad
        )
        Foo = Distribution.from_filename(
            "/foo_dir/Foo-1.2.egg",
            metadata=Metadata(('depends.txt', "[bar]\nBaz>=2.0"))
        )
        ad.add(Foo)
        ad.add(Distribution.from_filename("Foo-0.9.egg"))

        # Request thing(s) that are available -> list to activate
        for i in range(3):
            targets = list(ws.resolve(parse_requirements("Foo"), ad))
            self.assertEqual(targets, [Foo])
            list(map(ws.add,targets))
        self.assertRaises(VersionConflict, ws.resolve,
            parse_requirements("Foo==0.9"), ad)
        ws = WorkingSet([]) # reset

        # Request an extra that causes an unresolved dependency for "Baz"
        self.assertRaises(
            pkg_resources.DistributionNotFound, ws.resolve,parse_requirements("Foo[bar]"), ad
        )
        Baz = Distribution.from_filename(
            "/foo_dir/Baz-2.1.egg", metadata=Metadata(('depends.txt', "Foo"))
        )
        ad.add(Baz)

        # Activation list now includes resolved dependency
        self.assertEqual(
            list(ws.resolve(parse_requirements("Foo[bar]"), ad)), [Foo,Baz]
        )
        # Requests for conflicting versions produce VersionConflict
        self.assertRaises(VersionConflict,
            ws.resolve, parse_requirements("Foo==1.2\nFoo!=1.2"), ad)