summaryrefslogtreecommitdiffstats
path: root/Lib/test/test_importhooks.py
blob: 2a22d1a186c9d7cdb910d32384e30192c8b7fbca (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
import sys
import imp
import os
import unittest
from test import support


test_src = """\
def get_name():
    return __name__
def get_file():
    return __file__
"""

absimp = "import sub\n"
relimp = "from . import sub\n"
deeprelimp = "from .... import sub\n"
futimp = "from __future__ import absolute_import\n"

reload_src = test_src+"""\
reloaded = True
"""

test_co = compile(test_src, "<???>", "exec")
reload_co = compile(reload_src, "<???>", "exec")

test2_oldabs_co = compile(absimp + test_src, "<???>", "exec")
test2_newabs_co = compile(futimp + absimp + test_src, "<???>", "exec")
test2_newrel_co = compile(relimp + test_src, "<???>", "exec")
test2_deeprel_co = compile(deeprelimp + test_src, "<???>", "exec")
test2_futrel_co = compile(futimp + relimp + test_src, "<???>", "exec")

test_path = "!!!_test_!!!"


class TestImporter:

    modules = {
        "hooktestmodule": (False, test_co),
        "hooktestpackage": (True, test_co),
        "hooktestpackage.sub": (True, test_co),
        "hooktestpackage.sub.subber": (True, test_co),
        "hooktestpackage.oldabs": (False, test2_oldabs_co),
        "hooktestpackage.newabs": (False, test2_newabs_co),
        "hooktestpackage.newrel": (False, test2_newrel_co),
        "hooktestpackage.sub.subber.subest": (True, test2_deeprel_co),
        "hooktestpackage.futrel": (False, test2_futrel_co),
        "sub": (False, test_co),
        "reloadmodule": (False, test_co),
    }

    def __init__(self, path=test_path):
        if path != test_path:
            # if our class is on sys.path_hooks, we must raise
            # ImportError for any path item that we can't handle.
            raise ImportError
        self.path = path

    def _get__path__(self):
        raise NotImplementedError

    def find_module(self, fullname, path=None):
        if fullname in self.modules:
            return self
        else:
            return None

    def load_module(self, fullname):
        ispkg, code = self.modules[fullname]
        mod = sys.modules.setdefault(fullname,imp.new_module(fullname))
        mod.__file__ = "<%s>" % self.__class__.__name__
        mod.__loader__ = self
        if ispkg:
            mod.__path__ = self._get__path__()
        exec(code, mod.__dict__)
        return mod


class MetaImporter(TestImporter):
    def _get__path__(self):
        return []

class PathImporter(TestImporter):
    def _get__path__(self):
        return [self.path]


class ImportBlocker:
    """Place an ImportBlocker instance on sys.meta_path and you
    can be sure the modules you specified can't be imported, even
    if it's a builtin."""
    def __init__(self, *namestoblock):
        self.namestoblock = dict.fromkeys(namestoblock)
    def find_module(self, fullname, path=None):
        if fullname in self.namestoblock:
            return self
        return None
    def load_module(self, fullname):
        raise ImportError("I dare you")


class ImpWrapper:

    def __init__(self, path=None):
        if path is not None and not os.path.isdir(path):
            raise ImportError
        self.path = path

    def find_module(self, fullname, path=None):
        subname = fullname.split(".")[-1]
        if subname != fullname and self.path is None:
            return None
        if self.path is None:
            path = None
        else:
            path = [self.path]
        try:
            file, filename, stuff = imp.find_module(subname, path)
        except ImportError:
            return None
        return ImpLoader(file, filename, stuff)


class ImpLoader:

    def __init__(self, file, filename, stuff):
        self.file = file
        self.filename = filename
        self.stuff = stuff

    def load_module(self, fullname):
        mod = imp.load_module(fullname, self.file, self.filename, self.stuff)
        if self.file:
            self.file.close()
        mod.__loader__ = self  # for introspection
        return mod


class ImportHooksBaseTestCase(unittest.TestCase):

    def setUp(self):
        self.path = sys.path[:]
        self.meta_path = sys.meta_path[:]
        self.path_hooks = sys.path_hooks[:]
        sys.path_importer_cache.clear()
        self.modules_before = support.modules_setup()

    def tearDown(self):
        sys.path[:] = self.path
        sys.meta_path[:] = self.meta_path
        sys.path_hooks[:] = self.path_hooks
        sys.path_importer_cache.clear()
        support.modules_cleanup(*self.modules_before)


class ImportHooksTestCase(ImportHooksBaseTestCase):

    def doTestImports(self, importer=None):
        import hooktestmodule
        import hooktestpackage
        import hooktestpackage.sub
        import hooktestpackage.sub.subber
        self.assertEqual(hooktestmodule.get_name(),
                         "hooktestmodule")
        self.assertEqual(hooktestpackage.get_name(),
                         "hooktestpackage")
        self.assertEqual(hooktestpackage.sub.get_name(),
                         "hooktestpackage.sub")
        self.assertEqual(hooktestpackage.sub.subber.get_name(),
                         "hooktestpackage.sub.subber")
        if importer:
            self.assertEqual(hooktestmodule.__loader__, importer)
            self.assertEqual(hooktestpackage.__loader__, importer)
            self.assertEqual(hooktestpackage.sub.__loader__, importer)
            self.assertEqual(hooktestpackage.sub.subber.__loader__, importer)

        TestImporter.modules['reloadmodule'] = (False, test_co)
        import reloadmodule
        self.assertFalse(hasattr(reloadmodule,'reloaded'))

        import hooktestpackage.newrel
        self.assertEqual(hooktestpackage.newrel.get_name(),
                         "hooktestpackage.newrel")
        self.assertEqual(hooktestpackage.newrel.sub,
                         hooktestpackage.sub)

        import hooktestpackage.sub.subber.subest as subest
        self.assertEqual(subest.get_name(),
                         "hooktestpackage.sub.subber.subest")
        self.assertEqual(subest.sub,
                         hooktestpackage.sub)

        import hooktestpackage.futrel
        self.assertEqual(hooktestpackage.futrel.get_name(),
                         "hooktestpackage.futrel")
        self.assertEqual(hooktestpackage.futrel.sub,
                         hooktestpackage.sub)

        import sub
        self.assertEqual(sub.get_name(), "sub")

        import hooktestpackage.oldabs
        self.assertEqual(hooktestpackage.oldabs.get_name(),
                         "hooktestpackage.oldabs")
        self.assertEqual(hooktestpackage.oldabs.sub, sub)

        import hooktestpackage.newabs
        self.assertEqual(hooktestpackage.newabs.get_name(),
                         "hooktestpackage.newabs")
        self.assertEqual(hooktestpackage.newabs.sub, sub)

    def testMetaPath(self):
        i = MetaImporter()
        sys.meta_path.append(i)
        self.doTestImports(i)

    def testPathHook(self):
        sys.path_hooks.insert(0, PathImporter)
        sys.path.append(test_path)
        self.doTestImports()

    def testBlocker(self):
        mname = "exceptions"  # an arbitrary harmless builtin module
        support.unload(mname)
        sys.meta_path.append(ImportBlocker(mname))
        self.assertRaises(ImportError, __import__, mname)

    def testImpWrapper(self):
        i = ImpWrapper()
        sys.meta_path.append(i)
        sys.path_hooks.insert(0, ImpWrapper)
        mnames = (
            "colorsys", "urllib.parse", "distutils.core", "sys",
        )
        for mname in mnames:
            parent = mname.split(".")[0]
            for n in list(sys.modules):
                if n.startswith(parent):
                    del sys.modules[n]
        for mname in mnames:
            m = __import__(mname, globals(), locals(), ["__dummy__"])
            # to make sure we actually handled the import
            self.assertTrue(hasattr(m, "__loader__"))


def test_main():
    support.run_unittest(ImportHooksTestCase)

if __name__ == "__main__":
    test_main()