Source

python-clinic / Lib / test / test_importlib / source / test_abc_loader.py

  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
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
import importlib
from importlib import abc

from .. import abc as testing_abc
from .. import util
from . import util as source_util

import imp
import inspect
import io
import marshal
import os
import sys
import types
import unittest
import warnings


class SourceOnlyLoaderMock(abc.SourceLoader):

    # Globals that should be defined for all modules.
    source = (b"_ = '::'.join([__name__, __file__, __cached__, __package__, "
              b"repr(__loader__)])")

    def __init__(self, path):
        self.path = path

    def get_data(self, path):
        assert self.path == path
        return self.source

    def get_filename(self, fullname):
        return self.path

    def module_repr(self, module):
        return '<module>'


class SourceLoaderMock(SourceOnlyLoaderMock):

    source_mtime = 1

    def __init__(self, path, magic=imp.get_magic()):
        super().__init__(path)
        self.bytecode_path = imp.cache_from_source(self.path)
        self.source_size = len(self.source)
        data = bytearray(magic)
        data.extend(importlib._w_long(self.source_mtime))
        data.extend(importlib._w_long(self.source_size))
        code_object = compile(self.source, self.path, 'exec',
                                dont_inherit=True)
        data.extend(marshal.dumps(code_object))
        self.bytecode = bytes(data)
        self.written = {}

    def get_data(self, path):
        if path == self.path:
            return super().get_data(path)
        elif path == self.bytecode_path:
            return self.bytecode
        else:
            raise OSError

    def path_stats(self, path):
        assert path == self.path
        return {'mtime': self.source_mtime, 'size': self.source_size}

    def set_data(self, path, data):
        self.written[path] = bytes(data)
        return path == self.bytecode_path


def raise_ImportError(*args, **kwargs):
    raise ImportError


class SourceLoaderTestHarness(unittest.TestCase):

    def setUp(self, *, is_package=True, **kwargs):
        self.package = 'pkg'
        if is_package:
            self.path = os.path.join(self.package, '__init__.py')
            self.name = self.package
        else:
            module_name = 'mod'
            self.path = os.path.join(self.package, '.'.join(['mod', 'py']))
            self.name = '.'.join([self.package, module_name])
        self.cached = imp.cache_from_source(self.path)
        self.loader = self.loader_mock(self.path, **kwargs)

    def verify_module(self, module):
        self.assertEqual(module.__name__, self.name)
        self.assertEqual(module.__file__, self.path)
        self.assertEqual(module.__cached__, self.cached)
        self.assertEqual(module.__package__, self.package)
        self.assertEqual(module.__loader__, self.loader)
        values = module._.split('::')
        self.assertEqual(values[0], self.name)
        self.assertEqual(values[1], self.path)
        self.assertEqual(values[2], self.cached)
        self.assertEqual(values[3], self.package)
        self.assertEqual(values[4], repr(self.loader))

    def verify_code(self, code_object):
        module = imp.new_module(self.name)
        module.__file__ = self.path
        module.__cached__ = self.cached
        module.__package__ = self.package
        module.__loader__ = self.loader
        module.__path__ = []
        exec(code_object, module.__dict__)
        self.verify_module(module)


class SourceOnlyLoaderTests(SourceLoaderTestHarness):

    """Test importlib.abc.SourceLoader for source-only loading.

    Reload testing is subsumed by the tests for
    importlib.util.module_for_loader.

    """

    loader_mock = SourceOnlyLoaderMock

    def test_get_source(self):
        # Verify the source code is returned as a string.
        # If an OSError is raised by get_data then raise ImportError.
        expected_source = self.loader.source.decode('utf-8')
        self.assertEqual(self.loader.get_source(self.name), expected_source)
        def raise_OSError(path):
            raise OSError
        self.loader.get_data = raise_OSError
        with self.assertRaises(ImportError) as cm:
            self.loader.get_source(self.name)
        self.assertEqual(cm.exception.name, self.name)

    def test_is_package(self):
        # Properly detect when loading a package.
        self.setUp(is_package=False)
        self.assertFalse(self.loader.is_package(self.name))
        self.setUp(is_package=True)
        self.assertTrue(self.loader.is_package(self.name))
        self.assertFalse(self.loader.is_package(self.name + '.__init__'))

    def test_get_code(self):
        # Verify the code object is created.
        code_object = self.loader.get_code(self.name)
        self.verify_code(code_object)

    def test_source_to_code(self):
        # Verify the compiled code object.
        code = self.loader.source_to_code(self.loader.source, self.path)
        self.verify_code(code)

    def test_load_module(self):
        # Loading a module should set __name__, __loader__, __package__,
        # __path__ (for packages), __file__, and __cached__.
        # The module should also be put into sys.modules.
        with util.uncache(self.name):
            module = self.loader.load_module(self.name)
            self.verify_module(module)
            self.assertEqual(module.__path__, [os.path.dirname(self.path)])
            self.assertIn(self.name, sys.modules)

    def test_package_settings(self):
        # __package__ needs to be set, while __path__ is set on if the module
        # is a package.
        # Testing the values for a package are covered by test_load_module.
        self.setUp(is_package=False)
        with util.uncache(self.name):
            module = self.loader.load_module(self.name)
            self.verify_module(module)
            self.assertTrue(not hasattr(module, '__path__'))

    def test_get_source_encoding(self):
        # Source is considered encoded in UTF-8 by default unless otherwise
        # specified by an encoding line.
        source = "_ = 'ü'"
        self.loader.source = source.encode('utf-8')
        returned_source = self.loader.get_source(self.name)
        self.assertEqual(returned_source, source)
        source = "# coding: latin-1\n_ = ü"
        self.loader.source = source.encode('latin-1')
        returned_source = self.loader.get_source(self.name)
        self.assertEqual(returned_source, source)


@unittest.skipIf(sys.dont_write_bytecode, "sys.dont_write_bytecode is true")
class SourceLoaderBytecodeTests(SourceLoaderTestHarness):

    """Test importlib.abc.SourceLoader's use of bytecode.

    Source-only testing handled by SourceOnlyLoaderTests.

    """

    loader_mock = SourceLoaderMock

    def verify_code(self, code_object, *, bytecode_written=False):
        super().verify_code(code_object)
        if bytecode_written:
            self.assertIn(self.cached, self.loader.written)
            data = bytearray(imp.get_magic())
            data.extend(importlib._w_long(self.loader.source_mtime))
            data.extend(importlib._w_long(self.loader.source_size))
            data.extend(marshal.dumps(code_object))
            self.assertEqual(self.loader.written[self.cached], bytes(data))

    def test_code_with_everything(self):
        # When everything should work.
        code_object = self.loader.get_code(self.name)
        self.verify_code(code_object)

    def test_no_bytecode(self):
        # If no bytecode exists then move on to the source.
        self.loader.bytecode_path = "<does not exist>"
        # Sanity check
        with self.assertRaises(OSError):
            bytecode_path = imp.cache_from_source(self.path)
            self.loader.get_data(bytecode_path)
        code_object = self.loader.get_code(self.name)
        self.verify_code(code_object, bytecode_written=True)

    def test_code_bad_timestamp(self):
        # Bytecode is only used when the timestamp matches the source EXACTLY.
        for source_mtime in (0, 2):
            assert source_mtime != self.loader.source_mtime
            original = self.loader.source_mtime
            self.loader.source_mtime = source_mtime
            # If bytecode is used then EOFError would be raised by marshal.
            self.loader.bytecode = self.loader.bytecode[8:]
            code_object = self.loader.get_code(self.name)
            self.verify_code(code_object, bytecode_written=True)
            self.loader.source_mtime = original

    def test_code_bad_magic(self):
        # Skip over bytecode with a bad magic number.
        self.setUp(magic=b'0000')
        # If bytecode is used then EOFError would be raised by marshal.
        self.loader.bytecode = self.loader.bytecode[8:]
        code_object = self.loader.get_code(self.name)
        self.verify_code(code_object, bytecode_written=True)

    def test_dont_write_bytecode(self):
        # Bytecode is not written if sys.dont_write_bytecode is true.
        # Can assume it is false already thanks to the skipIf class decorator.
        try:
            sys.dont_write_bytecode = True
            self.loader.bytecode_path = "<does not exist>"
            code_object = self.loader.get_code(self.name)
            self.assertNotIn(self.cached, self.loader.written)
        finally:
            sys.dont_write_bytecode = False

    def test_no_set_data(self):
        # If set_data is not defined, one can still read bytecode.
        self.setUp(magic=b'0000')
        original_set_data = self.loader.__class__.set_data
        try:
            del self.loader.__class__.set_data
            code_object = self.loader.get_code(self.name)
            self.verify_code(code_object)
        finally:
            self.loader.__class__.set_data = original_set_data

    def test_set_data_raises_exceptions(self):
        # Raising NotImplementedError or OSError is okay for set_data.
        def raise_exception(exc):
            def closure(*args, **kwargs):
                raise exc
            return closure

        self.setUp(magic=b'0000')
        self.loader.set_data = raise_exception(NotImplementedError)
        code_object = self.loader.get_code(self.name)
        self.verify_code(code_object)


class SourceLoaderGetSourceTests(unittest.TestCase):

    """Tests for importlib.abc.SourceLoader.get_source()."""

    def test_default_encoding(self):
        # Should have no problems with UTF-8 text.
        name = 'mod'
        mock = SourceOnlyLoaderMock('mod.file')
        source = 'x = "ü"'
        mock.source = source.encode('utf-8')
        returned_source = mock.get_source(name)
        self.assertEqual(returned_source, source)

    def test_decoded_source(self):
        # Decoding should work.
        name = 'mod'
        mock = SourceOnlyLoaderMock("mod.file")
        source = "# coding: Latin-1\nx='ü'"
        assert source.encode('latin-1') != source.encode('utf-8')
        mock.source = source.encode('latin-1')
        returned_source = mock.get_source(name)
        self.assertEqual(returned_source, source)

    def test_universal_newlines(self):
        # PEP 302 says universal newlines should be used.
        name = 'mod'
        mock = SourceOnlyLoaderMock('mod.file')
        source = "x = 42\r\ny = -13\r\n"
        mock.source = source.encode('utf-8')
        expect = io.IncrementalNewlineDecoder(None, True).decode(source)
        self.assertEqual(mock.get_source(name), expect)


class AbstractMethodImplTests(unittest.TestCase):

    """Test the concrete abstractmethod implementations."""

    class MetaPathFinder(abc.MetaPathFinder):
        def find_module(self, fullname, path):
            super().find_module(fullname, path)

    class PathEntryFinder(abc.PathEntryFinder):
        def find_module(self, _):
            super().find_module(_)

        def find_loader(self, _):
            super().find_loader(_)

    class Finder(abc.Finder):
        def find_module(self, fullname, path):
            super().find_module(fullname, path)

    class Loader(abc.Loader):
        def load_module(self, fullname):
            super().load_module(fullname)

        def module_repr(self, module):
            super().module_repr(module)

    class ResourceLoader(Loader, abc.ResourceLoader):
        def get_data(self, _):
            super().get_data(_)

    class InspectLoader(Loader, abc.InspectLoader):
        def is_package(self, _):
            super().is_package(_)

        def get_code(self, _):
            super().get_code(_)

        def get_source(self, _):
            super().get_source(_)

    class ExecutionLoader(InspectLoader, abc.ExecutionLoader):
        def get_filename(self, _):
            super().get_filename(_)

    class SourceLoader(ResourceLoader, ExecutionLoader, abc.SourceLoader):
        pass

    def raises_NotImplementedError(self, ins, *args):
        for method_name in args:
            method = getattr(ins, method_name)
            arg_count = len(inspect.getfullargspec(method)[0]) - 1
            args = [''] * arg_count
            try:
                method(*args)
            except NotImplementedError:
                pass
            else:
                msg = "{}.{} did not raise NotImplementedError"
                self.fail(msg.format(ins.__class__.__name__, method_name))

    def test_Loader(self):
        self.raises_NotImplementedError(self.Loader(), 'load_module')

    # XXX misplaced; should be somewhere else
    def test_Finder(self):
        self.raises_NotImplementedError(self.Finder(), 'find_module')

    def test_ResourceLoader(self):
        self.raises_NotImplementedError(self.ResourceLoader(), 'load_module',
                                        'get_data')

    def test_InspectLoader(self):
        self.raises_NotImplementedError(self.InspectLoader(), 'load_module',
                                        'is_package', 'get_code', 'get_source')

    def test_ExecutionLoader(self):
        self.raises_NotImplementedError(self.ExecutionLoader(), 'load_module',
                                        'is_package', 'get_code', 'get_source',
                                        'get_filename')

    def test_SourceLoader(self):
        ins = self.SourceLoader()
        # Required abstractmethods.
        self.raises_NotImplementedError(ins, 'get_filename', 'get_data')
        # Optional abstractmethods.
        self.raises_NotImplementedError(ins, 'path_stats', 'set_data')


def test_main():
    from test.support import run_unittest
    run_unittest(SourceOnlyLoaderTests,
                 SourceLoaderBytecodeTests,
                 SourceLoaderGetSourceTests,
                 AbstractMethodImplTests)


if __name__ == '__main__':
    test_main()