~bzr-pqm/bzr/bzr.dev

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
# Copyright (C) 2004, 2005, 2006 Canonical Ltd
#       Author: Robert Collins <robert.collins@canonical.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#

import sys
import logging
import unittest

# Mark this python module as being part of the implementation
# of unittest: this gives us better tracebacks where the last
# shown frame is the test code, not our assertXYZ.
__unittest = 1


class LogCollector(logging.Handler):
    def __init__(self):
        logging.Handler.__init__(self)
        self.records=[]
    def emit(self, record):
        self.records.append(record.getMessage())


def makeCollectingLogger():
    """I make a logger instance that collects its logs for programmatic analysis
    -> (logger, collector)"""
    logger=logging.Logger("collector")
    handler=LogCollector()
    handler.setFormatter(logging.Formatter("%(levelname)s: %(message)s"))
    logger.addHandler(handler)
    return logger, handler


def visitTests(suite, visitor):
    """A foreign method for visiting the tests in a test suite."""
    for test in suite._tests:
        #Abusing types to avoid monkey patching unittest.TestCase. 
        # Maybe that would be better?
        try:
            test.visit(visitor)
        except AttributeError:
            if isinstance(test, unittest.TestCase):
                visitor.visitCase(test)
            elif isinstance(test, unittest.TestSuite):
                visitor.visitSuite(test)
                visitTests(test, visitor)
            else:
                print "unvisitable non-unittest.TestCase element %r (%r)" % (test, test.__class__)
    

class TestSuite(unittest.TestSuite):
    """I am an extended TestSuite with a visitor interface.
    This is primarily to allow filtering of tests - and suites or
    more in the future. An iterator of just tests wouldn't scale..."""

    def visit(self, visitor):
        """visit the composite. Visiting is depth-first.
        current callbacks are visitSuite and visitCase."""
        visitor.visitSuite(self)
        visitTests(self, visitor)


class TestLoader(unittest.TestLoader):
    """Custom TestLoader to extend the stock python one."""

    suiteClass = TestSuite

    def loadTestsFromModuleNames(self, names):
        """use a custom means to load tests from modules.

        There is an undesirable glitch in the python TestLoader where a 
        import error is ignore. We think this can be solved by ensuring the 
        requested name is resolvable, if its not raising the original error.
        """
        result = self.suiteClass()
        for name in names:
            module = _load_module_by_name(name)
            result.addTests(self.loadTestsFromModule(module))
        return result

    def loadTestsFromModule(self, module):
        """Load tests from a module object.

        This extension of the python test loader looks for an attribute
        load_tests in the module object, and if not found falls back to the
        regular python loadTestsFromModule.

        If a load_tests attribute is found, it is called and the result is
        returned. 

        load_tests should be defined like so:
        >>> def load_tests(standard_tests, module, loader):
        >>>    pass

        standard_tests is the tests found by the stock TestLoader in the
        module, module and loader are the module and loader instances.

        For instance, to run every test twice, you might do:
        >>> def load_tests(standard_tests, module, loader):
        >>>     result = loader.suiteClass()
        >>>     for test in iter_suite_tests(standard_tests):
        >>>         result.addTests([test, test])
        >>>     return result
        """
        basic_tests = super(TestLoader, self).loadTestsFromModule(module)
        load_tests = getattr(module, "load_tests", None)
        if load_tests is not None:
            return load_tests(basic_tests, module, self)
        else:
            return basic_tests


def _load_module_by_name(mod_name):
    parts = mod_name.split('.')
    module = __import__(mod_name)
    del parts[0]
    # for historical reasons python returns the top-level module even though
    # it loads the submodule; we need to walk down to get the one we want.
    while parts:
        module = getattr(module, parts.pop(0))
    return module


class TestVisitor(object):
    """A visitor for Tests"""
    def visitSuite(self, aTestSuite):
        pass
    def visitCase(self, aTestCase):
        pass