#10535: Enable silenced warnings in unittest by default

4 files changed, 160 insertions, 3 deletions

diff --git a/Lib/unittest/test/_test_warnings.py b/Lib/unittest/test/_test_warnings.py
new file mode 100644
index 0000000..d0be18d
--- /dev/null
+++ b/Lib/unittest/test/_test_warnings.py
@@ -0,0 +1,74 @@
+# helper module for test_runner.Test_TextTestRunner.test_warnings
+
+"""
+This module has a number of tests that raise different kinds of warnings.
+When the tests are run, the warnings are caught and their messages are printed
+to stdout.  This module also accepts an arg that is then passed to
+unittest.main to affect the behavior of warnings.
+Test_TextTestRunner.test_warnings executes this script with different
+combinations of warnings args and -W flags and check that the output is correct.
+See #10535.
+"""
+
+import io
+import sys
+import unittest
+import warnings
+
+def warnfun():
+    warnings.warn('rw', RuntimeWarning)
+
+class TestWarnings(unittest.TestCase):
+    # unittest warnings will be printed at most once per type (max one message
+    # for the fail* methods, and one for the assert* methods)
+    def test_assert(self):
+        self.assertEquals(2+2, 4)
+        self.assertEquals(2*2, 4)
+        self.assertEquals(2**2, 4)
+
+    def test_fail(self):
+        self.failUnless(1)
+        self.failUnless(True)
+
+    def test_other_unittest(self):
+        self.assertAlmostEqual(2+2, 4)
+        self.assertNotAlmostEqual(4+4, 2)
+
+    # these warnings are normally silenced, but they are printed in unittest
+    def test_deprecation(self):
+        warnings.warn('dw', DeprecationWarning)
+        warnings.warn('dw', DeprecationWarning)
+        warnings.warn('dw', DeprecationWarning)
+
+    def test_import(self):
+        warnings.warn('iw', ImportWarning)
+        warnings.warn('iw', ImportWarning)
+        warnings.warn('iw', ImportWarning)
+
+    # user warnings should always be printed
+    def test_warning(self):
+        warnings.warn('uw')
+        warnings.warn('uw')
+        warnings.warn('uw')
+
+    # these warnings come from the same place; they will be printed
+    # only once by default or three times if the 'always' filter is used
+    def test_function(self):
+
+        warnfun()
+        warnfun()
+        warnfun()
+
+
+
+if __name__ == '__main__':
+    with warnings.catch_warnings(record=True) as ws:
+        # if an arg is provided pass it to unittest.main as 'warnings'
+        if len(sys.argv) == 2:
+            unittest.main(exit=False, warnings=sys.argv.pop())
+        else:
+            unittest.main(exit=False)
+
+    # print all the warning messages collected
+    for w in ws:
+        print(w.message)
diff --git a/Lib/unittest/test/test_break.py b/Lib/unittest/test/test_break.py
index 0e09dfb..77ce201 100644
--- a/Lib/unittest/test/test_break.py
+++ b/Lib/unittest/test/test_break.py
@@ -209,7 +209,8 @@ class TestBreak(unittest.TestCase):
 
         self.assertEqual(FakeRunner.initArgs, [((), {'buffer': None,
                                                      'verbosity': verbosity,
-                                                     'failfast': failfast})])
+                                                     'failfast': failfast,
+                                                     'warnings': None})])
         self.assertEqual(FakeRunner.runArgs, [test])
         self.assertEqual(p.result, result)
 
@@ -222,7 +223,8 @@ class TestBreak(unittest.TestCase):
 
         self.assertEqual(FakeRunner.initArgs, [((), {'buffer': None,
                                                      'verbosity': verbosity,
-                                                     'failfast': failfast})])
+                                                     'failfast': failfast,
+                                                     'warnings': None})])
         self.assertEqual(FakeRunner.runArgs, [test])
         self.assertEqual(p.result, result)
 
diff --git a/Lib/unittest/test/test_program.py b/Lib/unittest/test/test_program.py
index f8e2804..2eb0be3 100644
--- a/Lib/unittest/test/test_program.py
+++ b/Lib/unittest/test/test_program.py
@@ -182,6 +182,27 @@ class TestCommandLineArgs(unittest.TestCase):
                 program.parseArgs([None, opt])
                 self.assertEqual(getattr(program, attr), not_none)
 
+    def testWarning(self):
+        """Test the warnings argument"""
+        # see #10535
+        class FakeTP(unittest.TestProgram):
+            def parseArgs(self, *args, **kw): pass
+            def runTests(self, *args, **kw): pass
+        warnoptions = sys.warnoptions
+        try:
+            sys.warnoptions[:] = []
+            # no warn options, no arg -> default
+            self.assertEqual(FakeTP().warnings, 'default')
+            # no warn options, w/ arg -> arg value
+            self.assertEqual(FakeTP(warnings='ignore').warnings, 'ignore')
+            sys.warnoptions[:] = ['somevalue']
+            # warn options, no arg -> None
+            # warn options, w/ arg -> arg value
+            self.assertEqual(FakeTP().warnings, None)
+            self.assertEqual(FakeTP(warnings='ignore').warnings, 'ignore')
+        finally:
+            sys.warnoptions[:] = warnoptions
+
     def testRunTestsRunnerClass(self):
         program = self.program
 
@@ -189,12 +210,14 @@ class TestCommandLineArgs(unittest.TestCase):
         program.verbosity = 'verbosity'
         program.failfast = 'failfast'
         program.buffer = 'buffer'
+        program.warnings = 'warnings'
 
         program.runTests()
 
         self.assertEqual(FakeRunner.initArgs, {'verbosity': 'verbosity',
                                                 'failfast': 'failfast',
-                                                'buffer': 'buffer'})
+                                                'buffer': 'buffer',
+                                                'warnings': 'warnings'})
         self.assertEqual(FakeRunner.test, 'test')
         self.assertIs(program.result, RESULT)
 
diff --git a/Lib/unittest/test/test_runner.py b/Lib/unittest/test/test_runner.py
index 25f7541..efd4962 100644
--- a/Lib/unittest/test/test_runner.py
+++ b/Lib/unittest/test/test_runner.py
@@ -1,5 +1,8 @@
 import io
+import os
+import sys
 import pickle
+import subprocess
 
 import unittest
 
@@ -144,6 +147,7 @@ class Test_TextTestRunner(unittest.TestCase):
         self.assertFalse(runner.failfast)
         self.assertFalse(runner.buffer)
         self.assertEqual(runner.verbosity, 1)
+        self.assertEqual(runner.warnings, None)
         self.assertTrue(runner.descriptions)
         self.assertEqual(runner.resultclass, unittest.TextTestResult)
 
@@ -244,3 +248,57 @@ class Test_TextTestRunner(unittest.TestCase):
 
         expectedresult = (runner.stream, DESCRIPTIONS, VERBOSITY)
         self.assertEqual(runner._makeResult(), expectedresult)
+
+    def test_warnings(self):
+        """
+        Check that warnings argument of TextTestRunner correctly affects the
+        behavior of the warnings.
+        """
+        # see #10535 and the _test_warnings file for more information
+
+        def get_parse_out_err(p):
+            return [b.splitlines() for b in p.communicate()]
+        opts = dict(stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                    cwd=os.path.dirname(__file__))
+        ae_msg = b'Please use assertEqual instead.'
+        at_msg = b'Please use assertTrue instead.'
+
+        # no args -> all the warnings are printed, unittest warnings only once
+        p = subprocess.Popen([sys.executable, '_test_warnings.py'], **opts)
+        out, err = get_parse_out_err(p)
+        self.assertEqual(err[-1], b'OK')
+        # check that the total number of warnings in the output is correct
+        self.assertEqual(len(out), 12)
+        # check that the numbers of the different kind of warnings is correct
+        for msg in [b'dw', b'iw', b'uw']:
+            self.assertEqual(out.count(msg), 3)
+        for msg in [ae_msg, at_msg, b'rw']:
+            self.assertEqual(out.count(msg), 1)
+
+        args_list = (
+            # passing 'ignore' as warnings arg -> no warnings
+            [sys.executable, '_test_warnings.py', 'ignore'],
+            # -W doesn't affect the result if the arg is passed
+            [sys.executable, '-Wa', '_test_warnings.py', 'ignore'],
+            # -W affects the result if the arg is not passed
+            [sys.executable, '-Wi', '_test_warnings.py']
+        )
+        # in all these cases no warnings are printed
+        for args in args_list:
+            p = subprocess.Popen(args, **opts)
+            out, err = get_parse_out_err(p)
+            self.assertEqual(err[-1], b'OK')
+            self.assertEqual(len(out), 0)
+
+
+        # passing 'always' as warnings arg -> all the warnings printed,
+        #                                     unittest warnings only once
+        p = subprocess.Popen([sys.executable, '_test_warnings.py', 'always'],
+                             **opts)
+        out, err = get_parse_out_err(p)
+        self.assertEqual(err[-1], b'OK')
+        self.assertEqual(len(out), 14)
+        for msg in [b'dw', b'iw', b'uw', b'rw']:
+            self.assertEqual(out.count(msg), 3)
+        for msg in [ae_msg, at_msg]:
+            self.assertEqual(out.count(msg), 1)