Simplify/modernise tests for exceptions and warnings.

Use unicode.assertWarnsRegex() instead of "hand written"
warnings catching.

Use unicode.assertRaises() as context manager
(unless this would mean an additional code line).

git-svn-id: https://svn.code.sf.net/p/docutils/code/trunk@9011 929543f6-e4f2-0310-98a6-ba3bd3dd1d04

13 files changed, 83 insertions, 108 deletions

diff --git a/docutils/test/local-writer.py b/docutils/test/local-writer.py
index 891bb9273..4e0c19604 100644
--- a/docutils/test/local-writer.py
+++ b/docutils/test/local-writer.py
@@ -8,10 +8,6 @@ mini-writer to test get_writer_class with local writer
 
 import docutils
 from docutils import nodes, writers, languages
-try:
-    import roman
-except ImportError:
-    import docutils.utils.roman as roman
 
 class Writer(writers.Writer):
 
diff --git a/docutils/test/test_io.py b/docutils/test/test_io.py
index 7c21b4b24..8d3cc3f32 100755
--- a/docutils/test/test_io.py
+++ b/docutils/test/test_io.py
@@ -11,7 +11,6 @@ Test module for io.py.
 from io import StringIO, BytesIO
 import sys
 import unittest
-import warnings
 
 import DocutilsTestSupport              # must be imported before docutils
 from docutils import io
@@ -185,11 +184,9 @@ class OutputTests(unittest.TestCase):
         self.assertEqual(self.udrain.getvalue(), self.udata)
 
     def test_FileOutput_hande_io_errors_deprection_warning(self):
-        with warnings.catch_warnings(record=True) as wng:
-            warnings.simplefilter("always")
+        with self.assertWarnsRegex(DeprecationWarning,
+                                   '"handle_io_errors" is ignored'):
             fo = io.FileOutput(handle_io_errors=True)
-            self.assertEqual(len(wng), 1, "Expected a DeprecationWarning.")
-            assert issubclass(wng[0].category, DeprecationWarning)
 
     # With destination in binary mode, data must be binary string
     # and is written as-is:
diff --git a/docutils/test/test_nodes.py b/docutils/test/test_nodes.py
index 605ffa2d9..d1c9e998f 100755
--- a/docutils/test/test_nodes.py
+++ b/docutils/test/test_nodes.py
@@ -8,7 +8,6 @@ Test module for nodes.py.
 """
 
 import unittest
-import warnings
 
 import DocutilsTestSupport              # must be imported before docutils
 from DocutilsTestSupport import nodes, utils
@@ -67,11 +66,9 @@ class TextTests(unittest.TestCase):
                          r"<#text: 'Mary had a lit ...'>")
 
     def test_Text_rawsource_deprection_warning(self):
-        with warnings.catch_warnings(record=True) as wng:
-            warnings.simplefilter("always")
+        with self.assertWarnsRegex(DeprecationWarning,
+                                   '"rawsource" is ignored'):
             nodes.Text('content', rawsource='content')
-            self.assertEqual(len(wng), 1, "Expected a DeprecationWarning.")
-            assert issubclass(wng[-1].category, DeprecationWarning)
 
 
 class ElementTests(unittest.TestCase):
@@ -708,8 +705,8 @@ class NodeVisitorTests(unittest.TestCase):
 
     def test_dispatch_visit_unknown(self):
         # raise exception if no visit/depart methods are defined for node class
-        self.assertRaises(NotImplementedError,
-                          self.visitor.dispatch_visit, self.element)
+        with self.assertRaises(NotImplementedError):
+            self.visitor.dispatch_visit(self.element)
 
     def test_dispatch_visit_optional(self):
         # silently skip nodes of a calss in tuple nodes.NodeVisitor.optional
diff --git a/docutils/test/test_parsers/test_get_parser_class.py b/docutils/test/test_parsers/test_get_parser_class.py
index fec6a2bab..b1262cff5 100644
--- a/docutils/test/test_parsers/test_get_parser_class.py
+++ b/docutils/test/test_parsers/test_get_parser_class.py
@@ -21,8 +21,8 @@ class GetParserClassTestCase(DocutilsTestSupport.StandardTestCase):
         # raises ImportError on failure
 
     def test_bogus_parser(self):
-        self.assertRaises(ImportError,
-                          get_parser_class, 'nope')
+        with self.assertRaises(ImportError):
+            get_parser_class('nope')
 
     def test_local_parser(self):
         # requires local-parser.py in test directory (testroot)
diff --git a/docutils/test/test_parsers/test_recommonmark/test_misc.py b/docutils/test/test_parsers/test_recommonmark/test_misc.py
index 4c7052c7a..02e7ba490 100644
--- a/docutils/test/test_parsers/test_recommonmark/test_misc.py
+++ b/docutils/test/test_parsers/test_recommonmark/test_misc.py
@@ -72,13 +72,10 @@ class RecommonmarkParserTests(unittest.TestCase):
 class RecommonmarkMissingTests(unittest.TestCase):
 
     def test_missing_parser_message(self):
-        try:
-            output = publish_string(sample_with_html,
-                                    parser_name='recommonmark')
-        except ImportError as err:
-            self.assertIn(
-                'requires the package https://pypi.org/project/recommonmark',
-                str(err))
+        with self.assertRaisesRegex(ImportError,
+                                    'requires the package .*recommonmark'):
+            publish_string(sample_with_html, parser_name='recommonmark')
+
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/docutils/test/test_publisher.py b/docutils/test/test_publisher.py
index f00fc7344..c3fa0cc43 100755
--- a/docutils/test/test_publisher.py
+++ b/docutils/test/test_publisher.py
@@ -65,20 +65,16 @@ class PublisherTests(DocutilsTestSupport.StandardTestCase):
         # exits with a short message, if `traceback` is False,
 
         # pass IOErrors to calling application if `traceback` is True
-        try:
+        with self.assertRaises(IOError):
             core.publish_cmdline(argv=['nonexisting/path'],
                                  settings_overrides={'traceback': True})
-        except IOError as e:
-            self.assertTrue(isinstance(e, io.InputError))
 
 
     def test_output_error_handling(self):
         # pass IOErrors to calling application if `traceback` is True
-        try:
+        with self.assertRaises(io.OutputError):
             core.publish_cmdline(argv=['data/include.txt', 'nonexisting/path'],
                                  settings_overrides={'traceback': True})
-        except IOError as e:
-            self.assertTrue(isinstance(e, io.OutputError))
 
 
 class PublishDoctreeTestCase(DocutilsTestSupport.StandardTestCase, docutils.SettingsSpec):
diff --git a/docutils/test/test_readers/test_get_reader_class.py b/docutils/test/test_readers/test_get_reader_class.py
index 72eb4a20e..8c9566047 100644
--- a/docutils/test/test_readers/test_get_reader_class.py
+++ b/docutils/test/test_readers/test_get_reader_class.py
@@ -22,8 +22,8 @@ class GetReaderClassTestCase(DocutilsTestSupport.StandardTestCase):
         # raises ImportError on failure
 
     def test_bogus_reader(self):
-        self.assertRaises(ImportError,
-                          get_reader_class, 'nope')
+        with self.assertRaises(ImportError):
+            get_reader_class('nope')
 
     def test_local_reader(self):
         # requires local-reader.py in test directory (testroot)
diff --git a/docutils/test/test_statemachine.py b/docutils/test/test_statemachine.py
index 3532590a6..4e2a9b723 100755
--- a/docutils/test/test_statemachine.py
+++ b/docutils/test/test_statemachine.py
@@ -110,8 +110,8 @@ class EmptySMTests(unittest.TestCase):
     def test_add_state(self):
         self.sm.add_state(statemachine.State)
         self.assertTrue(len(self.sm.states) == 1)
-        self.assertRaises(statemachine.DuplicateStateError, self.sm.add_state,
-                          statemachine.State)
+        with self.assertRaises(statemachine.DuplicateStateError):
+            self.sm.add_state(statemachine.State)
         self.sm.add_state(statemachine.StateWS)
         self.assertTrue(len(self.sm.states) == 2)
 
@@ -122,8 +122,8 @@ class EmptySMTests(unittest.TestCase):
     def test_get_state(self):
         self.assertRaises(statemachine.UnknownStateError, self.sm.get_state)
         self.sm.add_states((statemachine.State, statemachine.StateWS))
-        self.assertRaises(statemachine.UnknownStateError, self.sm.get_state,
-                          'unknownState')
+        with self.assertRaises(statemachine.UnknownStateError):
+            self.sm.get_state('unknownState')
         self.assertTrue(isinstance(self.sm.get_state('State'),
                                    statemachine.State))
         self.assertTrue(isinstance(self.sm.get_state('StateWS'),
@@ -196,8 +196,8 @@ class SMWSTests(unittest.TestCase):
         textblock = self.sm.get_text_block(flush_left=1)
         self.assertEqual(textblock, testtext[:1])
         self.sm.next_line(2)
-        self.assertRaises(statemachine.UnexpectedIndentationError,
-                          self.sm.get_text_block, flush_left=1)
+        with self.assertRaises(statemachine.UnexpectedIndentationError):
+            self.sm.get_text_block(flush_left=1)
 
     def test_run(self):
         self.assertEqual(self.sm.run(testtext), expected)
@@ -221,18 +221,17 @@ class EmptyStateTests(unittest.TestCase):
         self.assertEqual(len(self.state.transitions), 0)
         self.state.add_transitions(['None'], {'None': None})
         self.assertEqual(len(self.state.transitions), 1)
-        self.assertRaises(statemachine.UnknownTransitionError,
-                          self.state.add_transitions, ['bogus'], {})
-        self.assertRaises(statemachine.DuplicateTransitionError,
-                          self.state.add_transitions, ['None'],
-                          {'None': None})
+        with self.assertRaises(statemachine.UnknownTransitionError):
+            self.state.add_transitions(['bogus'], {})
+        with self.assertRaises(statemachine.DuplicateTransitionError):
+            self.state.add_transitions(['None'], {'None': None})
 
     def test_add_transition(self):
         self.assertEqual(len(self.state.transitions), 0)
         self.state.add_transition('None', None)
         self.assertEqual(len(self.state.transitions), 1)
-        self.assertRaises(statemachine.DuplicateTransitionError,
-                          self.state.add_transition, 'None', None)
+        with self.assertRaises(statemachine.DuplicateTransitionError):
+            self.state.add_transition('None', None)
 
     def test_remove_transition(self):
         self.assertEqual(len(self.state.transitions), 0)
@@ -240,8 +239,8 @@ class EmptyStateTests(unittest.TestCase):
         self.assertEqual(len(self.state.transitions), 1)
         self.state.remove_transition('None')
         self.assertEqual(len(self.state.transitions), 0)
-        self.assertRaises(statemachine.UnknownTransitionError,
-                          self.state.remove_transition, 'None')
+        with self.assertRaises(statemachine.UnknownTransitionError):
+            self.state.remove_transition('None')
 
     def test_make_transition(self):
         dummy = re.compile('dummy')
@@ -250,10 +249,10 @@ class EmptyStateTests(unittest.TestCase):
         self.assertEqual(self.state.make_transition('nop'),
                          (dummy, self.state.nop,
                           self.state.__class__.__name__))
-        self.assertRaises(statemachine.TransitionPatternNotFound,
-                          self.state.make_transition, 'None')
-        self.assertRaises(statemachine.TransitionMethodNotFound,
-                          self.state.make_transition, 'bogus')
+        with self.assertRaises(statemachine.TransitionPatternNotFound):
+            self.state.make_transition('None')
+        with self.assertRaises(statemachine.TransitionMethodNotFound):
+            self.state.make_transition('bogus')
 
     def test_make_transitions(self):
         dummy = re.compile('dummy')
diff --git a/docutils/test/test_utils.py b/docutils/test/test_utils.py
index 31c4ec7a7..5e95818eb 100755
--- a/docutils/test/test_utils.py
+++ b/docutils/test/test_utils.py
@@ -66,8 +66,9 @@ class ReporterTests(unittest.TestCase):
                          'test data:: (ERROR/3) an error\n')
 
     def test_level4(self):
-        self.assertRaises(utils.SystemMessage, self.reporter.system_message, 4,
-                          'a severe error, raises an exception')
+        with self.assertRaises(utils.SystemMessage):
+            self.reporter.system_message(
+                4, 'a severe error, raises an exception')
         self.assertEqual(self.stream.getvalue(), 'test data:: (SEVERE/4) '
                          'a severe error, raises an exception\n')
 
@@ -149,20 +150,18 @@ class QuietReporterTests(unittest.TestCase):
 class NameValueTests(unittest.TestCase):
 
     def test_extract_name_value(self):
-        self.assertRaises(utils.NameValueError, utils.extract_name_value,
-                          'hello')
-        self.assertRaises(utils.NameValueError, utils.extract_name_value,
-                          'hello')
-        self.assertRaises(utils.NameValueError, utils.extract_name_value,
-                          '=hello')
-        self.assertRaises(utils.NameValueError, utils.extract_name_value,
-                          'hello=')
-        self.assertRaises(utils.NameValueError, utils.extract_name_value,
-                          'hello="')
-        self.assertRaises(utils.NameValueError, utils.extract_name_value,
-                          'hello="something')
-        self.assertRaises(utils.NameValueError, utils.extract_name_value,
-                          'hello="something"else')
+        with self.assertRaises(utils.NameValueError):
+            utils.extract_name_value('hello')
+        with self.assertRaises(utils.NameValueError):
+            utils.extract_name_value('=hello')
+        with self.assertRaises(utils.NameValueError):
+            utils.extract_name_value('hello=')
+        with self.assertRaises(utils.NameValueError):
+            utils.extract_name_value('hello="')
+        with self.assertRaises(utils.NameValueError):
+            utils.extract_name_value('hello="something')
+        with self.assertRaises(utils.NameValueError):
+            utils.extract_name_value('hello="something"else')
         output = utils.extract_name_value(
               """att1=val1 att2=val2 att3="value number '3'" att4=val4""")
         self.assertEqual(output, [('att1', 'val1'), ('att2', 'val2'),
@@ -181,11 +180,11 @@ class ExtensionOptionTests(unittest.TestCase):
               utils.assemble_option_dict(input, self.optionspec),
               {'a': 1, 'bbb': 2.0, 'cdef': ('hol%s' % chr(224))})
         input = utils.extract_name_value('a=1 b=2.0 c=hol%s' % chr(224))
-        self.assertRaises(KeyError, utils.assemble_option_dict,
-                          input, self.optionspec)
+        with self.assertRaises(KeyError):
+            utils.assemble_option_dict(input, self.optionspec)
         input = utils.extract_name_value('a=1 bbb=two cdef=hol%s' % chr(224))
-        self.assertRaises(ValueError, utils.assemble_option_dict,
-                          input, self.optionspec)
+        with self.assertRaises(ValueError):
+            utils.assemble_option_dict(input, self.optionspec)
 
     def test_extract_extension_options(self):
         field_list = nodes.field_list()
@@ -205,32 +204,29 @@ class ExtensionOptionTests(unittest.TestCase):
               {'a': 1, 'bbb': 2.0,
                'cdef': 'hol\u00e0',
                'empty': None})
-        self.assertRaises(KeyError, utils.extract_extension_options,
-                          field_list, {})
+        with self.assertRaises(KeyError):
+            utils.extract_extension_options(field_list, {})
         field_list += nodes.field(
               '', nodes.field_name('', 'cdef'),
               nodes.field_body('', nodes.paragraph('', 'one'),
                                nodes.paragraph('', 'two')))
-        self.assertRaises(utils.BadOptionDataError,
-                          utils.extract_extension_options,
-                          field_list, self.optionspec)
+        with self.assertRaises(utils.BadOptionDataError):
+            utils.extract_extension_options(field_list, self.optionspec)
         field_list[-1] = nodes.field(
               '', nodes.field_name('', 'cdef bad'),
               nodes.field_body('', nodes.paragraph('', 'no arguments')))
-        self.assertRaises(utils.BadOptionError,
-                          utils.extract_extension_options,
-                          field_list, self.optionspec)
+        with self.assertRaises(utils.BadOptionError):
+            utils.extract_extension_options(field_list, self.optionspec)
         field_list[-1] = nodes.field(
               '', nodes.field_name('', 'cdef'),
               nodes.field_body('', nodes.paragraph('', 'duplicate')))
-        self.assertRaises(utils.DuplicateOptionError,
-                          utils.extract_extension_options,
-                          field_list, self.optionspec)
+        with self.assertRaises(utils.DuplicateOptionError):
+            utils.extract_extension_options(field_list, self.optionspec)
         field_list[-2] = nodes.field(
               '', nodes.field_name('', 'unkown'),
               nodes.field_body('', nodes.paragraph('', 'unknown')))
-        self.assertRaises(KeyError, utils.extract_extension_options,
-                          field_list, self.optionspec)
+        with self.assertRaises(KeyError):
+            utils.extract_extension_options(field_list, self.optionspec)
 
 
 class HelperFunctionTests(unittest.TestCase):
@@ -381,8 +377,8 @@ class StylesheetFunctionTests(unittest.TestCase):
         # must not be used together
         self.stylesheet = 'ham.css, missing.css'
         self.stylesheet_path = 'man.css, miss2.css'
-        self.assertRaises(AssertionError,
-                          utils.get_stylesheet_list, self)
+        with self.assertRaises(AssertionError):
+            utils.get_stylesheet_list(self)
 
 
 
diff --git a/docutils/test/test_writers/test_docutils_xml.py b/docutils/test/test_writers/test_docutils_xml.py
index c6f8bb434..0ee39a020 100755
--- a/docutils/test/test_writers/test_docutils_xml.py
+++ b/docutils/test/test_writers/test_docutils_xml.py
@@ -196,8 +196,8 @@ class DocutilsXMLTestCase(DocutilsTestSupport.StandardTestCase):
              '<test>inline raw XML&lt;/test>\n'])
         settings['halt_level'] = 2 # convert info messages to exceptions
         settings['warning_stream'] = ''
-        self.assertRaises(docutils.utils.SystemMessage,
-                          publish_xml, settings, invalid_raw_xml_source)
+        with self.assertRaises(docutils.utils.SystemMessage):
+            publish_xml(settings, invalid_raw_xml_source)
 
 
 if __name__ == '__main__':
diff --git a/docutils/test/test_writers/test_get_writer_class.py b/docutils/test/test_writers/test_get_writer_class.py
index f347db68d..06edbf931 100644
--- a/docutils/test/test_writers/test_get_writer_class.py
+++ b/docutils/test/test_writers/test_get_writer_class.py
@@ -23,8 +23,8 @@ class GetWriterClassTestCase(DocutilsTestSupport.StandardTestCase):
         # raises ImportError on failure
 
     def test_bogus_writer(self):
-        self.assertRaises(ImportError,
-                          get_writer_class, 'nope')
+        with self.assertRaises(ImportError):
+            get_writer_class('nope')
 
     def test_local_writer(self):
         # requires local-writer.py in test directory (testroot)
diff --git a/docutils/test/test_writers/test_html5_polyglot_misc.py b/docutils/test/test_writers/test_html5_polyglot_misc.py
index e24f61080..3f87d10ec 100644
--- a/docutils/test/test_writers/test_html5_polyglot_misc.py
+++ b/docutils/test/test_writers/test_html5_polyglot_misc.py
@@ -9,7 +9,6 @@ Miscellaneous HTML writer tests.
 """
 
 import os
-import warnings
 
 if __name__ == '__main__':
     import __init__
@@ -138,17 +137,14 @@ class SettingsTestCase(DocutilsTestSupport.StandardTestCase):
         self.assertIn('dl.docutils dd {\n  margin-bottom: 0.5em }', styles)
 
     def test_future_warnings(self):
-        """Warn about changing defaults."""
-        mys={'_disable_config': True,
-             'embed_images': False,
-             }
-        with warnings.catch_warnings(record=True) as wngs:
-            warnings.simplefilter("always")
+        """Warn about deprecated setting name."""
+        my_settings={'_disable_config': True,
+                     'embed_images': False,
+                     }
+        with self.assertWarnsRegex(FutureWarning,
+                                   '"embed_images" will be removed'):
             core.publish_string('warnings test', writer_name='html5',
-                                settings_overrides=mys)
-            n_w = sum(issubclass(wng.category, FutureWarning)
-                      for wng in wngs)
-            self.assertTrue(n_w > 0, "Expected a FutureWarning.")
+                                settings_overrides=my_settings)
 
 
 class MathTestCase(DocutilsTestSupport.StandardTestCase):
diff --git a/docutils/test/test_writers/test_latex2e_misc.py b/docutils/test/test_writers/test_latex2e_misc.py
index 0e0a65454..eedec8ed8 100644
--- a/docutils/test/test_writers/test_latex2e_misc.py
+++ b/docutils/test/test_writers/test_latex2e_misc.py
@@ -15,7 +15,6 @@
 """
 Miscellaneous LaTeX writer tests.
 """
-import warnings
 
 if __name__ == '__main__':
     import __init__
@@ -58,17 +57,19 @@ class WarningsTestCase(DocutilsTestSupport.StandardTestCase):
 
     def test_future_warnings(self):
         """Warn about changing defaults."""
+        # Warn only if not set (uncommenting should make test fail):
         mysettings={'_disable_config': True,
                     # 'use_latex_citations': False,
                     # 'legacy_column_widths': True,
                    }
-        with warnings.catch_warnings(record=True) as wngs:
-            warnings.simplefilter("always")
+        with self.assertWarnsRegex(FutureWarning,
+                                   '"legacy_column_widths" will change'):
+            core.publish_string('warnings test', writer_name='latex',
+                                settings_overrides=mysettings)
+        with self.assertWarnsRegex(FutureWarning,
+                                   '"use_latex_citations" will change'):
             core.publish_string('warnings test', writer_name='latex',
                                 settings_overrides=mysettings)
-            n_w = sum(issubclass(wng.category, FutureWarning)
-                      for wng in wngs)
-            self.assertTrue(n_w > 1, "Expected 2 FutureWarnings.")
 
 
 if __name__ == '__main__':