check match= message in own depreation warning tests

- adapted from 195855c

tests/backend/test_piping.py

@@ -75,7 +75,7 @@ def test_pipe_pipe_invalid_data_mocked(mocker, sentinel, mock_run, quiet):
          reason='https://gitlab.com/graphviz/graphviz/-/issues/1269'))])
 def test_pipe(capsys, engine, format_, renderer, formatter, pattern,
               data=b'graph { spam }'):
-    with pytest.deprecated_call():
+    with pytest.deprecated_call(match=r'3 positional args'):
         out = graphviz.pipe(engine, format_, data,
                             renderer, formatter).decode('ascii')
 

tests/backend/test_rendering.py

@@ -60,7 +60,7 @@ def test_render(capsys, tmp_path, engine, format_, renderer, formatter,
     assert lpath.write_bytes(data) == len(data) == lpath.stat().st_size
     rendered = lpath.with_suffix(f'{lpath.suffix}.{expected_suffix}')
 
-    with pytest.deprecated_call():
+    with pytest.deprecated_call(match=r'3 positional args'):
         result = graphviz.render(engine, format_, str(lpath),
                                  renderer, formatter)
 

tests/test_all_classes.py

@@ -210,7 +210,7 @@ def test_save_mocked(mocker, dot, filename='nonfilename', directory='nondirector
     mock_makedirs = mocker.patch('os.makedirs', autospec=True)
     mock_open = mocker.patch('builtins.open', mocker.mock_open())
 
-    with pytest.deprecated_call():
+    with pytest.deprecated_call(match=r'2 positional args\b'):
         assert dot.save(filename, directory) == dot.filepath
 
     assert dot.filename == filename

tests/test_sources.py

@@ -42,22 +42,23 @@ def test_filepath(platform, source):
 
 
 def test_from_file(tmp_path, filename='hello.gv', directory='source_hello',
-                   data='digraph { hello -> world }', encoding='utf-8'):
+                   data='digraph { hello -> world }', encoding='utf-8',
+                   deprecation_match=r'2 positional args\b'):
     lpath = tmp_path / directory
     lpath.mkdir()
     (lpath / filename).write_text(data, encoding=encoding)
 
-    with pytest.deprecated_call():
+    with pytest.deprecated_call(match=deprecation_match):
         source = graphviz.Source.from_file(filename, str(lpath))
     assert source.encoding == 'utf-8'
 
-    with pytest.deprecated_call():
+    with pytest.deprecated_call(match=deprecation_match):
         source = graphviz.Source.from_file(filename, str(lpath), encoding=None)
     assert source.encoding == locale.getpreferredencoding()
 
     renderer = 'xdot'
     formatter = 'core'
-    with pytest.deprecated_call():
+    with pytest.deprecated_call(match=deprecation_match):
         source = graphviz.Source.from_file(filename, str(lpath),
                                            encoding=encoding,
                                            renderer=renderer,