ENH: make OuputChecker pluggable in the pytest layer

Author: ev-br

scpdt/plugin.py

@@ -213,7 +213,6 @@ def collect(self):
         runner = _get_runner(self.config,
             verbose=False,
             optionflags=optionflags,
-            checker=DTChecker(config=self.config.dt_config)
         )
 
         # strategy='api': discover doctests in public, non-deprecated objects in module
@@ -228,7 +227,7 @@ def collect(self):
                 yield pydoctest.DoctestItem.from_parent(
                     self, name=test.name, runner=runner, dtest=test
                 )
-        
+
 
 class DTTextfile(DoctestTextfile):
     """
@@ -253,7 +252,6 @@ def collect(self):
         runner = _get_runner(self.config,
             verbose=False,
             optionflags=optionflags,
-            checker=DTChecker(config=self.config.dt_config)
         )
 
         # Plug in an instance of `DTParser` which parses the doctest examples from the text file and
@@ -268,7 +266,7 @@ def collect(self):
             )
 
 
-def _get_runner(config, checker, verbose, optionflags):
+def _get_runner(config, verbose, optionflags):
     """
     Override function to return an instance of PytestDTRunner.
     
@@ -321,5 +319,5 @@ def report_unexpected_exception(self, out, test, example, exc_info):
                 out.append(failure)
             else:
                 raise failure
-            
-    return PytestDTRunner(checker=checker, verbose=verbose, optionflags=optionflags, config=config.dt_config)
+
+    return PytestDTRunner(verbose=verbose, optionflags=optionflags, config=config.dt_config)

scpdt/tests/test_pytest_configuration.py

@@ -42,3 +42,38 @@ def test_local_file_cases(pytester):
     python_file = PosixPath(path_str)
     result = pytester.inline_run(python_file, "--doctest-modules")
     assert result.ret == pytest.ExitCode.OK
+
+
+def test_alt_checker(pytester):
+    """Test an alternative Checker."""
+
+    # create a temporary conftest.py file
+    pytester.makeconftest(
+        """
+        import doctest
+        from scpdt.conftest import dt_config
+
+        class Vanilla(doctest.OutputChecker):
+            def __init__(self, config):
+                pass
+
+        dt_config.CheckerKlass = Vanilla
+    """
+    )
+
+    # create a temporary pytest test file
+    f = pytester.makepyfile(
+        """
+        def func():
+            '''
+            >>> 2 / 3     # fails with vanilla doctest.OutputChecker
+            0.667
+            '''
+            pass
+    """
+    )
+
+    # run all tests with pytest
+    result = pytester.inline_run(f, '--doctest-modules')
+    assert result.ret == pytest.ExitCode.TESTS_FAILED
+