Merge pull request #187 from cdent/fix-pytest-yield

Fix pytest yield

docs/source/loader.rst

@@ -67,7 +67,35 @@ pytest
 .. _pytest_loader:
 
 Since pytest does not support the ``load_tests`` system, a different
-way of generating tests is required. A test file must be created
+way of generating tests is required. Two techniques are supported.
+
+The original method (described below) used yield statements to
+generate tests which pytest would collect. This style of tests is
+deprecated as of ``pytest>=3.0`` so a new style using pytest
+fixtures has been developed.
+
+pytest >= 3.0
+-------------
+
+In the newer technique, a test file is created that uses the
+``pytest_generate_tests`` hook. Special care must be taken to always
+import the ``test_pytest`` method which is the base test that the
+pytest hook parametrizes to generate the tests from the YAML files.
+Without the method, the hook will not be called and no tests generated.
+
+Here is a simple example file:
+
+.. literalinclude:: pytest3.0-example.py
+   :language: python
+
+This can then be run with the usual pytest commands. For example::
+
+   py.test -svx pytest3.0-example.py
+
+pytest < 3.0
+------------
+
+When using the older technique, test file must be created
 that calls :meth:`~gabbi.driver.py_test_generator` and yields the
 generated tests. That will look a bit like this:
 
@@ -78,14 +106,11 @@ This can then be run with the usual pytest commands. For example::
 
    py.test -svx pytest-example.py
 
-.. warning:: In ``pytest>=3.0`` yield tests are deprecated and using
-             them will cause pytest to produce a warning. If you
-             wish to ignore and hide these warnings add the
-             ``--disable-pytest-warnings`` parameter to the
-             invocation of ``py.test`` or use a version of pytest
-             earlier than version ``3.0``. A new way of creating gabbi
-             tests that works more effectively with modern pytest is
-             being developed.
+The older technique will continue to work with all versions of
+``pytest<4.0`` but ``>=3.0`` will produce warnings. If you want to
+use the older technique but not see the warnings add
+``--disable-pytest-warnings`` parameter to the invocation of
+``py.test``.
 
 .. _source distribution: https://github.com/cdent/gabbi
 .. _the tutorial repo: https://github.com/cdent/gabbi-demo

docs/source/pytest3.0-example.py

@@ -0,0 +1,30 @@
+"""A sample pytest module for pytest >= 3.0."""
+
+# For pathname munging
+import os
+
+# The module that py_test_generator comes from.
+from gabbi import driver
+
+# We need test_pytest so that pytest test collection works properly.
+# Without this, the pytest_generate_tests method below will not be
+# called.
+from gabbi.driver import test_pytest  # noqa
+
+# We need access to the WSGI application that hosts our service
+from myapp import wsgiapp
+
+# We're using fixtures in the YAML files, we need to know where to
+# load them from.
+from myapp.test import fixtures
+
+# By convention the YAML files are put in a directory named
+# "gabbits" that is in the same directory as the Python test file.
+TESTS_DIR = 'gabbits'
+
+
+def pytest_generate_tests(metafunc):
+    test_dir = os.path.join(os.path.dirname(__file__), TESTS_DIR)
+    driver.py_test_generator(
+        test_dir, intercept=wsgiapp.app,
+        fixture_module=fixtures, metafunc=metafunc)

gabbi/driver.py

@@ -129,7 +129,8 @@ def build_tests(path, loader, host=None, port=8001, intercept=None,
 def py_test_generator(test_dir, host=None, port=8001, intercept=None,
                       prefix=None, test_loader_name=None,
                       fixture_module=None, response_handlers=None,
-                      content_handlers=None, require_ssl=False, url=None):
+                      content_handlers=None, require_ssl=False, url=None,
+                      metafunc=None):
     """Generate tests cases for py.test
 
     This uses build_tests to create TestCases and then yields them in
@@ -151,15 +152,43 @@ def py_test_generator(test_dir, host=None, port=8001, intercept=None,
                         prefix=prefix, require_ssl=require_ssl,
                         url=url)
 
+    test_list = []
     for test in tests:
         if hasattr(test, '_tests'):
             # Establish fixtures as if they were tests. These will
             # be cleaned up by the pytester plugin.
-            yield 'start_%s' % test._tests[0].__class__.__name__, \
-                test.start, result
+            test_list.append(('start_%s' % test._tests[0].__class__.__name__,
+                              test.start, result))
             for subtest in test:
-                yield '%s' % subtest.__class__.__name__, subtest, result
-            yield 'stop_%s' % test._tests[0].__class__.__name__, test.stop
+                test_list.append(('%s' % subtest.__class__.__name__,
+                                  subtest, result))
+            test_list.append(('stop_%s' % test._tests[0].__class__.__name__,
+                              test.stop))
+
+    if metafunc:
+        if metafunc.function == test_pytest:
+            ids = []
+            args = []
+            for test in test_list:
+                if len(test) >= 3:
+                    name, method, arg = test
+                else:
+                    name, method = test
+                    arg = None
+                ids.append(name)
+                args.append((method, arg))
+
+            metafunc.parametrize("test, result", argvalues=args, ids=ids)
+    else:
+        # preserve backwards compatibility with old calling style
+        return test_list
+
+
+def test_pytest(test, result):
+    if result:
+        test(result)
+    else:
+        test()
 
 
 def test_suite_from_yaml(loader, test_base_name, test_yaml, test_directory,

gabbi/pytester.py

@@ -30,9 +30,11 @@
 
 def get_cleanname(item):
     """Extract a test name from a pytest Function item."""
-    cleanname = item.name[2:]
-    cleanname = cleanname[:-2]
-    return cleanname
+    if '[' in item.name:
+        cleanname = item.name.split('[', 1)[1]
+        cleanname = cleanname.split(']', 1)[0]
+        return cleanname
+    return item.name
 
 
 def get_suitename(name):
@@ -86,10 +88,13 @@ def a_pytest_collection_modifyitems(items, config):
             continue
         suitename = get_suitename(cleanname)
         if cleanname.startswith('start_'):
-            STARTS[suitename] = item
+            test = item.callspec.params['test']
+            result = item.callspec.params['result']
+            STARTS[suitename] = (test, result)
             deselected.append(item)
         elif cleanname.startswith('stop_'):
-            STOPS[suitename] = item
+            test = item.callspec.params['test']
+            STOPS[suitename] = test
             deselected.append(item)
         else:
             remaining.append(item)
@@ -118,20 +123,11 @@ def pytest_runtest_setup(item):
     run its priors after running this.
     """
     if hasattr(item, 'starter'):
-        try:
-            # Python 2
-            item.starter.function(item.starter.obj.__self__, item._args[0])
-        except TypeError:
-            # Python 3
-            item.starter.function(item._args[0])
+        test, result = item.starter
+        test(result)
 
 
 def pytest_runtest_teardown(item, nextitem):
     """Run a stopper if a test has one."""
     if hasattr(item, 'stopper'):
-        try:
-            # Python 2
-            item.stopper.function(item.stopper.obj.__self__)
-        except TypeError:
-            # Python 3
-            item.stopper.function()
+        item.stopper()

gabbi/tests/test_gabbits_pytest.py

@@ -20,22 +20,19 @@
 import os
 
 from gabbi import driver
+# TODO(cdent): this test_* needs to be imported bare or things do not work
+from gabbi.driver import test_pytest  # noqa
 from gabbi.tests import simple_wsgi
 from gabbi.tests import test_intercept
 
 TESTS_DIR = 'gabbits_intercept'
 
 
-def test_from_build():
-
+def pytest_generate_tests(metafunc):
     os.environ['GABBI_TEST_URL'] = 'takingnames'
     test_dir = os.path.join(os.path.dirname(__file__), TESTS_DIR)
-    test_generator = driver.py_test_generator(
+    driver.py_test_generator(
         test_dir, intercept=simple_wsgi.SimpleWsgi,
         fixture_module=test_intercept,
-        response_handlers=[test_intercept.TestResponseHandler])
-
-    # TODO(cdent): Where is our Python3!
-    # yield from test_generator
-    for test in test_generator:
-        yield test
+        response_handlers=[test_intercept.TestResponseHandler],
+        metafunc=metafunc)