Add support for --indulgent-ordering option

AUTHORS

@@ -2,3 +2,4 @@ Frank Tobia <[email protected]>
 Sergei Chipiga <[email protected]>
 Ben Greene <[email protected]>
 Adam Talsma <[email protected]>
+Andrew Gilbert <[email protected]>

CHANGELOG

@@ -1,3 +1,9 @@
+Unreleased
+---
+### Added
+- #50 Add ``--indulgent-ordering`` to request that the sort from
+  pytest-ordering be run before other plugins.  This allows the built-in
+  ``--failed-first`` implementation to override the ordering.
 
 0.6
 ---

docs/source/index.rst

@@ -114,6 +114,21 @@ You can also use markers such as "first", "second", "last", and "second_to_last"
 
     =========================== 4 passed in 0.02 seconds ===========================
 
+``--indulgent-ordering`` and overriding ordering
+-------------
+
+You may sometimes find that you want to suggest an ordering of tests, while
+allowing it to be overridden for good reson. For example, if you run your test
+suite in parallel and have a number of tests which are particularly slow, it
+might be desirable to start those tests running first, in order to optimize
+your completion time. You can use the pytest-ordering plugin to inform pytest
+of this. Now suppose you also want to prioritize tests which failed during the
+previous run, by using the ``--failed-first`` option. By default,
+pytest-ordering will override the ``--failed-first`` order, but by adding the
+``--indulgent-ordering`` option, you can ask pytest to run the sort from
+pytest-ordering *before* the sort from ``--failed-first``, allowing the failed
+tests to be sorted to the front.
+
 
 Aspirational
 ============

pytest_ordering/__init__.py

@@ -26,17 +26,49 @@
 
 
 def pytest_configure(config):
-    """Register the "run" marker."""
+    """Register the "run" marker and configure the plugin depending on the CLI
+    options"""
 
     config_line = (
         'run: specify ordering information for when tests should run '
         'in relation to one another. Provided by pytest-ordering. '
         'See also: http://pytest-ordering.readthedocs.org/'
     )
     config.addinivalue_line('markers', config_line)
-
-
-def pytest_collection_modifyitems(session, config, items):
+    if config.getoption('indulgent-ordering'):
+        # We need to dynamically add this `tryfirst` decorator to the plugin:
+        # only when the CLI option is present should the decorator be added.
+        # Thus, we manually run the decorator on the class function and
+        # manually replace it.
+        # Python 2.7 didn't allow arbitrary attributes on methods, so we have
+        # to keep the function as a function and then add it to the class as a
+        # pseudomethod.  Since the class is purely for structuring and `self`
+        # is never referenced, this seems reasonable.
+        OrderingPlugin.pytest_collection_modifyitems = pytest.hookimpl(
+                function=modify_items, tryfirst=True)
+    else:
+        OrderingPlugin.pytest_collection_modifyitems = pytest.hookimpl(
+                function=modify_items, trylast=True)
+    config.pluginmanager.register(OrderingPlugin(), 'orderingplugin')
+
+
+def pytest_addoption(parser):
+    """Set up CLI option for pytest"""
+    group = parser.getgroup('ordering')
+    group.addoption('--indulgent-ordering', action='store_true',
+                     dest='indulgent-ordering', help='''Request that the sort \
+order provided by pytest-ordering be applied before other sorting, allowing the \
+other sorting to have priority''')
+
+class OrderingPlugin(object):
+    """
+    Plugin implementation
+
+    By putting this in a class, we are able to dynamically register it after
+    the CLI is parsed.
+    """
+
+def modify_items(session, config, items):
     grouped_items = {}
 
     for item in items:

tests/test_indulgent_ordering.py

@@ -0,0 +1,40 @@
+# -*- coding: utf-8 -*-
+import re
+
+import pytest
+import pytest_ordering
+
+pytest_plugins = ["pytester"]
+
+
+def test_run_marker_registered(capsys, tmpdir):
+    testname = str(tmpdir.join("failing.py"))
+    with open(testname, "w") as fi:
+        fi.write(
+            """
+import pytest
+
+@pytest.mark.second
+def test_me_second():
+    assert True
+
+def test_that_fails():
+    assert False
+
+@pytest.mark.first
+def test_me_first():
+    assert True
+"""
+        )
+    args = ["--quiet", "--color=no", testname]
+    pytest.main(args, [pytest_ordering])
+    out, err = capsys.readouterr()
+    assert "..F" in out
+    args.insert(0, "--ff")
+    pytest.main(args, [pytest_ordering])
+    out, err = capsys.readouterr()
+    assert "..F" in out
+    args.insert(0, "--indulgent-ordering")
+    pytest.main(args, [pytest_ordering])
+    out, err = capsys.readouterr()
+    assert "F.." in out

tests/test_ordering.py

@@ -269,6 +269,6 @@ def test_5(self): pass
 
 
 def test_run_marker_registered(capsys):
-    pytest.main('--markers')
+    pytest.main(['--markers'])
     out, err = capsys.readouterr()
     assert '@pytest.mark.run' in out