Add relative to other tests 'run' mark 'after' and 'before' kwargs

docs/source/index.rst

@@ -121,6 +121,47 @@ You can also use markers such as "first", "second", "last", and "second_to_last"
     =========================== 4 passed in 0.02 seconds ===========================
 
 
+Relative to other tests
+-----------------------
+
+Tests can be defined relative to others with "before" and "after" parameters.
+
+.. code:: python
+
+ import pytest
+
+ @pytest.mark.run(after='test_second')
+ def test_third():
+     assert True
+
+ def test_second():
+     assert True
+
+ @pytest.mark.run(before='test_second')
+     def test_first():
+         assert True
+
+::
+
+    $ py.test test_foo.py -vv
+    ============================= test session starts ==============================
+    platform darwin -- Python 2.7.5 -- py-1.4.20 -- pytest-2.5.2 -- env/bin/python
+    plugins: ordering
+    collected 3 items
+
+    test_foo.py:11: test_first PASSED
+    test_foo.py:7: test_second PASSED
+    test_foo.py:4: test_third PASSED
+
+    =========================== 4 passed in 0.02 seconds ===========================
+
+
+
+    .. toctree::
+       :maxdepth: 2
+
+    .. _markers: https://pytest.org/latest/mark.html
+
 Aspirational
 ============
 
@@ -204,44 +245,3 @@ By number
 
     =========================== 4 passed in 0.02 seconds ===========================
 
-
-Relative to other tests
------------------------
-
-
-.. code:: python
-
- import pytest
-
- @pytest.mark.run(after='test_second')
- def test_third():
-     assert True
-
- def test_second():
-     assert True
-
- @pytest.mark.run(before='test_second')
- def test_first():
-     assert True
-
-::
-
-    $ py.test test_foo.py -vv
-    ============================= test session starts ==============================
-    platform darwin -- Python 2.7.5 -- py-1.4.20 -- pytest-2.5.2 -- env/bin/python
-    plugins: ordering
-    collected 3 items
-
-    test_foo.py:11: test_first PASSED
-    test_foo.py:7: test_second PASSED
-    test_foo.py:4: test_third PASSED
-
-    =========================== 4 passed in 0.02 seconds ===========================
-
-
-
-.. toctree::
-   :maxdepth: 2
-
-.. _markers: https://pytest.org/latest/mark.html
-

pytest_ordering/__init__.py

@@ -2,6 +2,7 @@
 from ._version import __version__
 
 import operator
+import warnings
 
 import pytest
 
@@ -47,7 +48,7 @@ def pytest_configure(config):
 
 
 def pytest_collection_modifyitems(session, config, items):
-    grouped_items = {}
+    grouped_items, before_items, after_items = ({}, {}, {})
 
     for item in items:
 
@@ -62,6 +63,16 @@ def pytest_collection_modifyitems(session, config, items):
 
         if mark:
             order = mark.kwargs.get('order')
+            if order is None:
+                before = mark.kwargs.get('before')
+                if before:
+                    before_items.setdefault(before, []).append(item)
+                    continue
+
+                after = mark.kwargs.get('after')
+                if after:
+                    after_items.setdefault(after, []).append(item)
+                    continue
         else:
             order = None
 
@@ -80,3 +91,60 @@ def pytest_collection_modifyitems(session, config, items):
     sorted_items.extend([i[1] for i in end_list])
 
     items[:] = [item for sublist in sorted_items for item in sublist]
+
+    def _get_item_index_by_name(item_name):
+        index = None
+        for i, item in enumerate(items):
+            if getattr(item, 'name') == item_name:
+                index = i
+                break
+        return index
+
+    for before_item_relative, _before_items in before_items.items():
+        index = _get_item_index_by_name(before_item_relative)
+        if index is not None:
+            for before_item in _before_items:
+                items.insert(index, before_item)
+        else:
+            if len(_before_items) == 1:
+                message_schema = "%s, indicated at parameter before of" \
+                               + " %s, doesn't exist"
+                message = message_schema % (before_item_relative,
+                                            _before_items[0].name)
+            else:
+                message_schema = "%s, indicated at parameter before of" \
+                               + " %s, doesn't exist"
+                test_names = ""
+                for i, before_item in enumerate(_before_items):
+                    test_names += before_item.name
+                    if i < len(_before_items) - 2:
+                        test_names += ", "
+                    elif i == len(_before_items) - 2:
+                        test_names += " and "
+                message = message_schema % (before_item_relative, test_names)
+            warnings.warn(message, SyntaxWarning)
+            items.extend(_before_items)
+    for after_item_relative, _after_items in after_items.items():
+        index = _get_item_index_by_name(after_item_relative)
+        if index is not None:
+            for after_item in _after_items:
+                items.insert(index+1, after_item)
+        else:
+            if len(_after_items) == 1:
+                message_schema = "%s, indicated at parameter after of" \
+                               + " %s, doesn't exist"
+                message = message_schema % (after_item_relative,
+                                            _after_items[0].name)
+            else:
+                message_schema = "%s, indicated at parameter after of" \
+                               + " %s, doesn't exist"
+                test_names = ""
+                for i, after_item in enumerate(_after_items):
+                    test_names += after_item.name
+                    if i < len(_after_items) - 2:
+                        test_names += ", "
+                    elif i == len(_after_items) - 2:
+                        test_names += " and "
+                message = message_schema % (after_item_relative, test_names)
+            warnings.warn(message, SyntaxWarning)
+            items.extend(_after_items)

tests/test_ordering.py

@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 import re
+import warnings
 
 import pytest
 
@@ -268,6 +269,72 @@ def test_5(self): pass
     assert item_names_for(tests_content) == ['test_3', 'test_4', 'test_5', 'test_1', 'test_2']
 
 
+def test_relative_to_other_tests(item_names_for):
+    tests_content = """
+    import pytest
+
+    @pytest.mark.run(after='test_2')
+    def test_3(): pass
+
+    def test_2(): pass
+
+    @pytest.mark.run(before='test_2')
+    def test_1(): pass
+    """
+    assert item_names_for(tests_content) == ['test_1', 'test_2', 'test_3']
+
+def test_relative_to_other_invalid_tests(item_names_for):
+    tests_content = """
+    import pytest
+
+    @pytest.mark.run(before='test_A')
+    def test_1(): pass
+
+    def test_2(): pass
+
+    @pytest.mark.run(after='test_B')
+    def test_3(): pass
+
+    @pytest.mark.run(before='test_C')
+    def test_4(): pass
+
+    @pytest.mark.run(before='test_C')
+    def test_5(): pass
+
+    @pytest.mark.run(before='test_C')
+    def test_6(): pass
+
+    @pytest.mark.run(after='test_D')
+    def test_7(): pass
+
+    @pytest.mark.run(after='test_D')
+    def test_8(): pass
+    """
+
+    with warnings.catch_warnings(record=True) as catched_warnings:
+        expected_item_names = [
+            'test_2', 'test_1', 'test_4', 'test_5',
+            'test_6', 'test_3', 'test_7', 'test_8',
+        ]
+        for item_name in item_names_for(tests_content):
+            assert item_name in expected_item_names
+
+        expected_warning_messages = [
+            "test_A, indicated at parameter before of test_1, doesn't exist",
+            "test_B, indicated at parameter after of test_3, doesn't exist",
+            "test_C, indicated at parameter before of test_4, test_5 and test_6, doesn't exist",
+            "test_D, indicated at parameter after of test_7 and test_8, doesn't exist",
+        ]
+
+        n_other_warnings = 0        
+        for w in catched_warnings:
+            if not issubclass(w.category, SyntaxWarning):
+                n_other_warnings += 1
+                continue
+            assert w.message.__str__() in expected_warning_messages
+        assert len(expected_warning_messages) + n_other_warnings == len(catched_warnings)
+
+
 def test_markers_registered(capsys):
     pytest.main(['--markers'])
     out, err = capsys.readouterr()