Document that the dependency marker may be applied to a class as a

whole.  Close #39.

doc/examples/mark-class.py

@@ -0,0 +1,21 @@
+import pytest
+
+
+@pytest.mark.dependency()
+@pytest.mark.xfail(reason="deliberate fail")
+def test_f():
+    assert False
+
+
+@pytest.mark.dependency(depends=["test_f"])
+class TestClass(object):
+
+    def test_a(self):
+        pass
+
+    @pytest.mark.dependency()
+    def test_b(self):
+        pass
+
+    def test_c(self):
+        pass

doc/src/usage.rst

@@ -73,6 +73,22 @@ explicit `name` argument to the :func:`pytest.mark.dependency` marker.
    The name of the class is prepended to the method name to form the
    default name for the test.
 
+Applying the dependency marker to a class as a whole
+----------------------------------------------------
+
+The :func:`pytest.mark.dependency` marker may also be applied to a test
+class as a whole.  This has the same effect as applying that marker
+with the same arguments to each method of the class individually.
+Consider:
+
+.. literalinclude:: ../examples/mark-class.py
+
+The tests `TestClass::test_a` and `TestClass::test_c` will be skipped,
+because they depend on `test_f`.  But `TestClass::test_b` will be run,
+because it is individually marked.  The marker on the test method
+overrides the marker on the class and thus effectively clears the
+dependency list for `TestClass::test_b`.
+
 .. _usage-parametrized:
 
 Parametrized tests

tests/test_09_examples_usage.py

@@ -60,6 +60,21 @@ def test_testclass(ctestdir):
     """)
 
 
+def test_mark_class(ctestdir):
+    """Applying the dependency marker to a class as a whole
+    """
+    with get_example("mark-class.py").open("rt") as f:
+        ctestdir.makepyfile(f.read())
+    result = ctestdir.runpytest("--verbose")
+    result.assert_outcomes(passed=1, skipped=2, failed=0, xfailed=1)
+    result.stdout.re_match_lines(r"""
+        .*::test_f XFAIL(?:\s+\(.*\))?
+        .*::TestClass::test_a SKIPPED(?:\s+\(.*\))?
+        .*::TestClass::test_b PASSED
+        .*::TestClass::test_c SKIPPED(?:\s+\(.*\))?
+    """)
+
+
 def test_parametrized(ctestdir):
     """Parametrized tests
     """