introduce --ignore option to ignore paths during collection

--HG--
branch : trunk

CHANGELOG

@@ -1,6 +1,9 @@
 Changes between 1.1.2 and 1.1.1
 =====================================
 
+- new option: --ignore will prevent specified path from collection. 
+  Can be specified multiple times. 
+
 - install 'py.test' and `py.which` with a ``-$VERSION`` suffix to
   disambiguate between Python3, python2.X, Jython and PyPy installed versions. 
 

py/impl/test/collect.py

@@ -394,8 +394,12 @@ class Directory(FSCollector):
         return l
 
     def _ignore(self, path):
-        ignore_paths = self.config.getconftest_pathlist("collect_ignore", path=path)
+        ignore_paths = self.config.getconftest_pathlist("collect_ignore", 
-        return ignore_paths and path in ignore_paths
+            path=path) or []
+        excludeopt = self.config.getvalue("ignore")
+        if excludeopt:
+            ignore_paths.extend([py.path.local(x) for x in excludeopt])
+        return path in ignore_paths
         # XXX more refined would be: 
         if ignore_paths:
             for p in ignore_paths:

py/plugin/pytest_default.py

@@ -51,6 +51,8 @@ def pytest_addoption(parser):
     group._addoption('-x', '--exitfirst',
                action="store_true", dest="exitfirst", default=False,
                help="exit instantly on first error or failed test."),
+    group.addoption("--ignore", action="append", metavar="path", 
+        help="ignore path during collection (multi-allowed).")
     group._addoption('-k',
         action="store", dest="keyword", default='',
         help="only run test items matching the given "

testing/plugin/test_pytest_default.py

@@ -30,6 +30,15 @@ def test_plugin_already_exists(testdir):
     assert config.option.plugins == ['default']
     config.pluginmanager.do_configure(config)
 
+def test_exclude(testdir):
+    hellodir = testdir.mkdir("hello")
+    hellodir.join("test_hello.py").write("x y syntaxerror")
+    hello2dir = testdir.mkdir("hello2")
+    hello2dir.join("test_hello2.py").write("x y syntaxerror")
+    testdir.makepyfile(test_ok="def test_pass(): pass")
+    result = testdir.runpytest("--ignore=hello", "--ignore=hello2")
+    assert result.ret == 0
+    assert result.stdout.fnmatch_lines(["*1 passed*"])
 
 class TestDistOptions:
     def setup_method(self, method):