Document pytest.py like I documented test_all.py.

1 files changed, 20 insertions, 1 deletions

diff --git a/pytest.py b/pytest.py
index c5a5197a06..7b53c16a13 100755
--- a/pytest.py
+++ b/pytest.py
@@ -1,6 +1,20 @@
 #!/usr/bin/env python
 """
-unit and functional testing with Python.
+PyPy Test runner interface
+--------------------------
+
+Running pytest.py starts py.test, the testing tool
+we use in PyPy.  It is distributed along with PyPy,
+but you may get more information about it at
+http://pytest.org/.
+
+Note that it makes no sense to run all tests at once.
+You need to pick a particular subdirectory and run
+
+    cd pypy/.../test
+    ../../../pytest.py [options]
+
+For more information, use pytest.py -h.
 """
 __all__ = ['main']
 
@@ -23,6 +37,11 @@ from _pytest import core as cmdline
 from _pytest import __version__
 
 if __name__ == '__main__': # if run as a script or by 'python -m pytest'
+    import os
+    if len(sys.argv) == 1 and os.path.dirname(sys.argv[0]) in '.':
+        print >> sys.stderr, __doc__
+        sys.exit(2)
+
     #XXX: sync to upstream later
     import pytest_cov
     raise SystemExit(main(plugins=[pytest_cov]))