[IMP] test discovery, documentation, deprecation warnings

* document and warn that checks and fast_suite in tests sub-packages are
  deprecated and have no effect
* avoid iterating all currently loaded modules when looking for test
  modules in a tests sub-package
* replace use of __import__ by importlib

Fixes #3152

doc/reference/testing.rst

@@ -24,8 +24,16 @@ and ``__init__.py`` contains::
 
     from . import test_foo, test_bar
 
-.. note:: test modules which are not imported from ``tests/__init__.py`` will
-          not be run
+.. warning::
+
+    test modules which are not imported from ``tests/__init__.py`` will not be
+    run
+
+.. versionchanged:: 8.0
+
+    previously, the test runner would only run modules added to two lists
+    ``fast_suite`` and ``checks`` in ``tests/__init__.py``. In 8.0 it will
+    run all imported modules
 
 The test runner will simply run any test case, as described in the official
 `unittest documentation`_, but Odoo provides a number of utilities and helpers
@@ -46,8 +54,8 @@ been installed, and not run right after the module installation:
 .. autofunction:: openerp.tests.common.post_install
 
 The most common situation is to use
-:class:`~openerp.tests.common.TransactionCase` and test a property of a of a
-model in each method::
+:class:`~openerp.tests.common.TransactionCase` and test a property of a model
+in each method::
 
     class TestModelA(common.TransactionCase):
         def test_some_action(self):
@@ -67,7 +75,7 @@ Tests are automatically run when installing or updating modules if
 Odoo server.
 
 As of Odoo 8, running tests outside of the install/update cycle is not
-
+supported.
 
 .. _unittest2: http://pypi.python.org/pypi/unittest2
 .. _unittest documentation: https://docs.python.org/2/library/unittest.html

openerp/modules/module.py

@@ -22,6 +22,8 @@
 
 import functools
 import imp
+import importlib
+import inspect
 import itertools
 import logging
 import os
@@ -366,23 +368,26 @@ def adapt_version(version):
     return version
 
 def get_test_modules(module):
-    """ Return a list of module for the addons potentialy containing tests to
+    """ Return a list of module for the addons potentially containing tests to
     feed unittest2.TestLoader.loadTestsFromModule() """
     # Try to import the module
-    module = 'openerp.addons.' + module + '.tests'
+    modpath = 'openerp.addons.' + module
     try:
-        __import__(module)
+        mod = importlib.import_module('.tests', modpath)
     except Exception, e:
         # If module has no `tests` sub-module, no problem.
         if str(e) != 'No module named tests':
             _logger.exception('Can not `import %s`.', module)
         return []
 
-    # include submodules too
-    result = [mod_obj for name, mod_obj in sys.modules.iteritems()
-              if mod_obj # mod_obj can be None
-              if name.startswith(module)
-              if re.search(r'test_\w+$', name)]
+    if hasattr(mod, 'fast_suite') or hasattr(mod, 'checks'):
+        _logger.warn(
+            "Found deprecated fast_suite or checks attribute in test module "
+            "%s. These have no effect in or after version 8.0.",
+            mod.__name__)
+
+    result = [mod_obj for name, mod_obj in inspect.getmembers(mod, inspect.ismodule)
+              if name.startswith('test_')]
     return result
 
 # Use a custom stream object to log the test executions.