Ensure that a module within a namespace package can be found by --pyargs

AUTHORS

@@ -78,6 +78,7 @@ Ronny Pfannschmidt
 Ross Lawley
 Ryan Wooden
 Samuele Pedroni
+Stefano Taschini
 Tom Viner
 Trevor Bekolay
 Wouter van Ackooy

CHANGELOG.rst

@@ -5,6 +5,10 @@
 
 *
 
+* Ensure that a module within a namespace package can be found when it
+  is specified on the command line together with the``--pyargs``
+  option.
+
 * Fix win32 path issue when puttinging custom config file with absolute path 
   in ``pytest.main("-c your_absolute_path")``.
 

_pytest/main.py

@@ -648,8 +648,37 @@ def _recurse(self, path):
         ihook.pytest_collect_directory(path=path, parent=self)
         return True
 
+    def _locate_module(self, modulename, searchpath):
+        """Find the locations of a module or package in the filesytem.
+
+        In case of a presumptive namespace package return all of its possible
+        locations.
+
+        """
+        try:
+            fd, pathname, type_ = imp.find_module(modulename, searchpath)
+        except ImportError:
+            return []
+        else:
+            if fd is not None:
+                fd.close()
+        if type_[2] != imp.PKG_DIRECTORY:
+            return [pathname]
+        else:
+            init_file = os.path.join(pathname, '__init__.py')
+            if os.path.getsize(init_file) == 0:
+                return [pathname]
+            return [pathname] + self._locate_module(
+                modulename,
+                searchpath[searchpath.index(os.path.dirname(pathname)) + 1:])
+
     def _tryconvertpyarg(self, x):
-        mod = None
+        """Convert a dotted module name to a list of file-system locations.
+
+        Always return a list. If the module cannot be found, the list contains
+        just the given argument.
+
+        """
         path = [os.path.abspath('.')] + sys.path
         for name in x.split('.'):
             # ignore anything that's not a proper name here
@@ -658,27 +687,20 @@ def _tryconvertpyarg(self, x):
             # but it's supposed to be considered a filesystem path
             # not a package
             if name_re.match(name) is None:
-                return x
-            try:
-                fd, mod, type_ = imp.find_module(name, path)
-            except ImportError:
-                return x
-            else:
-                if fd is not None:
-                    fd.close()
-
-            if type_[2] != imp.PKG_DIRECTORY:
-                path = [os.path.dirname(mod)]
-            else:
-                path = [mod]
-        return mod
+                return [x]
+            path = self._locate_module(name, path)
+            if len(path) == 0:
+                return [x]
+        return path
 
     def _parsearg(self, arg):
         """ return (fspath, names) tuple after checking the file exists. """
-        arg = str(arg)
-        if self.config.option.pyargs:
-            arg = self._tryconvertpyarg(arg)
         parts = str(arg).split("::")
+        if self.config.option.pyargs:
+            paths = self._tryconvertpyarg(parts[0])
+            if len(paths) != 1:
+                raise pytest.UsageError("Cannot uniquely resolve package directory: " + arg)
+            parts[0] = paths[0]
         relpath = parts[0].replace("/", os.sep)
         path = self.config.invocation_dir.join(relpath, abs=True)
         if not path.check():

testing/acceptance_test.py

@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 import sys
 
 import _pytest._code
@@ -557,6 +558,67 @@ def join_pythonpath(what):
             "*not*found*test_hello*",
         ])
 
+    def test_cmdline_python_namespace_package(self, testdir, monkeypatch):
+        monkeypatch.delenv('PYTHONDONTWRITEBYTECODE', False)
+
+        search_path = []
+        for dirname in "hello", "world":
+            d = testdir.mkdir(dirname)
+            search_path.append(d)
+            ns = d.mkdir("ns_pkg")
+            ns.join("__init__.py").write(
+                "__import__('pkg_resources').declare_namespace(__name__)")
+            lib = ns.mkdir(dirname)
+            lib.ensure("__init__.py")
+            lib.join("test_{0}.py".format(dirname)). \
+                write("def test_{0}(): pass\n"
+                      "def test_other():pass".format(dirname))
+
+        # The structure of the test directory is now:
+        # .
+        # ├── hello
+        # │   └── ns_pkg
+        # │       ├── __init__.py
+        # │       └── hello
+        # │           ├── __init__.py
+        # │           └── test_hello.py
+        # └── world
+        #     └── ns_pkg
+        #         ├── __init__.py
+        #         └── world
+        #             ├── __init__.py
+        #             └── test_world.py
+
+        def join_pythonpath(*dirs):
+            cur = py.std.os.environ.get('PYTHONPATH')
+            if cur:
+                dirs += (cur,)
+            return ':'.join(str(p) for p in dirs)
+        monkeypatch.setenv('PYTHONPATH', join_pythonpath(*search_path))
+        for p in search_path:
+            monkeypatch.syspath_prepend(p)
+
+        # mixed module and filenames:
+        result = testdir.runpytest("--pyargs", "ns_pkg.hello", "world/ns_pkg")
+        assert result.ret == 0
+        result.stdout.fnmatch_lines([
+            "*4 passed*"
+        ])
+
+        # specify tests within a module
+        result = testdir.runpytest("--pyargs", "ns_pkg.world.test_world::test_other")
+        assert result.ret == 0
+        result.stdout.fnmatch_lines([
+            "*1 passed*"
+        ])
+
+        # namespace package
+        result = testdir.runpytest("--pyargs", "ns_pkg")
+        assert result.ret
+        result.stderr.fnmatch_lines([
+            "ERROR:*Cannot*uniquely*resolve*package*directory:*ns_pkg",
+        ])
+
     def test_cmdline_python_package_not_exists(self, testdir):
         result = testdir.runpytest("--pyargs", "tpkgwhatv")
         assert result.ret
@@ -697,4 +759,3 @@ def test_setup_function(self, testdir):
             * setup *test_1*
             * call *test_1*
         """)
-