Discover Python files in dirs without __init__.py. Fixes #790

also renames the module b/c there's another checker which will
fit in here

kiwi_lint/__init__.py

@@ -11,7 +11,8 @@
 from .bulk_create import BulkCreateChecker
 from .objects_update import ObjectsUpdateChecker
 from .tags import TagsChecker
-from .empty_module import EmptyModuleChecker
+from .empty import EmptyModuleChecker
+from .empty import ModuleInDirectoryWithoutInitChecker
 from .nested_definition import NestedDefinitionChecker
 from .missing_permissions import MissingPermissionsChecker
 
@@ -26,5 +27,6 @@ def register(linter):
     linter.register_checker(ObjectsUpdateChecker(linter))
     linter.register_checker(TagsChecker(linter))
     linter.register_checker(EmptyModuleChecker(linter))
+    linter.register_checker(ModuleInDirectoryWithoutInitChecker(linter))
     linter.register_checker(NestedDefinitionChecker(linter))
     linter.register_checker(MissingPermissionsChecker(linter))

kiwi_lint/empty.py

@@ -0,0 +1,75 @@
+# Copyright (c) 2018 Alexander Todorov <[email protected]>
+
+# Licensed under the GPL 2.0: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+
+import os
+
+from pylint import interfaces
+from pylint import checkers
+from pylint.checkers import utils
+
+
+class EmptyModuleChecker(checkers.BaseChecker):
+    __implements__ = (interfaces.IAstroidChecker,)
+
+    name = 'empty-module-checker'
+
+    msgs = {'E4481': ("Remove empty module from git!",
+                      'remove-empty-module',
+                      "Kiwi TCMS doesn't need to carry around modules which are empty. "
+                      "They must be removed from the source code!")}
+
+    @utils.check_messages('remove-empty-module')
+    def visit_module(self, node):
+        if not node.body and not node.path[0].endswith('__init__.py'):
+            self.add_message('remove-empty-module', node=node)
+
+
+class ModuleInDirectoryWithoutInitChecker(checkers.BaseChecker):
+    __implements__ = (interfaces.IAstroidChecker,)
+
+    name = 'dir-without-init-checker'
+
+    msgs = {'R4482': ("File '%s' is in directory without __init__.py",
+                      'module-in-directory-without-init',
+                      "Python module is found inside a directory which is "
+                      "missing __init__.py! This will lead to missing packages when "
+                      "tarball is built for distribution on PyPI! See "
+                      "https://github.com/kiwitcms/Kiwi/issues/790")}
+
+    project_root = os.path.abspath(
+        os.path.join(os.path.dirname(__file__), '..', 'tcms'))
+
+    # NOTE: this works against tcms/ directory and will not take into account
+    # if we want to examine only a sub-dir or a few files
+    # all files found by os.walk
+    all_python_files = set()
+    # all modules found by pylint, which conveniently skips files/dirs
+    # with missing __init__.py
+    discovered_python_files = set()
+
+    def open(self):
+        for root, _dirs, files in os.walk(self.project_root, topdown=False):
+            # skip migrations
+            if root.find('migrations') > -1:
+                continue
+
+            for file_name in files:
+                if file_name.endswith('.py'):
+                    self.all_python_files.add(
+                        os.path.join(self.project_root, root, file_name))
+
+    def visit_module(self, node):
+        for file_name in node.path:
+            self.discovered_python_files.add(file_name)
+
+    @utils.check_messages('module-in-directory-without-init')
+    def close(self):
+        diff = self.all_python_files - self.discovered_python_files
+        diff = list(diff)
+        diff.sort()
+
+        dir_prefix = os.path.dirname(self.project_root) + '/'
+        for fname in diff:
+            fname = fname.replace(dir_prefix, '')
+            self.add_message('module-in-directory-without-init', args=(fname,))