Restoring authorship annotation for <say@yandex-team.ru>. Commit 2 of 2.

3 files changed, 539 insertions, 539 deletions

diff --git a/library/python/runtime_py3/importer.pxi b/library/python/runtime_py3/importer.pxi
index 8d8b523d4c..904f94dea2 100644
--- a/library/python/runtime_py3/importer.pxi
+++ b/library/python/runtime_py3/importer.pxi
@@ -2,7 +2,7 @@ import marshal
 import sys
 from _codecs import utf_8_decode, utf_8_encode
 from _frozen_importlib import _call_with_frames_removed, spec_from_loader, BuiltinImporter
-from _frozen_importlib_external import _os, _path_isfile, _path_isdir, _path_isabs, path_sep, _path_join, _path_split 
+from _frozen_importlib_external import _os, _path_isfile, _path_isdir, _path_isabs, path_sep, _path_join, _path_split
 from _io import FileIO
 
 import __res as __resource
@@ -11,9 +11,9 @@ _b = lambda x: x if isinstance(x, bytes) else utf_8_encode(x)[0]
 _s = lambda x: x if isinstance(x, str) else utf_8_decode(x)[0]
 env_entry_point = b'Y_PYTHON_ENTRY_POINT'
 env_source_root = b'Y_PYTHON_SOURCE_ROOT'
-cfg_source_root = b'arcadia-source-root' 
-env_extended_source_search = b'Y_PYTHON_EXTENDED_SOURCE_SEARCH' 
-res_ya_ide_venv = b'YA_IDE_VENV' 
+cfg_source_root = b'arcadia-source-root'
+env_extended_source_search = b'Y_PYTHON_EXTENDED_SOURCE_SEARCH'
+res_ya_ide_venv = b'YA_IDE_VENV'
 executable = sys.executable or 'Y_PYTHON'
 sys.modules['run_import_hook'] = __resource
 
@@ -21,59 +21,59 @@ sys.modules['run_import_hook'] = __resource
 py_prefix = b'py/'
 py_prefix_len = len(py_prefix)
 
-YA_IDE_VENV = __resource.find(res_ya_ide_venv) 
-Y_PYTHON_EXTENDED_SOURCE_SEARCH = _os.environ.get(env_extended_source_search) or YA_IDE_VENV 
-
-
-def _init_venv(): 
-    if not _path_isabs(executable): 
-        raise RuntimeError('path in sys.executable is not absolute: {}'.format(executable)) 
- 
-    # Creative copy-paste from site.py 
-    exe_dir, _ = _path_split(executable) 
-    site_prefix, _ = _path_split(exe_dir) 
-    libpath = _path_join(site_prefix, 'lib', 
-                           'python%d.%d' % sys.version_info[:2], 
-                           'site-packages') 
-    sys.path.insert(0, libpath) 
- 
-    # emulate site.venv() 
-    sys.prefix = site_prefix 
-    sys.exec_prefix = site_prefix 
- 
-    conf_basename = 'pyvenv.cfg' 
-    candidate_confs = [ 
-        conffile for conffile in ( 
-            _path_join(exe_dir, conf_basename), 
-            _path_join(site_prefix, conf_basename) 
-            ) 
-        if _path_isfile(conffile) 
-        ] 
-    if not candidate_confs: 
-        raise RuntimeError('{} not found'.format(conf_basename)) 
-    virtual_conf = candidate_confs[0] 
-    with FileIO(virtual_conf, 'r') as f: 
-        for line in f: 
-            if b'=' in line: 
-                key, _, value = line.partition(b'=') 
-                key = key.strip().lower() 
-                value = value.strip() 
-                if key == cfg_source_root: 
-                    return value 
-    raise RuntimeError('{} key not found in {}'.format(cfg_source_root, virtual_conf)) 
- 
- 
-def _get_source_root(): 
-    env_value = _os.environ.get(env_source_root) 
-    if env_value or not YA_IDE_VENV: 
-        return env_value 
- 
-    return _init_venv() 
- 
- 
-Y_PYTHON_SOURCE_ROOT = _get_source_root() 
- 
- 
+YA_IDE_VENV = __resource.find(res_ya_ide_venv)
+Y_PYTHON_EXTENDED_SOURCE_SEARCH = _os.environ.get(env_extended_source_search) or YA_IDE_VENV
+
+
+def _init_venv():
+    if not _path_isabs(executable):
+        raise RuntimeError('path in sys.executable is not absolute: {}'.format(executable))
+
+    # Creative copy-paste from site.py
+    exe_dir, _ = _path_split(executable)
+    site_prefix, _ = _path_split(exe_dir)
+    libpath = _path_join(site_prefix, 'lib',
+                           'python%d.%d' % sys.version_info[:2],
+                           'site-packages')
+    sys.path.insert(0, libpath)
+
+    # emulate site.venv()
+    sys.prefix = site_prefix
+    sys.exec_prefix = site_prefix
+
+    conf_basename = 'pyvenv.cfg'
+    candidate_confs = [
+        conffile for conffile in (
+            _path_join(exe_dir, conf_basename),
+            _path_join(site_prefix, conf_basename)
+            )
+        if _path_isfile(conffile)
+        ]
+    if not candidate_confs:
+        raise RuntimeError('{} not found'.format(conf_basename))
+    virtual_conf = candidate_confs[0]
+    with FileIO(virtual_conf, 'r') as f:
+        for line in f:
+            if b'=' in line:
+                key, _, value = line.partition(b'=')
+                key = key.strip().lower()
+                value = value.strip()
+                if key == cfg_source_root:
+                    return value
+    raise RuntimeError('{} key not found in {}'.format(cfg_source_root, virtual_conf))
+
+
+def _get_source_root():
+    env_value = _os.environ.get(env_source_root)
+    if env_value or not YA_IDE_VENV:
+        return env_value
+
+    return _init_venv()
+
+
+Y_PYTHON_SOURCE_ROOT = _get_source_root()
+
+
 def _print(*xs):
     """
     This is helpful for debugging, since automatic bytes to str conversion is
@@ -181,10 +181,10 @@ class ResourceImporter(object):
         self.source_map = {}                  # Map from file names to module names.
         self._source_name = {}                # Map from original to altered module names.
         self._package_prefix = ''
-        if Y_PYTHON_SOURCE_ROOT and Y_PYTHON_EXTENDED_SOURCE_SEARCH: 
-            self.arcadia_source_finder = ArcadiaSourceFinder(_s(Y_PYTHON_SOURCE_ROOT)) 
-        else: 
-            self.arcadia_source_finder = None 
+        if Y_PYTHON_SOURCE_ROOT and Y_PYTHON_EXTENDED_SOURCE_SEARCH:
+            self.arcadia_source_finder = ArcadiaSourceFinder(_s(Y_PYTHON_SOURCE_ROOT))
+        else:
+            self.arcadia_source_finder = None
 
         for p in list(self.memory) + list(sys.builtin_module_names):
             for pp in iter_prefixes(p):
@@ -198,13 +198,13 @@ class ResourceImporter(object):
         importer._package_prefix = name + '.'
         return importer
 
-    def _find_mod_path(self, fullname): 
-        """Find arcadia relative path by module name""" 
-        relpath = resfs_src(mod_path(fullname), resfs_file=True) 
-        if relpath or not self.arcadia_source_finder: 
-            return relpath 
-        return self.arcadia_source_finder.get_module_path(fullname) 
- 
+    def _find_mod_path(self, fullname):
+        """Find arcadia relative path by module name"""
+        relpath = resfs_src(mod_path(fullname), resfs_file=True)
+        if relpath or not self.arcadia_source_finder:
+            return relpath
+        return self.arcadia_source_finder.get_module_path(fullname)
+
     def find_spec(self, fullname, path=None, target=None):
         try:
             is_package = self.is_package(fullname)
@@ -245,7 +245,7 @@ class ResourceImporter(object):
         modname = fullname
         if self.is_package(fullname):
             fullname += '.__init__'
-        relpath = self._find_mod_path(fullname) 
+        relpath = self._find_mod_path(fullname)
         if isinstance(relpath, bytes):
             relpath = _s(relpath)
         return relpath or modname
@@ -272,7 +272,7 @@ class ResourceImporter(object):
             fullname += '.__init__'
 
         path = mod_path(fullname)
-        relpath = self._find_mod_path(fullname) 
+        relpath = self._find_mod_path(fullname)
         if relpath:
             abspath = resfs_resolve(relpath)
             if abspath:
@@ -298,9 +298,9 @@ class ResourceImporter(object):
         if fullname + '.__init__' in self.memory:
             return True
 
-        if self.arcadia_source_finder: 
-            return self.arcadia_source_finder.is_package(fullname) 
- 
+        if self.arcadia_source_finder:
+            return self.arcadia_source_finder.is_package(fullname)
+
         raise ImportError(fullname)
 
     # Extension for contrib/python/coverage.
@@ -329,9 +329,9 @@ class ResourceImporter(object):
             m = rx.match(p)
             if m:
                 yield prefix + m.group(1), m.group(2) is not None
-        if self.arcadia_source_finder: 
-            for m in self.arcadia_source_finder.iter_modules(self._package_prefix, prefix): 
-                yield m 
+        if self.arcadia_source_finder:
+            for m in self.arcadia_source_finder.iter_modules(self._package_prefix, prefix):
+                yield m
 
     def get_resource_reader(self, fullname):
         try:
@@ -394,134 +394,134 @@ class BuiltinSubmoduleImporter(BuiltinImporter):
             return None
 
 
-class ArcadiaSourceFinder: 
-    """ 
-        Search modules and packages in arcadia source tree. 
-        See https://wiki.yandex-team.ru/devtools/extended-python-source-search/ for details 
-    """ 
-    NAMESPACE_PREFIX = b'py/namespace/' 
-    PY_EXT = '.py' 
-    YA_MAKE = 'ya.make' 
- 
-    def __init__(self, source_root): 
-        self.source_root = source_root 
-        self.module_path_cache = {'': set()} 
-        for key, dirty_path in iter_keys(self.NAMESPACE_PREFIX): 
-            # dirty_path contains unique prefix to prevent repeatable keys in the resource storage 
-            path = dirty_path.split(b'/', 1)[1] 
-            namespaces = __resource.find(key).split(b':') 
-            for n in namespaces: 
-                package_name = _s(n.rstrip(b'.')) 
-                self.module_path_cache.setdefault(package_name, set()).add(_s(path)) 
-                # Fill parents with default empty path set if parent doesn't exist in the cache yet 
-                while package_name: 
-                    package_name = package_name.rpartition('.')[0] 
-                    if package_name in self.module_path_cache: 
-                        break 
-                    self.module_path_cache.setdefault(package_name, set()) 
-        for package_name in self.module_path_cache.keys(): 
-            self._add_parent_dirs(package_name, visited=set()) 
- 
-    def get_module_path(self, fullname): 
-        """ 
-            Find file path for module 'fullname'. 
-            For packages caller pass fullname as 'package.__init__'. 
-            Return None if nothing is found. 
-        """ 
-        try: 
-            if not self.is_package(fullname): 
-                return _b(self._cache_module_path(fullname)) 
-        except ImportError: 
-            pass 
- 
-    def is_package(self, fullname): 
-        """Check if fullname is a package. Raise ImportError if fullname is not found""" 
-        path = self._cache_module_path(fullname) 
-        if isinstance(path, set): 
-            return True 
-        if isinstance(path, str): 
-            return False 
-        raise ImportError(fullname) 
- 
-    def iter_modules(self, package_prefix, prefix): 
-        paths = self._cache_module_path(package_prefix.rstrip('.')) 
-        if paths is not None: 
-            # Note: it's ok to yield duplicates because pkgutil discards them 
- 
-            # Yield from cache 
-            import re 
-            rx = re.compile(re.escape(package_prefix) + r'([^.]+)$') 
-            for mod, path in self.module_path_cache.items(): 
-                if path is not None: 
-                    m = rx.match(mod) 
-                    if m: 
-                        yield prefix + m.group(1), self.is_package(mod) 
- 
-            # Yield from file system 
-            for path in paths: 
-                abs_path = _path_join(self.source_root, path) 
-                for dir_item in _os.listdir(abs_path): 
-                    if self._path_is_simple_dir(_path_join(abs_path, dir_item)): 
-                        yield prefix  +  dir_item, True 
-                    elif dir_item.endswith(self.PY_EXT) and _path_isfile(_path_join(abs_path, dir_item)): 
-                        yield prefix + dir_item[:-len(self.PY_EXT)], False 
- 
-    def _path_is_simple_dir(self, abs_path): 
-        """ 
-            Check if path is a directory but doesn't contain ya.make file. 
-            We don't want to steal directory from nested project and treat it as a package 
-        """ 
-        return _path_isdir(abs_path) and not _path_isfile(_path_join(abs_path, self.YA_MAKE)) 
- 
-    def _find_module_in_paths(self, find_package_only, paths, module): 
-        """Auxiliary method. See _cache_module_path() for details""" 
-        if paths: 
-            package_paths = set() 
-            for path in paths: 
-                rel_path = _path_join(path, module) 
-                if not find_package_only: 
-                    # Check if file_path is a module 
-                    module_path = rel_path + self.PY_EXT 
-                    if _path_isfile(_path_join(self.source_root, module_path)): 
-                        return module_path 
-                # Check if file_path is a package 
-                if self._path_is_simple_dir(_path_join(self.source_root, rel_path)): 
-                    package_paths.add(rel_path) 
-            if package_paths: 
-                return package_paths 
- 
-    def _cache_module_path(self, fullname, find_package_only=False): 
-        """  
-            Find module path or package directory paths and save result in the cache 
- 
-            find_package_only=True - don't try to find module 
- 
-            Returns: 
-               List of relative package paths - for a package 
-               Relative module path - for a module 
-               None - module or package is not found 
+class ArcadiaSourceFinder:
+    """
+        Search modules and packages in arcadia source tree.
+        See https://wiki.yandex-team.ru/devtools/extended-python-source-search/ for details
+    """
+    NAMESPACE_PREFIX = b'py/namespace/'
+    PY_EXT = '.py'
+    YA_MAKE = 'ya.make'
+
+    def __init__(self, source_root):
+        self.source_root = source_root
+        self.module_path_cache = {'': set()}
+        for key, dirty_path in iter_keys(self.NAMESPACE_PREFIX):
+            # dirty_path contains unique prefix to prevent repeatable keys in the resource storage
+            path = dirty_path.split(b'/', 1)[1]
+            namespaces = __resource.find(key).split(b':')
+            for n in namespaces:
+                package_name = _s(n.rstrip(b'.'))
+                self.module_path_cache.setdefault(package_name, set()).add(_s(path))
+                # Fill parents with default empty path set if parent doesn't exist in the cache yet
+                while package_name:
+                    package_name = package_name.rpartition('.')[0]
+                    if package_name in self.module_path_cache:
+                        break
+                    self.module_path_cache.setdefault(package_name, set())
+        for package_name in self.module_path_cache.keys():
+            self._add_parent_dirs(package_name, visited=set())
+
+    def get_module_path(self, fullname):
+        """
+            Find file path for module 'fullname'.
+            For packages caller pass fullname as 'package.__init__'.
+            Return None if nothing is found.
+        """
+        try:
+            if not self.is_package(fullname):
+                return _b(self._cache_module_path(fullname))
+        except ImportError:
+            pass
+
+    def is_package(self, fullname):
+        """Check if fullname is a package. Raise ImportError if fullname is not found"""
+        path = self._cache_module_path(fullname)
+        if isinstance(path, set):
+            return True
+        if isinstance(path, str):
+            return False
+        raise ImportError(fullname)
+
+    def iter_modules(self, package_prefix, prefix):
+        paths = self._cache_module_path(package_prefix.rstrip('.'))
+        if paths is not None:
+            # Note: it's ok to yield duplicates because pkgutil discards them
+
+            # Yield from cache
+            import re
+            rx = re.compile(re.escape(package_prefix) + r'([^.]+)$')
+            for mod, path in self.module_path_cache.items():
+                if path is not None:
+                    m = rx.match(mod)
+                    if m:
+                        yield prefix + m.group(1), self.is_package(mod)
+
+            # Yield from file system
+            for path in paths:
+                abs_path = _path_join(self.source_root, path)
+                for dir_item in _os.listdir(abs_path):
+                    if self._path_is_simple_dir(_path_join(abs_path, dir_item)):
+                        yield prefix  +  dir_item, True
+                    elif dir_item.endswith(self.PY_EXT) and _path_isfile(_path_join(abs_path, dir_item)):
+                        yield prefix + dir_item[:-len(self.PY_EXT)], False
+
+    def _path_is_simple_dir(self, abs_path):
+        """
+            Check if path is a directory but doesn't contain ya.make file.
+            We don't want to steal directory from nested project and treat it as a package
+        """
+        return _path_isdir(abs_path) and not _path_isfile(_path_join(abs_path, self.YA_MAKE))
+
+    def _find_module_in_paths(self, find_package_only, paths, module):
+        """Auxiliary method. See _cache_module_path() for details"""
+        if paths:
+            package_paths = set()
+            for path in paths:
+                rel_path = _path_join(path, module)
+                if not find_package_only:
+                    # Check if file_path is a module
+                    module_path = rel_path + self.PY_EXT
+                    if _path_isfile(_path_join(self.source_root, module_path)):
+                        return module_path
+                # Check if file_path is a package
+                if self._path_is_simple_dir(_path_join(self.source_root, rel_path)):
+                    package_paths.add(rel_path)
+            if package_paths:
+                return package_paths
+
+    def _cache_module_path(self, fullname, find_package_only=False):
         """ 
-        if fullname not in self.module_path_cache: 
-            parent, _, tail = fullname.rpartition('.') 
-            parent_paths = self._cache_module_path(parent, find_package_only=True) 
-            self.module_path_cache[fullname] = self._find_module_in_paths(find_package_only, parent_paths, tail) 
-        return self.module_path_cache[fullname] 
- 
-    def _add_parent_dirs(self, package_name, visited): 
-        if not package_name or package_name in visited: 
-            return 
-        visited.add(package_name) 
- 
-        parent, _, tail = package_name.rpartition('.') 
-        self._add_parent_dirs(parent, visited) 
- 
-        paths = self.module_path_cache[package_name] 
-        for parent_path in self.module_path_cache[parent]: 
-            rel_path = _path_join(parent_path, tail) 
-            if self._path_is_simple_dir(_path_join(self.source_root, rel_path)): 
-                paths.add(rel_path) 
- 
- 
+            Find module path or package directory paths and save result in the cache
+
+            find_package_only=True - don't try to find module
+
+            Returns:
+               List of relative package paths - for a package
+               Relative module path - for a module
+               None - module or package is not found
+        """
+        if fullname not in self.module_path_cache:
+            parent, _, tail = fullname.rpartition('.')
+            parent_paths = self._cache_module_path(parent, find_package_only=True)
+            self.module_path_cache[fullname] = self._find_module_in_paths(find_package_only, parent_paths, tail)
+        return self.module_path_cache[fullname]
+
+    def _add_parent_dirs(self, package_name, visited):
+        if not package_name or package_name in visited:
+            return
+        visited.add(package_name)
+
+        parent, _, tail = package_name.rpartition('.')
+        self._add_parent_dirs(parent, visited)
+
+        paths = self.module_path_cache[package_name]
+        for parent_path in self.module_path_cache[parent]:
+            rel_path = _path_join(parent_path, tail)
+            if self._path_is_simple_dir(_path_join(self.source_root, rel_path)):
+                paths.add(rel_path)
+
+
 def excepthook(*args, **kws):
     # traceback module cannot be imported at module level, because interpreter
     # is not fully initialized yet
@@ -544,19 +544,19 @@ def executable_path_hook(path):
     raise ImportError(path)
 
 
-if YA_IDE_VENV: 
-    sys.meta_path.append(importer) 
-    sys.meta_path.append(BuiltinSubmoduleImporter) 
-    if executable not in sys.path: 
-        sys.path.append(executable) 
-    sys.path_hooks.append(executable_path_hook) 
-else: 
-    sys.meta_path.insert(0, BuiltinSubmoduleImporter) 
-    sys.meta_path.insert(0, importer) 
-    if executable not in sys.path: 
-        sys.path.insert(0, executable) 
-    sys.path_hooks.insert(0, executable_path_hook) 
- 
+if YA_IDE_VENV:
+    sys.meta_path.append(importer)
+    sys.meta_path.append(BuiltinSubmoduleImporter)
+    if executable not in sys.path:
+        sys.path.append(executable)
+    sys.path_hooks.append(executable_path_hook)
+else:
+    sys.meta_path.insert(0, BuiltinSubmoduleImporter)
+    sys.meta_path.insert(0, importer)
+    if executable not in sys.path:
+        sys.path.insert(0, executable)
+    sys.path_hooks.insert(0, executable_path_hook)
+
 sys.path_importer_cache[executable] = importer
 
 # Indicator that modules and resources are built-in rather than on the file system.
diff --git a/library/python/runtime_py3/test/test_arcadia_source_finder.py b/library/python/runtime_py3/test/test_arcadia_source_finder.py
index b45f77a910..ff80d0a0a2 100644
--- a/library/python/runtime_py3/test/test_arcadia_source_finder.py
+++ b/library/python/runtime_py3/test/test_arcadia_source_finder.py
@@ -1,317 +1,317 @@
-import unittest 
-import yaml 
-from unittest.mock import patch 
-from parameterized import parameterized 
- 
-import __res as res 
- 
- 
-NAMESPACE_PREFIX = b'py/namespace/' 
-TEST_SOURCE_ROOT = '/home/arcadia' 
- 
- 
-class ImporterMocks(object): 
-    def __init__(self, mock_fs, mock_resources): 
-        self._mock_fs = mock_fs 
-        self._mock_resources = mock_resources 
-        self._patchers = [ 
-            patch('__res.iter_keys', wraps=self._iter_keys), 
-            patch('__res.__resource.find', wraps=self._resource_find), 
-            patch('__res._path_isdir', wraps=self._path_isdir), 
-            patch('__res._path_isfile', wraps=self._path_isfile), 
-            patch('__res._os.listdir', wraps=self._os_listdir), 
-        ] 
-        for patcher in self._patchers: 
-            patcher.start() 
- 
-    def stop(self): 
-        for patcher in self._patchers: 
-            patcher.stop() 
- 
-    def _iter_keys(self, prefix): 
-        assert prefix == NAMESPACE_PREFIX 
-        l = len(prefix) 
-        for k in self._mock_resources.keys(): 
-            yield k, k[l:] 
- 
-    def _resource_find(self, key): 
-        return self._mock_resources.get(key) 
- 
-    def _lookup_mock_fs(self, filename): 
-        path = filename.lstrip('/').split('/') 
-        curdir = self._mock_fs 
-        for item in path: 
-            if item in curdir: 
-                curdir = curdir[item] 
-            else: 
-                return None 
-        return curdir 
- 
-    def _path_isfile(self, filename): 
-        f = self._lookup_mock_fs(filename) 
-        return isinstance(f, str) 
- 
-    def _path_isdir(self, filename): 
-        f = self._lookup_mock_fs(filename) 
-        return isinstance(f, dict) 
- 
-    def _os_listdir(self, dirname): 
-        f = self._lookup_mock_fs(dirname) 
-        if isinstance(f, dict): 
-            return f.keys() 
-        else: 
-            return [] 
- 
- 
-class ArcadiaSourceFinderTestCase(unittest.TestCase): 
-    def setUp(self): 
-        self.import_mock = ImporterMocks(yaml.safe_load(self._get_mock_fs()), self._get_mock_resources()) 
-        self.arcadia_source_finder = res.ArcadiaSourceFinder(TEST_SOURCE_ROOT) 
- 
-    def tearDown(self): 
-        self.import_mock.stop() 
- 
-    def _get_mock_fs(self): 
-        raise NotImplementedError() 
- 
-    def _get_mock_resources(self): 
-        raise NotImplementedError() 
- 
- 
-class TestLibraryWithoutNamespace(ArcadiaSourceFinderTestCase): 
-    def _get_mock_fs(self): 
-        return ''' 
-           home: 
-             arcadia: 
-               project: 
-                 lib: 
-                   mod1.py: "" 
-                   package1: 
-                     mod2.py: "" 
-        ''' 
- 
-    def _get_mock_resources(self): 
-        return { 
-            b'py/namespace/unique_prefix1/project/lib': b'project.lib.', 
-        } 
- 
-    @parameterized.expand([ 
-        ('project.lib.mod1', b'project/lib/mod1.py'), 
-        ('project.lib.package1.mod2', b'project/lib/package1/mod2.py'), 
-        ('project.lib.unknown_module', None), 
-        ('project.lib', None),  # package 
-    ]) 
-    def test_get_module_path(self, module, path): 
-        assert path == self.arcadia_source_finder.get_module_path(module) 
- 
-    @parameterized.expand([ 
-        ('project.lib.mod1', False), 
-        ('project.lib.package1.mod2', False), 
-        ('project', True), 
-        ('project.lib', True), 
-        ('project.lib.package1', True), 
-    ]) 
-    def test_is_packages(self, module, is_package): 
-        assert is_package == self.arcadia_source_finder.is_package(module) 
- 
-    def test_is_package_for_unknown_module(self): 
-        self.assertRaises(ImportError, lambda: self.arcadia_source_finder.is_package('project.lib.package2')) 
- 
-    @parameterized.expand([ 
-        ('', { 
-            ('PFX.project', True), 
-        }), 
-        ('project.', { 
-            ('PFX.lib', True), 
-        }), 
-        ('project.lib.', { 
-            ('PFX.mod1', False), 
-            ('PFX.package1', True), 
-        }), 
-        ('project.lib.package1.', { 
-            ('PFX.mod2', False), 
-        }), 
-    ]) 
-    def test_iter_modules(self, package_prefix, expected): 
-        got = self.arcadia_source_finder.iter_modules(package_prefix, 'PFX.') 
-        assert expected == set(got) 
- 
-    # Check iter_modules() don't crash and return correct result after not existing module was requested 
-    def test_iter_modules_after_unknown_module_import(self): 
-        self.arcadia_source_finder.get_module_path('project.unknown_module') 
-        assert {('lib', True)} == set(self.arcadia_source_finder.iter_modules('project.', '')) 
- 
- 
-class TestLibraryExtendedFromAnotherLibrary(ArcadiaSourceFinderTestCase): 
-    def _get_mock_fs(self): 
-        return ''' 
-           home: 
-             arcadia: 
-               project: 
-                 lib: 
-                   mod1.py: '' 
-                 lib_extension: 
-                   mod2.py: '' 
-        ''' 
- 
-    def _get_mock_resources(self): 
-        return { 
-            b'py/namespace/unique_prefix1/project/lib': b'project.lib.', 
-            b'py/namespace/unique_prefix2/project/lib_extension': b'project.lib.', 
-        } 
- 
-    @parameterized.expand([ 
-        ('project.lib.mod1', b'project/lib/mod1.py'), 
-        ('project.lib.mod2', b'project/lib_extension/mod2.py'), 
-    ]) 
-    def test_get_module_path(self, module, path): 
-        assert path == self.arcadia_source_finder.get_module_path(module) 
- 
-    @parameterized.expand([ 
-        ('project.lib.', { 
-            ('PFX.mod1', False), 
-            ('PFX.mod2', False), 
-        }), 
-    ]) 
-    def test_iter_modules(self, package_prefix, expected): 
-        got = self.arcadia_source_finder.iter_modules(package_prefix, 'PFX.') 
-        assert expected == set(got) 
- 
- 
-class TestNamespaceAndTopLevelLibraries(ArcadiaSourceFinderTestCase): 
-    def _get_mock_fs(self): 
-        return ''' 
-           home: 
-             arcadia: 
-               project: 
-                 ns_lib: 
-                   mod1.py: '' 
-                 top_level_lib: 
-                   mod2.py: '' 
-        ''' 
- 
-    def _get_mock_resources(self): 
-        return { 
-            b'py/namespace/unique_prefix1/project/ns_lib': b'ns.', 
-            b'py/namespace/unique_prefix2/project/top_level_lib': b'.', 
-        } 
- 
-    @parameterized.expand([ 
-        ('ns.mod1', b'project/ns_lib/mod1.py'), 
-        ('mod2', b'project/top_level_lib/mod2.py'), 
-    ]) 
-    def test_get_module_path(self, module, path): 
-        assert path == self.arcadia_source_finder.get_module_path(module) 
- 
-    @parameterized.expand([ 
-        ('ns', True), 
-        ('ns.mod1', False), 
-        ('mod2', False), 
-    ]) 
-    def test_is_packages(self, module, is_package): 
-        assert is_package == self.arcadia_source_finder.is_package(module) 
- 
-    @parameterized.expand([ 
-        'project', 
-        'project.ns_lib', 
-        'project.top_level_lib', 
-    ]) 
-    def test_is_package_for_unknown_modules(self, module): 
-        self.assertRaises(ImportError, lambda: self.arcadia_source_finder.is_package(module)) 
- 
-    @parameterized.expand([ 
-        ('', { 
-            ('PFX.ns', True), 
-            ('PFX.mod2', False), 
-        }), 
-        ('ns.', { 
-            ('PFX.mod1', False), 
-        }), 
-    ]) 
-    def test_iter_modules(self, package_prefix, expected): 
-        got = self.arcadia_source_finder.iter_modules(package_prefix, 'PFX.') 
-        assert expected == set(got) 
- 
- 
-class TestIgnoreDirectoriesWithYaMakeFile(ArcadiaSourceFinderTestCase): 
-    ''' Packages and modules from tests should not be part of pylib namespace ''' 
-    def _get_mock_fs(self): 
-        return ''' 
-           home: 
-             arcadia: 
-               contrib: 
-                 python: 
-                   pylib: 
-                     mod1.py: "" 
-                     tests: 
-                       conftest.py: "" 
-                       ya.make: "" 
-        ''' 
- 
-    def _get_mock_resources(self): 
-        return { 
-            b'py/namespace/unique_prefix1/contrib/python/pylib': b'pylib.', 
-        } 
- 
-    def test_get_module_path_for_lib(self): 
-        assert b'contrib/python/pylib/mod1.py' == self.arcadia_source_finder.get_module_path('pylib.mod1') 
- 
-    def test_get_module_for_tests(self): 
-        assert self.arcadia_source_finder.get_module_path('pylib.tests.conftest') is None 
- 
-    def test_is_package_for_tests(self): 
-        self.assertRaises(ImportError, lambda: self.arcadia_source_finder.is_package('pylib.tests')) 
- 
- 
-class TestMergingNamespaceAndDirectoryPackages(ArcadiaSourceFinderTestCase): 
-    ''' Merge parent package (top level in this test) dirs with namespace dirs (DEVTOOLS-8979) ''' 
-    def _get_mock_fs(self): 
-        return ''' 
-           home: 
-             arcadia: 
-               contrib: 
-                 python: 
-                   pylint: 
-                     ya.make: "" 
-                     pylint: 
-                       __init__.py: "" 
-                     patcher: 
-                       patch.py: "" 
-                       ya.make: "" 
-        ''' 
- 
-    def _get_mock_resources(self): 
-        return { 
-            b'py/namespace/unique_prefix1/contrib/python/pylint': b'.', 
-            b'py/namespace/unique_prefix1/contrib/python/pylint/patcher': b'pylint.', 
-        } 
- 
-    @parameterized.expand([ 
-        ('pylint.__init__', b'contrib/python/pylint/pylint/__init__.py'), 
-        ('pylint.patch', b'contrib/python/pylint/patcher/patch.py'), 
-    ]) 
-    def test_get_module_path(self, module, path): 
-        assert path == self.arcadia_source_finder.get_module_path(module) 
- 
- 
-class TestEmptyResources(ArcadiaSourceFinderTestCase): 
-    def _get_mock_fs(self): 
-        return ''' 
-           home: 
-             arcadia: 
-               project: 
-                 lib: 
-                   mod1.py: '' 
-        ''' 
- 
-    def _get_mock_resources(self): 
-        return {} 
- 
-    def test_get_module_path(self): 
-        assert self.arcadia_source_finder.get_module_path('project.lib.mod1') is None 
- 
-    def test_is_package(self): 
-        self.assertRaises(ImportError, lambda: self.arcadia_source_finder.is_package('project')) 
- 
-    def test_iter_modules(self): 
-        assert [] == list(self.arcadia_source_finder.iter_modules('', 'PFX.')) 
+import unittest
+import yaml
+from unittest.mock import patch
+from parameterized import parameterized
+
+import __res as res
+
+
+NAMESPACE_PREFIX = b'py/namespace/'
+TEST_SOURCE_ROOT = '/home/arcadia'
+
+
+class ImporterMocks(object):
+    def __init__(self, mock_fs, mock_resources):
+        self._mock_fs = mock_fs
+        self._mock_resources = mock_resources
+        self._patchers = [
+            patch('__res.iter_keys', wraps=self._iter_keys),
+            patch('__res.__resource.find', wraps=self._resource_find),
+            patch('__res._path_isdir', wraps=self._path_isdir),
+            patch('__res._path_isfile', wraps=self._path_isfile),
+            patch('__res._os.listdir', wraps=self._os_listdir),
+        ]
+        for patcher in self._patchers:
+            patcher.start()
+
+    def stop(self):
+        for patcher in self._patchers:
+            patcher.stop()
+
+    def _iter_keys(self, prefix):
+        assert prefix == NAMESPACE_PREFIX
+        l = len(prefix)
+        for k in self._mock_resources.keys():
+            yield k, k[l:]
+
+    def _resource_find(self, key):
+        return self._mock_resources.get(key)
+
+    def _lookup_mock_fs(self, filename):
+        path = filename.lstrip('/').split('/')
+        curdir = self._mock_fs
+        for item in path:
+            if item in curdir:
+                curdir = curdir[item]
+            else:
+                return None
+        return curdir
+
+    def _path_isfile(self, filename):
+        f = self._lookup_mock_fs(filename)
+        return isinstance(f, str)
+
+    def _path_isdir(self, filename):
+        f = self._lookup_mock_fs(filename)
+        return isinstance(f, dict)
+
+    def _os_listdir(self, dirname):
+        f = self._lookup_mock_fs(dirname)
+        if isinstance(f, dict):
+            return f.keys()
+        else:
+            return []
+
+
+class ArcadiaSourceFinderTestCase(unittest.TestCase):
+    def setUp(self):
+        self.import_mock = ImporterMocks(yaml.safe_load(self._get_mock_fs()), self._get_mock_resources())
+        self.arcadia_source_finder = res.ArcadiaSourceFinder(TEST_SOURCE_ROOT)
+
+    def tearDown(self):
+        self.import_mock.stop()
+
+    def _get_mock_fs(self):
+        raise NotImplementedError()
+
+    def _get_mock_resources(self):
+        raise NotImplementedError()
+
+
+class TestLibraryWithoutNamespace(ArcadiaSourceFinderTestCase):
+    def _get_mock_fs(self):
+        return '''
+           home:
+             arcadia:
+               project:
+                 lib:
+                   mod1.py: ""
+                   package1:
+                     mod2.py: ""
+        '''
+
+    def _get_mock_resources(self):
+        return {
+            b'py/namespace/unique_prefix1/project/lib': b'project.lib.',
+        }
+
+    @parameterized.expand([
+        ('project.lib.mod1', b'project/lib/mod1.py'),
+        ('project.lib.package1.mod2', b'project/lib/package1/mod2.py'),
+        ('project.lib.unknown_module', None),
+        ('project.lib', None),  # package
+    ])
+    def test_get_module_path(self, module, path):
+        assert path == self.arcadia_source_finder.get_module_path(module)
+
+    @parameterized.expand([
+        ('project.lib.mod1', False),
+        ('project.lib.package1.mod2', False),
+        ('project', True),
+        ('project.lib', True),
+        ('project.lib.package1', True),
+    ])
+    def test_is_packages(self, module, is_package):
+        assert is_package == self.arcadia_source_finder.is_package(module)
+
+    def test_is_package_for_unknown_module(self):
+        self.assertRaises(ImportError, lambda: self.arcadia_source_finder.is_package('project.lib.package2'))
+
+    @parameterized.expand([
+        ('', {
+            ('PFX.project', True),
+        }),
+        ('project.', {
+            ('PFX.lib', True),
+        }),
+        ('project.lib.', {
+            ('PFX.mod1', False),
+            ('PFX.package1', True),
+        }),
+        ('project.lib.package1.', {
+            ('PFX.mod2', False),
+        }),
+    ])
+    def test_iter_modules(self, package_prefix, expected):
+        got = self.arcadia_source_finder.iter_modules(package_prefix, 'PFX.')
+        assert expected == set(got)
+
+    # Check iter_modules() don't crash and return correct result after not existing module was requested
+    def test_iter_modules_after_unknown_module_import(self):
+        self.arcadia_source_finder.get_module_path('project.unknown_module')
+        assert {('lib', True)} == set(self.arcadia_source_finder.iter_modules('project.', ''))
+
+
+class TestLibraryExtendedFromAnotherLibrary(ArcadiaSourceFinderTestCase):
+    def _get_mock_fs(self):
+        return '''
+           home:
+             arcadia:
+               project:
+                 lib:
+                   mod1.py: ''
+                 lib_extension:
+                   mod2.py: ''
+        '''
+
+    def _get_mock_resources(self):
+        return {
+            b'py/namespace/unique_prefix1/project/lib': b'project.lib.',
+            b'py/namespace/unique_prefix2/project/lib_extension': b'project.lib.',
+        }
+
+    @parameterized.expand([
+        ('project.lib.mod1', b'project/lib/mod1.py'),
+        ('project.lib.mod2', b'project/lib_extension/mod2.py'),
+    ])
+    def test_get_module_path(self, module, path):
+        assert path == self.arcadia_source_finder.get_module_path(module)
+
+    @parameterized.expand([
+        ('project.lib.', {
+            ('PFX.mod1', False),
+            ('PFX.mod2', False),
+        }),
+    ])
+    def test_iter_modules(self, package_prefix, expected):
+        got = self.arcadia_source_finder.iter_modules(package_prefix, 'PFX.')
+        assert expected == set(got)
+
+
+class TestNamespaceAndTopLevelLibraries(ArcadiaSourceFinderTestCase):
+    def _get_mock_fs(self):
+        return '''
+           home:
+             arcadia:
+               project:
+                 ns_lib:
+                   mod1.py: ''
+                 top_level_lib:
+                   mod2.py: ''
+        '''
+
+    def _get_mock_resources(self):
+        return {
+            b'py/namespace/unique_prefix1/project/ns_lib': b'ns.',
+            b'py/namespace/unique_prefix2/project/top_level_lib': b'.',
+        }
+
+    @parameterized.expand([
+        ('ns.mod1', b'project/ns_lib/mod1.py'),
+        ('mod2', b'project/top_level_lib/mod2.py'),
+    ])
+    def test_get_module_path(self, module, path):
+        assert path == self.arcadia_source_finder.get_module_path(module)
+
+    @parameterized.expand([
+        ('ns', True),
+        ('ns.mod1', False),
+        ('mod2', False),
+    ])
+    def test_is_packages(self, module, is_package):
+        assert is_package == self.arcadia_source_finder.is_package(module)
+
+    @parameterized.expand([
+        'project',
+        'project.ns_lib',
+        'project.top_level_lib',
+    ])
+    def test_is_package_for_unknown_modules(self, module):
+        self.assertRaises(ImportError, lambda: self.arcadia_source_finder.is_package(module))
+
+    @parameterized.expand([
+        ('', {
+            ('PFX.ns', True),
+            ('PFX.mod2', False),
+        }),
+        ('ns.', {
+            ('PFX.mod1', False),
+        }),
+    ])
+    def test_iter_modules(self, package_prefix, expected):
+        got = self.arcadia_source_finder.iter_modules(package_prefix, 'PFX.')
+        assert expected == set(got)
+
+
+class TestIgnoreDirectoriesWithYaMakeFile(ArcadiaSourceFinderTestCase):
+    ''' Packages and modules from tests should not be part of pylib namespace '''
+    def _get_mock_fs(self):
+        return '''
+           home:
+             arcadia:
+               contrib:
+                 python:
+                   pylib:
+                     mod1.py: ""
+                     tests:
+                       conftest.py: ""
+                       ya.make: ""
+        '''
+
+    def _get_mock_resources(self):
+        return {
+            b'py/namespace/unique_prefix1/contrib/python/pylib': b'pylib.',
+        }
+
+    def test_get_module_path_for_lib(self):
+        assert b'contrib/python/pylib/mod1.py' == self.arcadia_source_finder.get_module_path('pylib.mod1')
+
+    def test_get_module_for_tests(self):
+        assert self.arcadia_source_finder.get_module_path('pylib.tests.conftest') is None
+
+    def test_is_package_for_tests(self):
+        self.assertRaises(ImportError, lambda: self.arcadia_source_finder.is_package('pylib.tests'))
+
+
+class TestMergingNamespaceAndDirectoryPackages(ArcadiaSourceFinderTestCase):
+    ''' Merge parent package (top level in this test) dirs with namespace dirs (DEVTOOLS-8979) '''
+    def _get_mock_fs(self):
+        return '''
+           home:
+             arcadia:
+               contrib:
+                 python:
+                   pylint:
+                     ya.make: ""
+                     pylint:
+                       __init__.py: ""
+                     patcher:
+                       patch.py: ""
+                       ya.make: ""
+        '''
+
+    def _get_mock_resources(self):
+        return {
+            b'py/namespace/unique_prefix1/contrib/python/pylint': b'.',
+            b'py/namespace/unique_prefix1/contrib/python/pylint/patcher': b'pylint.',
+        }
+
+    @parameterized.expand([
+        ('pylint.__init__', b'contrib/python/pylint/pylint/__init__.py'),
+        ('pylint.patch', b'contrib/python/pylint/patcher/patch.py'),
+    ])
+    def test_get_module_path(self, module, path):
+        assert path == self.arcadia_source_finder.get_module_path(module)
+
+
+class TestEmptyResources(ArcadiaSourceFinderTestCase):
+    def _get_mock_fs(self):
+        return '''
+           home:
+             arcadia:
+               project:
+                 lib:
+                   mod1.py: ''
+        '''
+
+    def _get_mock_resources(self):
+        return {}
+
+    def test_get_module_path(self):
+        assert self.arcadia_source_finder.get_module_path('project.lib.mod1') is None
+
+    def test_is_package(self):
+        self.assertRaises(ImportError, lambda: self.arcadia_source_finder.is_package('project'))
+
+    def test_iter_modules(self):
+        assert [] == list(self.arcadia_source_finder.iter_modules('', 'PFX.'))
diff --git a/library/python/runtime_py3/test/ya.make b/library/python/runtime_py3/test/ya.make
index ed0c143080..4ec3db74f5 100644
--- a/library/python/runtime_py3/test/ya.make
+++ b/library/python/runtime_py3/test/ya.make
@@ -7,11 +7,11 @@ OWNER(
 
 DEPENDS(library/python/runtime_py3/test/traceback)
 
-PEERDIR( 
-    contrib/python/parameterized 
-    contrib/python/PyYAML 
-) 
- 
+PEERDIR(
+    contrib/python/parameterized
+    contrib/python/PyYAML
+)
+
 PY_SRCS(
     TOP_LEVEL
     resources/__init__.py
@@ -22,7 +22,7 @@ TEST_SRCS(
     test_metadata.py
     test_resources.py
     test_traceback.py
-    test_arcadia_source_finder.py 
+    test_arcadia_source_finder.py
 )
 
 RESOURCE_FILES(