Implement our own version of `resource_filename`.

2 files changed, 42 insertions, 0 deletions

diff --git a/src/pyramid/path.py b/src/pyramid/path.py
index d4909d412..5138344c7 100644
--- a/src/pyramid/path.py
+++ b/src/pyramid/path.py
@@ -1,4 +1,8 @@
+import atexit
+from contextlib import ExitStack
+import functools
 from importlib.machinery import SOURCE_SUFFIXES
+import importlib.resources
 import os
 import pkg_resources
 import sys
@@ -9,6 +13,30 @@ from pyramid.interfaces import IAssetDescriptor
 init_names = ['__init__%s' % x for x in SOURCE_SUFFIXES]
 
 
+@functools.lru_cache(maxsize=None)
+def resource_filename(package, name):
+    """
+    Return a filename on the filesystem for the given resource.  If the
+    resource does not exist in the filesystem (e.g. in a zipped egg), it will
+    be extracted to a temporary directory and cleaned up when the application
+    exits.
+
+    This function is equivalent to the now-deprecated
+    ``pkg_resources.resource_filename``.
+
+    This function is only included in order to provide legacy functionality;
+    use should be avoided.  Instead prefer to use ``importlib.resource`` APIs
+    directly.
+
+    """
+    ref = importlib.resources.files(package) / name
+
+    manager = ExitStack()
+    atexit.register(manager.close)
+    path = manager.enter_context(importlib.resources.as_file(ref))
+    return str(path)
+
+
 def caller_path(path, level=2):
     if not os.path.isabs(path):
         module = caller_module(level + 1)
diff --git a/tests/test_path.py b/tests/test_path.py
index af3dfb500..968739af4 100644
--- a/tests/test_path.py
+++ b/tests/test_path.py
@@ -4,6 +4,20 @@ import unittest
 here = os.path.abspath(os.path.dirname(__file__))
 
 
+class TestResourceFilename(unittest.TestCase):
+    def _callFUT(self, package, name):
+        from pyramid.path import resource_filename
+
+        return resource_filename(package, name)
+
+    def test_returns_path(self):
+        path = self._callFUT('tests', 'test_path.py')
+        self.assertIsInstance(path, str)
+        # If it's a real path, we should be able to open and read from it.
+        with open(path) as fh:
+            assert fh.read(1)
+
+
 class TestCallerPath(unittest.TestCase):
     def tearDown(self):
         from . import test_path