Remove dependency on importlib_metadata for testing a 'local' package.

Author: jaraco

importlib_metadata/tests/fixtures.py

@@ -1,5 +1,6 @@
 from __future__ import unicode_literals
 
+import os
 import sys
 import shutil
 import tempfile
@@ -20,17 +21,41 @@
 __metaclass__ = type
 
 
+@contextlib.contextmanager
+def tempdir():
+    tmpdir = tempfile.mkdtemp()
+    sys.path[:0] = [tmpdir]
+    try:
+        yield pathlib.Path(tmpdir)
+    finally:
+        sys.path.remove(tmpdir)
+        shutil.rmtree(tmpdir)
+
+
+@contextlib.contextmanager
+def save_cwd():
+    orig = os.getcwd()
+    try:
+        yield
+    finally:
+        os.chdir(orig)
+
+
+@contextlib.contextmanager
+def tempdir_as_cwd():
+    with save_cwd():
+        with tempdir() as tmp:
+            os.chdir(str(tmp))
+            yield tmp
+
+
 class SiteDir:
     @staticmethod
     @contextlib.contextmanager
     def site_dir():
-        tmpdir = tempfile.mkdtemp()
-        sys.path[:0] = [tmpdir]
-        try:
-            yield pathlib.Path(tmpdir)
-        finally:
-            sys.path.remove(tmpdir)
-            shutil.rmtree(tmpdir)
+        with tempdir() as tmp:
+            sys.path[:0] = [str(tmp)]
+            yield tmp
 
     def setUp(self):
         self.fixtures = ExitStack()
@@ -102,6 +127,14 @@ def setUp(self):
         build_files(EggInfoPkg.files, prefix=self.site_dir)
 
 
+class LocalPackage:
+    def setUp(self):
+        self.fixtures = ExitStack()
+        self.addCleanup(self.fixtures.close)
+        self.fixtures.enter_context(tempdir_as_cwd())
+        build_files(EggInfoPkg.files)
+
+
 def build_files(file_defs, prefix=pathlib.Path()):
     """
     Build a set of files/directories, as described by the

importlib_metadata/tests/test_api.py

@@ -101,11 +101,6 @@ def test_files_dist_info(self):
     def test_files_egg_info(self):
         self._test_files(importlib_metadata.files('egginfo-pkg'))
 
-    # This will require its own fixture. Leave it for now.
-    def test_find_local(self):
-        dist = importlib_metadata.api.local_distribution()
-        assert dist.metadata['Name'] == 'importlib-metadata'
-
     def test_requires(self):
         deps = importlib_metadata.requires('egginfo-pkg')
         parsed = list(map(packaging.requirements.Requirement, deps))
@@ -151,3 +146,9 @@ def test_more_complex_deps_requires_text(self):
 
         assert deps == expected
         assert all(map(packaging.requirements.Requirement, deps))
+
+
+class LocalProjectTests(fixtures.LocalPackage, unittest.TestCase):
+    def test_find_local(self):
+        dist = importlib_metadata.api.local_distribution()
+        assert dist.metadata['Name'] == 'egginfo-pkg'