Better detect unpacked eggs

Do not assume a directory named in `.egg` is an egg, unless it has an
actual egg metadata directory.

Closes #462

1 files changed, 65 insertions, 0 deletions

diff --git a/pkg_resources/tests/test_find_distributions.py b/pkg_resources/tests/test_find_distributions.py
new file mode 100644
index 00000000..97999b33
--- /dev/null
+++ b/pkg_resources/tests/test_find_distributions.py
@@ -0,0 +1,65 @@
+import subprocess
+import sys
+
+import pytest
+import pkg_resources
+
+SETUP_TEMPLATE = """
+import setuptools
+setuptools.setup(
+    name="my-test-package",
+    version="1.0",
+    zip_safe=True,
+)
+""".lstrip()
+
+class TestFindDistributions:
+
+    @pytest.fixture
+    def target_dir(self, tmpdir):
+        target_dir = tmpdir.mkdir('target')
+        # place a .egg named directory in the target that is not an egg:
+        target_dir.mkdir('not.an.egg')
+        return str(target_dir)
+
+    @pytest.fixture
+    def project_dir(self, tmpdir):
+        project_dir = tmpdir.mkdir('my-test-package')
+        (project_dir / "setup.py").write(SETUP_TEMPLATE)
+        return str(project_dir)
+
+    def test_non_egg_dir_named_egg(self, target_dir):
+        dists = pkg_resources.find_distributions(target_dir)
+        assert not list(dists)
+
+    def test_standalone_egg_directory(self, project_dir, target_dir):
+        # install this distro as an unpacked egg:
+        args = [
+            sys.executable,
+            '-c', 'from setuptools.command.easy_install import main; main()',
+            '-mNx',
+            '-d', target_dir,
+            '--always-unzip',
+            project_dir,
+        ]
+        subprocess.check_call(args)
+        dists = pkg_resources.find_distributions(target_dir)
+        assert [dist.project_name for dist in dists] == ['my-test-package']
+        dists = pkg_resources.find_distributions(target_dir, only=True)
+        assert not list(dists)
+
+    def test_zipped_egg(self, project_dir, target_dir):
+        # install this distro as an unpacked egg:
+        args = [
+            sys.executable,
+            '-c', 'from setuptools.command.easy_install import main; main()',
+            '-mNx',
+            '-d', target_dir,
+            '--zip-ok',
+            project_dir,
+        ]
+        subprocess.check_call(args)
+        dists = pkg_resources.find_distributions(target_dir)
+        assert [dist.project_name for dist in dists] == ['my-test-package']
+        dists = pkg_resources.find_distributions(target_dir, only=True)
+        assert not list(dists)