test: drop pkg_resources tests dependency on easy_install

pkg_resources/tests/data/my-test-package-source/setup.py

+import setuptools
+setuptools.setup(
+    name="my-test-package",
+    version="1.0",
+    zip_safe=True,
+)

pkg_resources/tests/data/my-test-package_unpacked-egg/my_test_package-1.0-py3.7.egg/EGG-INFO/PKG-INFO

+Metadata-Version: 1.0
+Name: my-test-package
+Version: 1.0
+Summary: UNKNOWN
+Home-page: UNKNOWN
+Author: UNKNOWN
+Author-email: UNKNOWN
+License: UNKNOWN
+Description: UNKNOWN
+Platform: UNKNOWN

pkg_resources/tests/data/my-test-package_unpacked-egg/my_test_package-1.0-py3.7.egg/EGG-INFO/SOURCES.txt

+setup.cfg
+setup.py
+my_test_package.egg-info/PKG-INFO
+my_test_package.egg-info/SOURCES.txt
+my_test_package.egg-info/dependency_links.txt
+my_test_package.egg-info/top_level.txt
+my_test_package.egg-info/zip-safe
\ No newline at end of file

pkg_resources/tests/data/my-test-package_unpacked-egg/my_test_package-1.0-py3.7.egg/EGG-INFO/dependency_links.txt

+

pkg_resources/tests/data/my-test-package_unpacked-egg/my_test_package-1.0-py3.7.egg/EGG-INFO/top_level.txt

+

pkg_resources/tests/data/my-test-package_unpacked-egg/my_test_package-1.0-py3.7.egg/EGG-INFO/zip-safe

+

pkg_resources/tests/test_find_distributions.py

-import subprocess
-import sys
-
+import py
 import pytest
 import pkg_resources
 
-SETUP_TEMPLATE = """
-import setuptools
-setuptools.setup(
-    name="my-test-package",
-    version="1.0",
-    zip_safe=True,
-)
-""".lstrip()
+
+TESTS_DATA_DIR = py.path.local(__file__).dirpath('data')
 
 
 class TestFindDistributions:
@@ -21,46 +13,22 @@ class TestFindDistributions:
         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)
+        return target_dir
 
     def test_non_egg_dir_named_egg(self, target_dir):
-        dists = pkg_resources.find_distributions(target_dir)
+        dists = pkg_resources.find_distributions(str(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)
+    def test_standalone_egg_directory(self, target_dir):
+        (TESTS_DATA_DIR / 'my-test-package_unpacked-egg').copy(target_dir)
+        dists = pkg_resources.find_distributions(str(target_dir))
         assert [dist.project_name for dist in dists] == ['my-test-package']
-        dists = pkg_resources.find_distributions(target_dir, only=True)
+        dists = pkg_resources.find_distributions(str(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)
+    def test_zipped_egg(self, target_dir):
+        (TESTS_DATA_DIR / 'my-test-package_zipped-egg').copy(target_dir)
+        dists = pkg_resources.find_distributions(str(target_dir))
         assert [dist.project_name for dist in dists] == ['my-test-package']
-        dists = pkg_resources.find_distributions(target_dir, only=True)
+        dists = pkg_resources.find_distributions(str(target_dir), only=True)
         assert not list(dists)

pytest.ini

 [pytest]
 addopts=--doctest-modules --doctest-glob=pkg_resources/api_tests.txt -r sxX
-norecursedirs=dist build *.egg setuptools/extern pkg_resources/extern tools .*
+norecursedirs=dist build *.egg setuptools/extern pkg_resources/extern pkg_resources/tests/data tools .*
 flake8-ignore =
     setuptools/site-patch.py F821
     setuptools/py*compat.py F811