diff --git a/.gitignore b/.gitignore
index c2d2a72090e..fcbd92e97a3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,7 +4,6 @@
 *.egg
 !/tests/**/*.egg
 /*.egg-info
-/tests/fixtures/**/*.egg-info
 /dist/*
 build
 _build
diff --git a/poetry/puzzle/provider.py b/poetry/puzzle/provider.py
index 989a592912b..4888b9828b1 100644
--- a/poetry/puzzle/provider.py
+++ b/poetry/puzzle/provider.py
@@ -326,10 +326,7 @@ def get_package_from_directory(
             os.chdir(str(directory))
 
             try:
-                with temporary_directory() as tmp_dir:
-                    EnvManager.build_venv(tmp_dir)
-                    venv = VirtualEnv(Path(tmp_dir), Path(tmp_dir))
-                    venv.run("python", "setup.py", "egg_info")
+                cls._execute_setup()
             except EnvCommandError:
                 result = SetupReader.read_from_directory(directory)
                 if not result["name"]:
@@ -817,3 +814,9 @@ def progress(self):
                 yield
 
         self._in_progress = False
+
+    def _execute_setup(self):
+        with temporary_directory() as tmp_dir:
+            EnvManager.build_venv(tmp_dir)
+            venv = VirtualEnv(Path(tmp_dir), Path(tmp_dir))
+            venv.run("python", "setup.py", "egg_info")
diff --git a/pyproject.toml b/pyproject.toml
index 938b89fe422..519fb373ca6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -116,3 +116,23 @@ known_third_party = [
     "shellingham",
     "tomlkit",
 ]
+
+
+[tool.black]
+line-length = 88
+include = '\.pyi?$'
+exclude = '''
+/(
+    \.eggs
+  | \.git
+  | \.hg
+  | \.mypy_cache
+  | \.tox
+  | \.venv
+  | _build
+  | buck-out
+  | build
+  | dist
+  | tests/.*/setup.py
+)/
+'''
diff --git a/tests/conftest.py b/tests/conftest.py
index d5ff7f488c9..8386ad35f57 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -74,6 +74,11 @@ def download_mock(mocker):
     mocker.patch("poetry.utils.inspector.Inspector.download", new=mock_download)
 
 
+@pytest.fixture(autouse=True)
+def execute_setup_mock(mocker):
+    mocker.patch("poetry.puzzle.provider.Provider._execute_setup")
+
+
 @pytest.fixture
 def environ():
     original_environ = dict(os.environ)
diff --git a/tests/fixtures/git/github.com/demo/demo/demo.egg-info/PKG-INFO b/tests/fixtures/git/github.com/demo/demo/demo.egg-info/PKG-INFO
new file mode 100755
index 00000000000..7f543c49cb3
--- /dev/null
+++ b/tests/fixtures/git/github.com/demo/demo/demo.egg-info/PKG-INFO
@@ -0,0 +1,12 @@
+Metadata-Version: 2.1
+Name: demo
+Version: 0.1.2
+Summary: Demo project.
+Home-page: https://github.com/demo/demo
+Author: Sébastien Eustace
+Author-email: sebastien@eustace.io
+License: MIT
+Description: UNKNOWN
+Platform: UNKNOWN
+Provides-Extra: bar
+Provides-Extra: foo
diff --git a/tests/fixtures/git/github.com/demo/demo/demo.egg-info/SOURCES.txt b/tests/fixtures/git/github.com/demo/demo/demo.egg-info/SOURCES.txt
new file mode 100755
index 00000000000..6eb8a3ef3e3
--- /dev/null
+++ b/tests/fixtures/git/github.com/demo/demo/demo.egg-info/SOURCES.txt
@@ -0,0 +1,7 @@
+setup.py
+demo/__init__.py
+demo.egg-info/PKG-INFO
+demo.egg-info/SOURCES.txt
+demo.egg-info/dependency_links.txt
+demo.egg-info/requires.txt
+demo.egg-info/top_level.txt
diff --git a/tests/fixtures/git/github.com/demo/demo/demo.egg-info/dependency_links.txt b/tests/fixtures/git/github.com/demo/demo/demo.egg-info/dependency_links.txt
new file mode 100755
index 00000000000..e69de29bb2d
diff --git a/tests/fixtures/git/github.com/demo/demo/demo.egg-info/requires.txt b/tests/fixtures/git/github.com/demo/demo/demo.egg-info/requires.txt
new file mode 100755
index 00000000000..e05a65d3c93
--- /dev/null
+++ b/tests/fixtures/git/github.com/demo/demo/demo.egg-info/requires.txt
@@ -0,0 +1,7 @@
+pendulum>=1.4.4
+
+[bar]
+tomlkit
+
+[foo]
+cleo
diff --git a/tests/fixtures/git/github.com/demo/demo/demo.egg-info/top_level.txt b/tests/fixtures/git/github.com/demo/demo/demo.egg-info/top_level.txt
new file mode 100755
index 00000000000..1549b67ca59
--- /dev/null
+++ b/tests/fixtures/git/github.com/demo/demo/demo.egg-info/top_level.txt
@@ -0,0 +1 @@
+demo
diff --git a/tests/fixtures/git/github.com/demo/no-dependencies/demo.egg-info/PKG-INFO b/tests/fixtures/git/github.com/demo/no-dependencies/demo.egg-info/PKG-INFO
new file mode 100644
index 00000000000..7ba97897a10
--- /dev/null
+++ b/tests/fixtures/git/github.com/demo/no-dependencies/demo.egg-info/PKG-INFO
@@ -0,0 +1,10 @@
+Metadata-Version: 1.0
+Name: demo
+Version: 0.1.2
+Summary: Demo project.
+Home-page: https://github.com/demo/demo
+Author: Sébastien Eustace
+Author-email: sebastien@eustace.io
+License: MIT
+Description: UNKNOWN
+Platform: UNKNOWN
diff --git a/tests/fixtures/git/github.com/demo/no-dependencies/demo.egg-info/SOURCES.txt b/tests/fixtures/git/github.com/demo/no-dependencies/demo.egg-info/SOURCES.txt
new file mode 100644
index 00000000000..e19f4a4eb57
--- /dev/null
+++ b/tests/fixtures/git/github.com/demo/no-dependencies/demo.egg-info/SOURCES.txt
@@ -0,0 +1,6 @@
+setup.py
+demo/__init__.py
+demo.egg-info/PKG-INFO
+demo.egg-info/SOURCES.txt
+demo.egg-info/dependency_links.txt
+demo.egg-info/top_level.txt
diff --git a/tests/fixtures/git/github.com/demo/no-dependencies/demo.egg-info/dependency_links.txt b/tests/fixtures/git/github.com/demo/no-dependencies/demo.egg-info/dependency_links.txt
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/fixtures/git/github.com/demo/no-dependencies/demo.egg-info/top_level.txt b/tests/fixtures/git/github.com/demo/no-dependencies/demo.egg-info/top_level.txt
new file mode 100644
index 00000000000..1549b67ca59
--- /dev/null
+++ b/tests/fixtures/git/github.com/demo/no-dependencies/demo.egg-info/top_level.txt
@@ -0,0 +1 @@
+demo
diff --git a/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/PKG-INFO b/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/PKG-INFO
new file mode 100644
index 00000000000..996589ec257
--- /dev/null
+++ b/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/PKG-INFO
@@ -0,0 +1,12 @@
+Metadata-Version: 2.1
+Name: Demo
+Version: 0.1.2
+Summary: Demo project.
+Home-page: https://github.com/demo/demo
+Author: Sébastien Eustace
+Author-email: sebastien@eustace.io
+License: MIT
+Description: UNKNOWN
+Platform: UNKNOWN
+Provides-Extra: foo
+Provides-Extra: bar
diff --git a/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/SOURCES.txt b/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/SOURCES.txt
new file mode 100644
index 00000000000..8134b008da5
--- /dev/null
+++ b/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/SOURCES.txt
@@ -0,0 +1,7 @@
+setup.py
+Demo.egg-info/PKG-INFO
+Demo.egg-info/SOURCES.txt
+Demo.egg-info/dependency_links.txt
+Demo.egg-info/requires.txt
+Demo.egg-info/top_level.txt
+demo/__init__.py
diff --git a/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/dependency_links.txt b/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/dependency_links.txt
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/requires.txt b/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/requires.txt
new file mode 100644
index 00000000000..e05a65d3c93
--- /dev/null
+++ b/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/requires.txt
@@ -0,0 +1,7 @@
+pendulum>=1.4.4
+
+[bar]
+tomlkit
+
+[foo]
+cleo
diff --git a/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/top_level.txt b/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/top_level.txt
new file mode 100644
index 00000000000..1549b67ca59
--- /dev/null
+++ b/tests/fixtures/git/github.com/demo/non-canonical-name/Demo.egg-info/top_level.txt
@@ -0,0 +1 @@
+demo
diff --git a/tests/fixtures/project_with_setup/my_package.egg-info/PKG-INFO b/tests/fixtures/project_with_setup/my_package.egg-info/PKG-INFO
new file mode 100644
index 00000000000..71ba645751f
--- /dev/null
+++ b/tests/fixtures/project_with_setup/my_package.egg-info/PKG-INFO
@@ -0,0 +1,10 @@
+Metadata-Version: 1.0
+Name: my-package
+Version: 0.1.2
+Summary: Demo project.
+Home-page: https://github.com/demo/demo
+Author: Sébastien Eustace
+Author-email: sebastien@eustace.io
+License: MIT
+Description: UNKNOWN
+Platform: UNKNOWN
diff --git a/tests/fixtures/project_with_setup/my_package.egg-info/SOURCES.txt b/tests/fixtures/project_with_setup/my_package.egg-info/SOURCES.txt
new file mode 100644
index 00000000000..f5255dc9dad
--- /dev/null
+++ b/tests/fixtures/project_with_setup/my_package.egg-info/SOURCES.txt
@@ -0,0 +1,7 @@
+setup.py
+my_package/__init__.py
+my_package.egg-info/PKG-INFO
+my_package.egg-info/SOURCES.txt
+my_package.egg-info/dependency_links.txt
+my_package.egg-info/requires.txt
+my_package.egg-info/top_level.txt
diff --git a/tests/fixtures/project_with_setup/my_package.egg-info/dependency_links.txt b/tests/fixtures/project_with_setup/my_package.egg-info/dependency_links.txt
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/fixtures/project_with_setup/my_package.egg-info/requires.txt b/tests/fixtures/project_with_setup/my_package.egg-info/requires.txt
new file mode 100644
index 00000000000..eeb0a4815ce
--- /dev/null
+++ b/tests/fixtures/project_with_setup/my_package.egg-info/requires.txt
@@ -0,0 +1,2 @@
+pendulum>=1.4.4
+cachy[msgpack]>=0.2.0
diff --git a/tests/fixtures/project_with_setup/my_package.egg-info/top_level.txt b/tests/fixtures/project_with_setup/my_package.egg-info/top_level.txt
new file mode 100644
index 00000000000..5d04b540bc9
--- /dev/null
+++ b/tests/fixtures/project_with_setup/my_package.egg-info/top_level.txt
@@ -0,0 +1 @@
+my_package
diff --git a/tests/masonry/builders/fixtures/excluded_subpackage/README.rst b/tests/masonry/builders/fixtures/excluded_subpackage/README.rst
index b00640203c5..f7fe15470f9 100644
--- a/tests/masonry/builders/fixtures/excluded_subpackage/README.rst
+++ b/tests/masonry/builders/fixtures/excluded_subpackage/README.rst
@@ -1,2 +1,2 @@
 My Package
-==========
\ No newline at end of file
+==========
diff --git a/tests/puzzle/test_provider.py b/tests/puzzle/test_provider.py
index d3bcba65688..4d4463b3b73 100644
--- a/tests/puzzle/test_provider.py
+++ b/tests/puzzle/test_provider.py
@@ -118,7 +118,7 @@ def test_search_for_vcs_read_setup_with_extras(provider, mocker):
 
 def test_search_for_vcs_read_setup_raises_error_if_no_version(provider, mocker):
     mocker.patch(
-        "poetry.utils.env.VirtualEnv.run",
+        "poetry.puzzle.provider.Provider._execute_setup",
         side_effect=EnvCommandError(CalledProcessError(1, "python", output="")),
     )
 
diff --git a/tests/repositories/fixtures/installed/vendor/py3.7/attrs-19.3.0.dist-info/METADATA b/tests/repositories/fixtures/installed/vendor/py3.7/attrs-19.3.0.dist-info/METADATA
index a1064151030..6c8d9f7d6eb 100644
--- a/tests/repositories/fixtures/installed/vendor/py3.7/attrs-19.3.0.dist-info/METADATA
+++ b/tests/repositories/fixtures/installed/vendor/py3.7/attrs-19.3.0.dist-info/METADATA
@@ -225,5 +225,3 @@ A full list of contributors can be found in `GitHub's overview <https://github.c
 
 It’s the spiritual successor of `characteristic <https://characteristic.readthedocs.io/>`_ and aspires to fix some of it clunkiness and unfortunate decisions.
 Both were inspired by Twisted’s `FancyEqMixin <https://twistedmatrix.com/documents/current/api/twisted.python.util.FancyEqMixin.html>`_ but both are implemented using class decorators because `subclassing is bad for you <https://www.youtube.com/watch?v=3MNVP9-hglc>`_, m’kay?
-
-