Use local server for an unit test for lazy wheel

tests/unit/test_network_lazy_wheel.py

@@ -8,7 +8,7 @@
     dist_from_wheel_url,
 )
 from pip._internal.network.session import PipSession
-from tests.lib.requests_mocks import MockResponse
+from tests.lib.server import file_response
 
 MYPY_0_782_WHL = (
     'https://files.pythonhosted.org/packages/9d/65/'
@@ -28,6 +28,16 @@ def session():
     return PipSession()
 
 
+@fixture
+def mypy_whl_no_range(mock_server, shared_data):
+    mypy_whl = shared_data.packages / 'mypy-0.782-py3-none-any.whl'
+    mock_server.set_responses([file_response(mypy_whl)])
+    mock_server.start()
+    base_address = 'http://{}:{}'.format(mock_server.host, mock_server.port)
+    yield "{}/{}".format(base_address, 'mypy-0.782-py3-none-any.whl')
+    mock_server.stop()
+
+
 @mark.network
 def test_dist_from_wheel_url(session):
     """Test if the acquired distribution contain correct information."""
@@ -38,12 +48,10 @@ def test_dist_from_wheel_url(session):
     assert set(dist.requires(dist.extras)) == MYPY_0_782_REQS
 
 
-@mark.network
-def test_dist_from_wheel_url_no_range(session, monkeypatch):
+def test_dist_from_wheel_url_no_range(session, mypy_whl_no_range):
     """Test handling when HTTP range requests are not supported."""
-    monkeypatch.setattr(session, 'head', lambda *a, **kw: MockResponse(b''))
     with raises(HTTPRangeRequestUnsupported):
-        dist_from_wheel_url('mypy', MYPY_0_782_WHL, session)
+        dist_from_wheel_url('mypy', mypy_whl_no_range, session)
 
 
 @mark.network