Add acceptance tests for new :net_http_connect_on_start allowed values

spec/acceptance/net_http/net_http_spec.rb

@@ -254,6 +254,21 @@ class TestMarshalingInWebMockNetHTTP
         }
       end
 
+      it "should connect to the server on start when allowlisted", net_connect: true do
+        WebMock.disable_net_connect!(allow: "www.google.com", net_http_connect_on_start: "www.google.com")
+        @http.start {|conn|
+          cert = OpenSSL::X509::Certificate.new conn.peer_cert
+          expect(cert).to be_a(OpenSSL::X509::Certificate)
+        }
+      end
+
+      it "should not connect to the server on start when not allowlisted", net_connect: true do
+        WebMock.disable_net_connect!(allow: "www.google.com", net_http_connect_on_start: "www.yahoo.com")
+        @http.start {|conn|
+          expect(conn.peer_cert).to be_nil
+        }
+      end
+
       it "should connect to the server if the URI matches an regex", net_connect: true do
         WebMock.disable_net_connect!(allow: /google.com/)
         Net::HTTP.get('www.google.com','/')
@@ -282,6 +297,13 @@ class TestMarshalingInWebMockNetHTTP
     it_should_behave_like "Net::HTTP"
   end
 
+  describe "when net_http_connect_on_start is a specific host" do
+    before(:each) do
+      WebMock.allow_net_connect!(net_http_connect_on_start: "localhost")
+    end
+    it_should_behave_like "Net::HTTP"
+  end
+
   describe 'after_request callback support', net_connect: true do
     let(:expected_body_regex) { /hello world/ }