test(python): add tests for script arguments

Author: akinomyoga

test/fixtures/python/bar.txt

@@ -45,3 +45,23 @@ def test_9(self, completion):
     )
     def test_bb(self, completion):
         assert "-bb" in completion
+
+    @pytest.mark.complete("python -m foo bar -p ", cwd="python")
+    def test_script_args_1(self, completion):
+        assert "bar.txt" in completion
+
+    @pytest.mark.complete("python -mfoo bar -p ", cwd="python")
+    def test_script_args_2(self, completion):
+        assert "bar.txt" in completion
+
+    @pytest.mark.complete("python -- foo ", cwd="python")
+    def test_script_args_3(self, completion):
+        assert "bar.txt" in completion
+
+    @pytest.mark.complete("python -- ", cwd="python")
+    def test_script_args_4(self, completion):
+        assert "bar.txt" not in completion
+
+    @pytest.mark.complete("python -W -mfoo ", cwd="python")
+    def test_script_args_5(self, completion):
+        assert "bar.txt" not in completion