[Serve] Unskipped tests in test_pipeline.py (ray-project#21484)

python/ray/serve/pipeline/tests/test_pipeline.py

@@ -88,39 +88,42 @@ def __call__(self, name: str):
     assert greeter.call("Theodore") == "Top of the morning Theodore!"
 
 
-@pytest.mark.skipif(sys.platform == "win32", reason="File handling.")
 @pytest.mark.parametrize("execution_mode", ALL_EXECUTION_MODES)
 @enable_local_execution_mode_only
 def test_class_constructor_not_called_until_deployed(execution_mode,
                                                      shared_ray_instance):
     """Constructor should only be called after .deploy()."""
 
-    with tempfile.NamedTemporaryFile("w") as tmp:
+    tmp = tempfile.NamedTemporaryFile("w+", suffix=".tmp", delete=False)
+    tmp.close()
 
-        @pipeline.step(execution_mode=execution_mode)
-        class FileWriter:
-            def __init__(self, tmpfile: str, msg: str):
-                with open(tmpfile, "w") as f:
-                    f.write(msg)
-                    f.flush()
+    @pipeline.step(execution_mode=execution_mode)
+    class FileWriter:
+        def __init__(self, tmpfile_name, msg: str):
+            with open(tmpfile_name, "w") as tmpfile:
+                tmpfile.write(msg)
+                tmpfile.flush()
+
+        def __call__(self, arg: str):
+            return arg
 
-            def __call__(self, arg: str):
-                return arg
+    msg = "hello"
 
-        msg = "hello"
+    def constructor_called():
+        with open(tmp.name, "r") as f:
+            ret = f.readline() == msg
+        return ret
 
-        def constructor_called():
-            with open(tmp.name, "r") as f:
-                return f.read() == msg
+    file_writer = FileWriter(tmp.name, msg)
+    assert not constructor_called()
 
-        file_writer = FileWriter(tmp.name, msg)
-        assert not constructor_called()
+    writer_pipeline = file_writer(pipeline.INPUT)
+    assert not constructor_called()
 
-        writer_pipeline = file_writer(pipeline.INPUT)
-        assert not constructor_called()
+    assert writer_pipeline.deploy().call("hi") == "hi"
+    assert constructor_called()
 
-        assert writer_pipeline.deploy().call("hi") == "hi"
-        assert constructor_called()
+    os.unlink(tmp.name)
 
 
 @pytest.mark.parametrize("execution_mode", ALL_EXECUTION_MODES)