refactor: refactor error handling and response assertions

- Remove the assertion for the response status code being equal to `http.StatusInternalServerError`
- Add a defer statement to close the response body
- Add an assertion for the response status code being equal to `http.StatusInternalServerError`

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

timeout_test.go

@@ -130,7 +130,9 @@ func TestWriter_Status(t *testing.T) {
 
 	r.ServeHTTP(w, req)
 
-	assert.Equal(t, w.Result().StatusCode, http.StatusInternalServerError)
+	// Close the response body
+	defer w.Result().Body.Close()
+	assert.Equal(t, http.StatusInternalServerError, w.Result().StatusCode)
 	assert.Equal(t, strconv.Itoa(http.StatusInternalServerError), req.Header.Get("X-Status-Code-MW-Set"))
 }