Mockito，如何在方法中創建的 object 上調用驗證？

Question

簡單示例：

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    HttpServletRequest req = (HttpServletRequest) request;
    HttpServletResponse res = (HttpServletResponse) response;
    res.addCookie(cookie);
    chain.doFilter(request, response);
}

如果 object 是從 ServletResponse 創建的，我如何驗證是否在 HttpServletResponse object 上調用了 addCoockie 方法。

Answer 1

將HttpServletResponse的模擬傳遞給過濾器，然后對其進行驗證。

我們需要測試的自定義過濾器

import javax.servlet.*;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class CustomFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse res = (HttpServletResponse) response;
        res.addCookie(new Cookie("name", "value")); // filter call addCookie method which need to be verified
        filterChain.doFilter(request, response);
    }

    @Override
    public void destroy() {

    }
}

測試實施

import org.junit.jupiter.api.Test;

import javax.servlet.FilterChain;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import static org.mockito.Mockito.*;

public class FilterTest {
    CustomFilter customFilter = new CustomFilter();

    @Test
    public void testDoFilter() throws Exception {
        HttpServletRequest request = mock(HttpServletRequest.class);
        //create mock of HttpServletResponse object
        HttpServletResponse response = mock(HttpServletResponse.class);
        FilterChain filterChain = mock(FilterChain.class);

        //pass HttpServletResponse object to the filter
        customFilter.doFilter(request, response, filterChain);

        //verify that addCookie method was executed with correct value
        verify(response, times(1)).addCookie(argThat(cookie -> "name".equals(cookie.getName()) && "value".equals(cookie.getValue())));
    }
}