使用MockMvc进行断言时能否添加自定义提示消息？

Absolutely! You can ditch those comments and attach meaningful failure messages directly to your MockMvc assertions—so when a test fails, you’ll get clear, context-rich feedback instead of having to dig through comments to figure out what went wrong.

Here are two clean approaches to do this: #

1. Wrap Assertions with JUnit Directly

Instead of relying on andExpect() alone, fetch the MvcResult first and use standard JUnit assertions with your custom message. This is straightforward and doesn’t require any helper methods:

// Test case 1: No request body should return Bad Request
MvcResult noBodyResult = mockMvc.perform(post("/postregistration"))
        .andReturn();
assertEquals(
    "未提交请求体，应返回Bad Request",
    HttpStatus.BAD_REQUEST.value(),
    noBodyResult.getResponse().getStatus()
);

// Test case 2: Valid request body should return OK
MvcResult validBodyResult = mockMvc.perform(
        post("/postregistration")
            .content(toJson(registrationDto))
            .contentType(MediaType.APPLICATION_JSON) // Don't forget this for JSON bodies!
    )
    .andReturn();
assertEquals(
    "已提交请求体，应返回OK",
    HttpStatus.OK.value(),
    validBodyResult.getResponse().getStatus()
);

2. Create a Reusable Custom ResultMatcher (For Fluent Chaining)

If you prefer to keep the clean MockMvc chain style, create a helper method that returns a custom ResultMatcher with your message. This keeps your test code concise and consistent across all test cases:

// Add this helper method to your test class (or a base test class for reuse)
private ResultMatcher statusIs(HttpStatus expectedStatus, String failureMessage) {
    return result -> {
        int actualStatus = result.getResponse().getStatus();
        assertEquals(
            failureMessage,
            expectedStatus.value(),
            actualStatus
        );
    };
}

// Now use it just like the built-in matchers
mockMvc.perform(post("/postregistration"))
        .andExpect(statusIs(HttpStatus.BAD_REQUEST, "未提交请求体，应返回Bad Request"));

mockMvc.perform(
        post("/postregistration")
            .content(toJson(registrationDto))
            .contentType(MediaType.APPLICATION_JSON)
    )
    .andExpect(statusIs(HttpStatus.OK, "已提交请求体，应返回OK"));

Why This Works Better Than Comments #

• Self-documenting code: The message is tied directly to the assertion logic, so it can’t get outdated or disconnected from what the test is actually checking.
• Clear failure feedback: When a test fails, JUnit will print your custom message right in the error output—no more guessing what the test was supposed to do.
• Cleaner test code: You eliminate clunky comments and keep all test intent within the executable code.

内容的提问来源于stack exchange，提问作者George Z.