MockMvc for HTTP assertions in Spring Boot - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this MockMvc test?

Given the following MockMvc test code, what will be the HTTP status returned by the test?

Spring Boot

mockMvc.perform(get("/api/items/5"))
       .andExpect(status().isOk())
       .andReturn();

A HTTP 500 Internal Server Error

B HTTP 404 Not Found

C HTTP 200 OK

D HTTP 302 Found (Redirect)

💡 Hint

The test expects the status to be OK, so the controller must return 200.

The test uses andExpect(status().isOk()), which means it expects a 200 OK response from the controller for the GET request to /api/items/5.

📝 Syntax

intermediate

Which MockMvc code snippet correctly asserts JSON content?

Select the option that correctly asserts the JSON response contains a field 'name' with value 'Book'.

A mockMvc.perform(get("/api/item/1")).andExpect(jsonPath("$.name").value("Book"));

B mockMvc.perform(get("/api/item/1")).andExpect(jsonPath("name").value("Book"));

C mockMvc.perform(get("/api/item/1")).andExpect(jsonPath("$.name").equals("Book"));

D mockMvc.perform(get("/api/item/1")).andExpect(jsonPath("$.name").is("Book"));

💡 Hint

Use jsonPath with the correct JSON path syntax and the value() matcher.

Option A uses the correct JSON path syntax '$.name' and the value() matcher to check the field value. Other options use invalid methods or incorrect JSON path.

🔧 Debug

advanced

Why does this MockMvc test fail with a 404 error?

This MockMvc test fails with HTTP 404 Not Found. What is the most likely cause? mockMvc.perform(get("/api/users/10")) .andExpect(status().isOk());

A The controller does not have a mapping for /api/users/10

B The MockMvc instance is not initialized

C The test is missing a content type header

D The test expects the wrong HTTP status

💡 Hint

404 means the URL was not found by the controller.

HTTP 404 means the requested URL is not mapped in the controller. The test fails because /api/users/10 is not handled by any controller method.

❓ state_output

advanced

What is the value of the response content after this MockMvc call?

Given this MockMvc call, what will be the exact response content string? var result = mockMvc.perform(get("/api/message")) .andExpect(status().isOk()) .andReturn(); String content = result.getResponse().getContentAsString();

A "<message>Hello World</message>"

B "Hello World"

C "{message: Hello World}"

D "{\"message\":\"Hello World\"}"

💡 Hint

The controller returns a JSON object with a message field.

The response content is a JSON string with escaped quotes: {"message":"Hello World"}. Option D matches the exact string including escaped quotes.

🧠 Conceptual

expert

Which statement about MockMvc and Spring Boot testing is true?

Choose the correct statement about using MockMvc for HTTP assertions in Spring Boot tests.

A MockMvc requires the application to be deployed on a real server to work.

B MockMvc can test controller endpoints without starting the full HTTP server.

C MockMvc automatically tests database integration without configuration.

D MockMvc can only test GET requests, not POST or PUT.

💡 Hint

MockMvc simulates HTTP requests inside the test environment.

MockMvc allows testing controller endpoints by simulating HTTP requests without starting the full server. It does not require a real server and supports all HTTP methods.