MockMvc for HTTP assertions in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to perform a GET request using MockMvc.

Spring Boot

mockMvc.perform([1]("/api/data"))

Drag options to blanks, or click blank then click option'

Adelete

Bpost

Cput

Dget

Attempts:

3 left

💡 Hint

Common Mistakes

Using post instead of get for fetching data.

Confusing HTTP methods.

The get method is used to perform a GET request in MockMvc.

2fill in blank

medium

Complete the code to expect a 200 OK status in the response.

Spring Boot

mockMvc.perform(get("/api/data")).andExpect([1].status().isOk())

Drag options to blanks, or click blank then click option'

AMockMvcResultMatchers

BResultActions

CMockMvcBuilders

DMvcResult

Attempts:

3 left

💡 Hint

Common Mistakes

Using ResultActions instead of MockMvcResultMatchers.

Trying to assert status without the correct matcher.

MockMvcResultMatchers provides methods to assert the response status and content.

3fill in blank

hard

Fix the error in the code to check the response content contains 'success'.

Spring Boot

mockMvc.perform(get("/api/data")).andExpect(MockMvcResultMatchers.content().string([1]("success")))

Drag options to blanks, or click blank then click option'

Acontains

BcontainsString

ChasString

DstringContains

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect method names like 'contains' or 'hasString'.

Confusing with other matcher libraries.

The method containsString is used to check if the response content includes a specific substring.

4fill in blank

hard

Fill both blanks to perform a POST request with JSON content and expect a 201 status.

Spring Boot

mockMvc.perform([1]("/api/create").contentType([2]).content(jsonData)).andExpect(MockMvcResultMatchers.status().isCreated())

Drag options to blanks, or click blank then click option'

Apost

BMediaType.APPLICATION_JSON

CMediaType.TEXT_PLAIN

Dget

Attempts:

3 left

💡 Hint

Common Mistakes

Using GET instead of POST for creating data.

Wrong content type like TEXT_PLAIN.

Use post to send data and MediaType.APPLICATION_JSON to specify JSON content type.

5fill in blank

hard

Fill both blanks to check JSON response field 'name' equals 'John'.

Spring Boot

mockMvc.perform(get("/api/user/1")).andExpect(MockMvcResultMatchers.jsonPath([1]).value([2]))

Drag options to blanks, or click blank then click option'

A"$.name"

B"John"

C"$.id"

D"1"

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong JSON path like '$.id' for the name field.

Not quoting string values properly.

The JSON path "$.name" targets the 'name' field, and "John" is the expected value.

Practice

1. What is the main purpose of using MockMvc in Spring Boot tests?

easy

A. To test HTTP requests and responses without starting a real server

B. To deploy the application to a production server

C. To generate HTML pages automatically

D. To manage database connections

Solution

1. Step 1: Understand MockMvc role

   MockMvc simulates HTTP requests and responses in tests without needing a real server.

2. Step 2: Compare options

   Options A, B, and D describe unrelated tasks like HTML generation, deployment, or database management.

3. Final Answer:

   To test HTTP requests and responses without starting a real server -> Option A

4. Quick Check:

   MockMvc = HTTP testing without server [OK]

Hint: MockMvc tests HTTP calls without running the server [OK]

Common Mistakes:

• Thinking MockMvc starts a real server
• Confusing MockMvc with deployment tools
• Assuming MockMvc manages databases

2. Which of the following is the correct way to perform a GET request using MockMvc?

easy

A. mockMvc.perform(get("/api/data"))

B. mockMvc.get("/api/data")

C. mockMvc.request("GET", "/api/data")

D. mockMvc.callGet("/api/data")

Solution

1. Step 1: Recall MockMvc syntax

   The correct syntax uses mockMvc.perform(get("/url")) with static import of get.

2. Step 2: Check other options

   Options B, C, and D use invalid method names not provided by MockMvc API.

3. Final Answer:

   mockMvc.perform(get("/api/data")) -> Option A

4. Quick Check:

   Use perform(get()) for GET requests [OK]

Hint: Use perform(get("url")) to send GET requests [OK]

Common Mistakes:

• Using mockMvc.get() directly
• Confusing method names like request() or callGet()
• Not importing static get() method

3. Given the following test snippet, what HTTP status code will be asserted?

mockMvc.perform(get("/hello"))
       .andExpect(status().isOk());

medium

A. 404 Not Found

B. 500 Internal Server Error

C. 200 OK

D. 302 Redirect

Solution

1. Step 1: Understand status().isOk()

   The method status().isOk() checks for HTTP status code 200.

2. Step 2: Match status codes

   200 means success, 404 means not found, 500 means server error, 302 means redirect.

3. Final Answer:

   200 OK -> Option C

4. Quick Check:

   status().isOk() = 200 OK [OK]

Hint: isOk() always means HTTP 200 success [OK]

Common Mistakes:

• Confusing isOk() with error codes
• Assuming isOk() means redirect
• Mixing status codes meanings

4. Identify the error in this MockMvc test code snippet:

mockMvc.perform(post("/submit"))
       .andExpect(status().isOk)
       .andExpect(content().string("Success"));

medium

A. Using post instead of get for /submit

B. Missing parentheses after isOk method call

C. Incorrect content matcher method name

D. No error, code is correct

Solution

1. Step 1: Check method calls

   The method isOk must be called with parentheses: isOk().

2. Step 2: Verify other parts

   Using post for /submit is valid; content().string() is correct; so no other errors.

3. Final Answer:

   Missing parentheses after isOk method call -> Option B

4. Quick Check:

   Method calls need parentheses like isOk() [OK]

Hint: Always add () after status check methods like isOk() [OK]

Common Mistakes:

• Forgetting parentheses on isOk()
• Confusing post and get methods
• Using wrong content matcher method

5. You want to test a JSON response from /user/1 endpoint that returns {"name":"Alice","age":30}. Which MockMvc assertion correctly checks the name field in the JSON response?

hard

A. andExpect(content().string("Alice"))

B. andExpect(content().json("name: Alice"))

C. andExpect(jsonPath("name").isEqualTo("Alice"))

D. andExpect(jsonPath("$.name").value("Alice"))

Solution

1. Step 1: Understand JSON path syntax

   To check JSON fields, use jsonPath("$.fieldName") with value() for expected value.

2. Step 2: Evaluate options

   andExpect(jsonPath("$.name").value("Alice")) uses correct syntax. andExpect(content().json("name: Alice")) has invalid JSON format. andExpect(jsonPath("name").isEqualTo("Alice")) uses wrong jsonPath syntax. andExpect(content().string("Alice")) checks whole string, not JSON field.

3. Final Answer:

   andExpect(jsonPath("$.name").value("Alice")) -> Option D

4. Quick Check:

   Use jsonPath("$.field").value() for JSON checks [OK]

Hint: Use jsonPath("$.field").value(expected) to check JSON fields [OK]

Common Mistakes:

• Wrong jsonPath syntax without $
• Trying to match JSON with plain string
• Using incorrect matcher methods