Wiremock Interview Questions

What is WireMock, and what is it used for?
Answer: WireMock is an open-source tool for creating mock servers that simulate HTTP responses for testing purposes.

How does WireMock work?
Answer: WireMock uses HTTP requests and responses to simulate real API behavior. It receives incoming HTTP requests, matches them to predefined request patterns, and returns corresponding responses.

How do you install and configure WireMock?
Answer: There are different ways to install and configure WireMock, but typically it involves downloading the JAR file and starting the WireMock server with command-line parameters or configuration files.

What are some common use cases for WireMock?
Answer: WireMock is commonly used for testing applications that rely on third-party APIs, as well as for testing distributed systems and microservices.

What is the difference between stubbing and mocking in WireMock?
Answer: In WireMock, stubbing refers to creating a mock server that simulates the behavior of a real server, while mocking refers to creating an object that simulates the behavior of a real object.

How do you create a basic mock server in WireMock?
Answer: To create a basic mock server, you need to define a request pattern and a corresponding response in a JSON file.

How do you create a dynamic response in WireMock?
Answer: You can create dynamic responses by using placeholders, variables, and response templates. Placeholders are placeholders in the response body that can be replaced with dynamic values, while variables can be used to store and reuse dynamic values. Response templates are predefined templates that generate dynamic responses based on a given context.

What are some best practices for using WireMock?
Answer: Some best practices include using descriptive request and response patterns, organizing mappings in separate files, and using placeholders and variables to create dynamic responses.

How do you use WireMock to test REST APIs?
Answer: To test a REST API using WireMock, you can define a set of request and response mappings that simulate the expected behavior of the API. You can then use a testing framework like JUnit to verify that your application behaves as expected.

How do you match request headers in WireMock?
Answer: You can match request headers using the header field in the request pattern. For example, {"headers": {"Accept": {"equalTo": "application/json"}}} would match any request with an Accept header equal to application/json.

How do you match query parameters in WireMock?
Answer: You can match query parameters using the queryParameters field in the request pattern. For example, {"queryParameters": {"foo": {"equalTo": "bar"}}} would match any request with a query parameter named foo equal to bar.

How do you match request bodies in WireMock?
Answer: You can match request bodies using the bodyPatterns field in the request pattern. For example, {"bodyPatterns": [{"contains": "foo"}]} would match any request with a body that contains the string foo.

How do you create custom matchers in WireMock?
Answer: You can create custom matchers by implementing the com.github.tomakehurst.wiremock.matching.RequestMatcher interface and registering the matcher with the WireMock server.

How do you use WireMock with Java?
Answer: You can use WireMock with Java by adding the WireMock dependency to your project and starting the server from your Java code.

How do you configure WireMock to handle HTTPS requests?
Answer: To configure WireMock to handle HTTPS requests, you need to generate a self-signed certificate and configure the WireMock server to use it.

How do you verify that a request was made to a mock server in WireMock?
Answer: You can use WireMock's verification API to check that a specific request was made to the mock server, and how many times it was made.

How do you create a global response template in WireMock?
Answer: You can create a global response template by defining it in a separate file and specifying the path to that file in the server configuration.

How do you configure WireMock to return different responses for different users?
Answer: You can use WireMock's request-matching and response-templating features to return different responses based on the user's identity or other properties.

How do you simulate a slow or unresponsive server in WireMock?
Answer: You can use WireMock's fixedDelay or randomDelay fields to introduce a delay in the response, simulating a slow or unresponsive server.

How do you configure WireMock to log incoming requests and responses?
Answer: You can enable WireMock's logging feature and specify the desired log level in the server configuration.

How do you configure WireMock to run in Docker?
Answer: You can create a Docker image of the WireMock server and run it as a Docker container.

How do you use WireMock to test SOAP APIs?
Answer: WireMock can be used to test SOAP APIs by simulating the expected behavior of the API based on the SOAP envelope and response.

How do you create a conditional response in WireMock?
Answer: You can create a conditional response by using a combination of request matching and response templating, and adding conditional logic to the response template.

How do you configure WireMock to handle CORS requests?
Answer: You can configure WireMock to handle CORS requests by adding the appropriate response headers to the response template.

How do you simulate a server error in WireMock?
Answer: You can use WireMock's status field to simulate a server error, such as returning a 500 status code.

How do you simulate network latency in WireMock?
Answer: You can use WireMock's fixedDelay or randomDelay fields to simulate network latency, introducing a delay in the response.

How do you create a fault-tolerant mock server in WireMock?
Answer: You can create a fault-tolerant mock server by implementing retry logic in the response template, retrying the request a certain number of times before returning an error.

How do you simulate a response timeout in WireMock?
Answer: You can use WireMock's fixedDelay or randomDelay fields to introduce a delay that exceeds the client's timeout threshold, simulating a response timeout.

How do you use WireMock to test authentication and authorization?
Answer: WireMock can be used to test authentication and authorization by simulating the expected behavior of the authentication and authorization API.

How do you create a stateful mock server in WireMock?
Answer: You can create a stateful mock server by storing state information in a database or other persistent storage, and using that information to generate dynamic responses.

How do you use WireMock to test WebSockets?
Answer: WireMock can be used to test WebSockets by simulating the expected behavior of the WebSocket API.

How do you configure WireMock to return binary data, such as images or video?
Answer: You can configure WireMock to return binary data by adding the data to the response body and setting the appropriate content-type header.

How do you configure WireMock to handle multipart requests?
Answer: You can configure WireMock to handle multipart requests by adding the appropriate request headers and parsing the request body accordingly.

How do you use WireMock to test client-side error handling?
Answer: You can use WireMock to simulate server errors and test client-side error handling by expecting and verifying that the client handles the error appropriately.

How do you configure WireMock to handle HTTP redirects?
Answer: You can configure WireMock to handle HTTP redirects by adding the appropriate response headers and status code to the response template.

How do you create a mock server that responds differently based on the query parameters in the request?
Answer: You can create a mock server that responds differently based on query parameters by using request matching and response templating to generate the appropriate response based on the query parameters.

How do you configure WireMock to handle cookies?
Answer: You can configure WireMock to handle cookies by adding the appropriate response headers and set-cookie headers to the response template.

How do you use WireMock to test asynchronous APIs?
Answer: You can use WireMock to test asynchronous APIs by simulating the expected behavior of the asynchronous API, including any expected delays or timeouts.

How do you use WireMock to test APIs with custom authentication schemes?
Answer: You can use WireMock to test APIs with custom authentication schemes by simulating the expected behavior of the authentication API and verifying that the API under test behaves correctly based on the authentication result.

How do you use WireMock to test APIs with complex data structures?
Answer: You can use WireMock to test APIs with complex data structures by generating realistic data using response templating and verifying that the API under test correctly handles the complex data.

How do you use WireMock to test APIs that require complex query parameters?
Answer: You can use WireMock to test APIs that require complex query parameters by generating realistic query parameter data using response templating and verifying that the API under test correctly handles the complex query parameters.

How do you use WireMock to test APIs with custom HTTP headers?
Answer: You can use WireMock to test APIs with custom HTTP headers by adding the appropriate request and response headers to the mock server and verifying that the API under test correctly handles the custom headers.

How do you use WireMock to test APIs with streaming responses?
Answer: You can use WireMock to test APIs with streaming responses by simulating the expected behavior of the streaming API and verifying that the API under test correctly handles the streaming data.

How do you configure WireMock to return random data in the response?
Answer: You can configure WireMock to return random data in the response by using response templating and randomization functions.

How do you use WireMock to test APIs with rate limiting and throttling?
Answer: You can use WireMock to test APIs with rate limiting and throttling by simulating the expected behavior of the rate limiting and throttling API and verifying that the API under test correctly handles the rate limiting and throttling.

How do you use WireMock to test APIs with versioning?
Answer: You can use WireMock to test APIs with versioning by creating separate mock servers for each API version and verifying that the API under test behaves correctly based on the API version.