Learn JSON Schema Validation with REST Assured

Table of Contents

1. Introduction
2. Creating a JSON Schema
3. Adding JSON Schema to the Class Path
4. Adding Maven Dependency for JSON Schema Validator
5. Creating a Function to Validate JSON Response Against the Schema
6. Using the JSON Schema Validator
7. Verifying the Results
8. Conclusion

Introduction

In this session, we will learn how to validate a JSON response against a JSON schema. We will follow a step-by-step approach to understand the process thoroughly. We will cover topics such as creating a JSON schema, adding the schema to the class path, adding Maven dependency for JSON schema validator, and creating a function to validate the JSON response. By the end of this session, you will be well-equipped to validate your JSON responses effectively.

Creating a JSON Schema

To validate a JSON response, we first need to create a JSON schema. The JSON schema defines the structure, properties, and data types of the JSON response. In most cases, you will receive a JSON schema from the API creators or developers. However, for demonstration purposes, we will create a JSON schema from the JSON response we have received. To convert our JSON response to a JSON schema, we can use a tool like the JSON Schema Converter. This tool will generate a schema based on the provided JSON.

Adding JSON Schema to the Class Path

Once we have created the JSON schema, we need to add it to our project's class path. This step is essential as it allows our code to access the JSON schema. To add the JSON schema to the class path, navigate to your project's target folder and locate the classes folder. Within the classes folder, create a new file named "schema.json" and paste the generated JSON schema into the file. Save the file, and now our JSON schema is added to the class path.

Adding Maven Dependency for JSON Schema Validator

To validate our JSON response against the JSON schema, we need to add a Maven dependency for the JSON schema validator. The JSON schema validator is a library provided by Rest Assured, and it allows us to perform schema validation effectively. To add the dependency, search for "JSON Schema Validator" in the Maven Central repository. Copy the latest version's dependency and paste it into your project's pom.xml file. Save the file, and Maven will automatically download the required dependencies.

Creating a Function to Validate JSON Response Against the Schema

Now, we can move on to creating a function that will validate our JSON response against the schema. This function will allow us to assert that the response matches the expected schema. We can create a new class in our tests package and name it "JsonSchemaValidator." In this class, we can define our validation function by copying and modifying a function from a previous class that makes a GET request. Once we have our function, we need to import the necessary classes and dependencies to use the JSON schema validator effectively.

Using the JSON Schema Validator

With our validation function in place, we can now use the JSON schema validator to validate our JSON response. To do this, we need to call the "matchesJsonSchemaInClasspath" function and provide our JSON schema file as a parameter. This function compares the JSON response against the schema and determines whether they match. If there are any inconsistencies or mismatches, the validation will fail, and we will receive an error message indicating the reason for failure.

Verifying the Results

To verify the validation results, we can run our test. If the JSON response conforms to the schema, our test should pass without any errors. However, if there are any issues, such as incorrect data types or missing properties, the test will fail, and we will receive an error message indicating the cause of failure. By verifying the results, we can ensure that our JSON responses are consistent with the expected schema and adhere to the defined structure and data types.

Conclusion

In this session, we have learned the process of validating a JSON response against a JSON schema. We started by creating a JSON schema and adding it to the class path. Then, we added the required Maven dependency for the JSON schema validator. Afterward, we created a function to validate the JSON response and used the JSON schema validator to perform the validation. Finally, we verified the results to ensure the correctness of our JSON responses. With these steps, we can effectively validate the integrity and conformity of our JSON responses against the expected schema.

Highlights

• Learn how to validate JSON responses against a JSON schema
• Create a JSON schema and add it to the class path
• Add the required Maven dependency for the JSON schema validator
• Create a function to validate the JSON response against the schema
• Use the JSON schema validator to perform the validation
• Verify the results to ensure the correctness of the JSON responses

FAQ

Q: Why is it important to validate JSON responses against a JSON schema? A: Validating JSON responses against a JSON schema ensures that the data received conforms to the expected structure, properties, and data types. It helps to detect any inconsistencies or errors in the response and ensures data integrity.

Q: Can I use a JSON schema received from the API creators or developers? A: Yes, in most cases, you will receive a JSON schema from the API creators or developers. Using the provided schema ensures that you validate the response accurately according to the defined specifications.

Q: How can I run the validation test for my JSON response? A: You can run the validation test by executing the appropriate code that performs the validation. This code should call the JSON schema validator function and provide the JSON schema file as a parameter.

Q: What happens if there is a mismatch between the JSON response and the schema? A: If there is a mismatch between the JSON response and the schema, the validation will fail, and you will receive an error message indicating the reason for failure. This helps in identifying and resolving any issues with the response data.

Q: What are the benefits of validating JSON responses against a JSON schema? A: Validating JSON responses against a JSON schema ensures data consistency, improves data quality, and helps in identifying and resolving any issues with the response. It also enhances the overall reliability and accuracy of the API.

Q: Can I modify the JSON schema to accommodate specific validation requirements? A: Yes, you can modify the JSON schema to accommodate specific validation requirements. You can update the schema to define additional properties, data types, or constraints based on your needs.