How to handle validation errors in Web API?

How to handle validation errors in Web API?

Things to consider when implementing Web API

1. Validate everything. Each and every request should validate before processing it whether an Action method is GET, POST, PUT or DELETE.
2. Don’t assume about the data you’re receiving.
3. Validation as a future-proof quality check.
4. Clean code is Important.

How to handle exception in API?

What Are Good API Errors?

1. Good API errors differentiate client and server errors.
2. Good API errors use status codes appropriately.
3. Tip 1: Stick with well-known codes.
4. Tip 2: Avoid codes you don’t understand.
5. Tip 3: Provide the right number of errors.
6. Tip 4: Roll up to the most relevant error.
7. Tip 5: Explain what went wrong.

How do you validate API responses?

The first step in testing is to make sure that you can successfully connect to the REST API using the configured type of authentication. From the API documentation, find a request URL to test that provides a response. Using a GET to test the authentication is often the simplest way to make sure you can connect.

Is it enough to validate an API request?

However, validation of our requests is not enough, unfortunately. In addition to validation, it is our responsibility to return the relevant messages and statuses to our API clients. I wanted to deal with these two things in this post.

How are errors handled in.net core validation?

The Validation rules based on FluentValidation framework which allows you you build rules in fluent format. The last turn I will cover errors/exception handling. I address this topic to the end as all validation components generate exceptions and the centralized component that handles them and provide proper JSON error object is required to have.

What happens when there are multiple validation errors?

That is, in multiple validation errors scenario, first we complain about the first validation error, then the second error and so on. If we could report all validation errors at once, in addition to have a more pleasant API, we could save some extra round trips.

How to validate parameters of API action methods?

To validate parameters of API action methods I will create an attribute and move validation logic. Logic inside attribute checks if parameters contains validation attributes and validates the value. Now attribute can be added to the action method, if necessary. (examples below) Now the attribute can be added to API method, like on example below.