Best Practice — Advanced

Variablize for Test Reuse

Domain, endpoints, and data sets are some of the parts of a test that should be easy to change quickly. You should never have to duplicate a test to execute it against a new staging environment. If you are doing that than your system needs to be reconsidered.

As much as possible aim to have only a single test of a certain type. If you built a partner API, then try to have a single detailed test that can be a regression test during a CI pipeline, and then also used to monitor the live environment. [Learn More]

Business Logic Validating

As described in Course 1, it is important to go beyond the technical facts of a payload. You should also have knowledge as to the business objects. This means that if the Uber payload includes a reference to UberSidecar, but Uber hasn’t announced a Sidecar product yet, this is a major issue for them from a technical and business secrets perspective.

Perhaps they have a major advertising initiative to announce the ability to order a ride in the sidecar of a motorcycle, and this would undermine that. It’s important that your tests are knowledgeable about the goal of the APIs technically, as well as from a business perspective.

Using Lots of Data

One of the most common errors we see with testing is using the same small set of data for every test. A CSV with 50 product IDs is a good start, but now that we can automate this work there is no reason to not write a much more comprehensive test that can validate hundreds of product IDs. You must break free from using small CSV files for datasets.

If you are already using databases or APIs that’s great! If not, we suggest you start this process as well. A test is only as good as the amount of information it is testing against.
[Learn More Using Files | Using JDBC]

Integration / End-to-End Test

Most API programs are a collection of APIs that are meant to interact with each other. Therefore, it is important to create tests that do exactly that. A singular test that goes through a series of calls and validates the responses at each stage. This is what is called an integration test, although it is also called an end-to-end test.

This means writing detailed tests that reproduce normal user flows. For example, if we are talking about an ecommerce platform, a normal user flow would be:

Search > View Product Details Page > Add to Cart > Checkout

A functional test for just the Search API is a great start, but the entire flow also needs to be validated. You should have as many integration tests as there are expected user flows. [Learn More]

Confirm Response Matches Request

This is in the same thinking as the above, but with that advent of PSD2 and Open Banking it’s worth mentioning on its own. When you are requesting information, such as your personal banking history, it is important to make sure only your information is returned. It is also important to validate you can do wildcard searches and get the results of other.

That is exactly the sort of functional error that causes a huge vulnerability for large organizations like the United States Post Office.

Integrations Galore

Every company has an existing workflow, and it’s important to choose a platform that helps keep those integrations seamless. In the basics we talked about integrating with your CI pipeline, but it’s also useful to have notifications and data in one place. If your organization has a lot invested in Slack, Kibana, and TestRail (for example) than having API test notifications and results in one place is imperative. [Learn More]