Introduction to Interface Testing:

When an application or a website or a software is developed, there are several components like a server, database etc.

The interface is a connection between these components which facilitates and integrates the communication between them.

For a computer system, an interface can be web services, APIs etc. The communication between the server, database etc of an application or a website or a software can affect the overall performance of the system hence this communication media i.e. the interface also needs to be verified and tested.
Interface testing is testing which is done to verify the interface functionality.

The top tools for interface testing:

1) Postman
Postman is a REST-client tool which is simple and it's chrome extension its leverage is that that it starts quickly. Postman’s UI helps in checking the received response and building requests.

Postman is a good option for the automation, for such people, those don’t like to use the IDE for the same coding language. Postman has the version available for Mac, Linux and Windows.

2) JMeter
JMeter is interface testing tool which is also widely used for the load testing. JMeter provides a record and playback functionality support and it is easy to read and understand the HTML reports those are generated by JMeter.

JMeter is allowed us to create unique parameters for the testing as it is compatible with the CSV files.

JMeter is easy to integrate with the Jenkins so that the test can be included in the Continuous Integration CI

Jmeter would be a worthy choice for the load and interface testing.

3) SoapUI
SoapUI would be a great choice if the team do the API testing only. SoapUI is the completely functional testing tool which is devoted to API testing. In this, the data can be passed in CSV format or excel format as its supports data-driven testing. SoapUI Pro is a paid version which compiles with the better and improved features for the API and Web service testings.

Types of the Interface Testing

The principe of the Interface Testing done on the messaging layer of the computer system architecture. It involves testing the SOAP UI web service and API with XML or JSON format.

Following practices are typically involved in the Interface Testing:-

Unit Testing - Verifying the functionality of each individual feature.

Functional Testing - Verifying the functionality of complex scenarios which involves test case creation, regression, validation etc.

Load testing - The performance under load is verified.

Runtime error detection - Monitoring the application for scenarios like runtime race, resource leaking, etc.

Workflow testing - This is done to ensure if the interface engine is handling the workflow as expected.

Strategy or the Approach followed for Interface testing

Interface testing is equally essential/important just like any other testing as it ensures performance, seamless functioning etc. of various data-driven systems and the applications by verifying the communication between the systems, networks and database.

To verify the dependencies of the application with another app, then the Interface testing plays a major role in it.

There are few steps which ensure successful interface testing:

1) Define your Requirement: Understanding of the application is essential for creating the Interface tests

2) Expected Output: Output that expecting from our tests should be finalized.

3) Start Small: Start creating small test cases and verify if the output is as expected or not.

4) Define the Start and Stop points: Identify the entry and exit criteria to measure when we are good to start test execution and when to stop testing