Integration Testing

Overview

Integration testing is a level of software testing where individual units are combined and tested as a group. The purpose of this level of testing is to expose faults in the interaction between integrated units. Test drivers and test stubs are used to assist in Integration Testing.

Definition

Integration testing is defined as a type of testing where software modules are integrated logically and tested as a group. A typical software project consists of multiple software modules, coded by different programmers. The purpose of this level of testing is to expose defects in the interaction between these software modules when they are integrated.

Types of Integration Testing

There are different types of integration testing, including:

Big Bang

In the Big Bang approach, all or most of the units are combined together and tested at one go. This approach is applicable when the testing team receives the entire software in a bundle.

Top Down

In the Top Down approach, top level units are tested first and lower level units are tested step by step after that. This approach is taken when top level units are developed first.

Bottom Up

In the Bottom Up approach, bottom level units are tested first and upper level units step by step after that. This approach is taken when bottom level units are developed first.

Sandwich/Hybrid

The Sandwich/Hybrid approach is a combination of Top Down and Bottom Up approaches.

Integration Testing Approach

The approach for integration testing can be carried out in the following ways:

Incremental

In the Incremental approach, two or more logically related modules are integrated and tested. After testing these modules, they are then used to test larger groups of modules, and this process continues until all the modules are tested together as a complete system.

Non-Incremental

In the Non-Incremental approach, all the modules are integrated together and tested at once. This approach is also known as the Big Bang approach.

Integration Testing Process

The process of integration testing includes the following steps:

1. Prepare the integration test plan 2. Create the test cases for integration 3. Arrange the modules in the order of testing 4. Conduct the tests 5. Document the results

Advantages of Integration Testing

Integration testing offers several advantages, including:

- Detecting issues related to data communication among modules - Helping to identify and fix the issues not caught during unit testing - Ensuring that the integrated modules work smoothly - Verifying the functional, performance, and reliability requirements of the software

Disadvantages of Integration Testing

Despite its advantages, integration testing has some disadvantages as well, such as:

- It can be more time-consuming and costly compared to other types of testing - It requires a good understanding of the system and its interactions - It can be difficult to isolate the root cause of the errors

Tools for Integration Testing

There are several tools available for integration testing, including:

- JUnit - NUnit - TestNG - Jasmine