Integration Testing | Manual Testing Tutorial PDF

Integration Testing:

After completion of dependent programs development & Unit testing, the programmers interconnect them. Then the programmers verify the interconnection of the programs in any one of the below four ways.
1. Top-Down Approach
2. Bottom-Up Approach
3. Hybrid Approach
4. System Approach

1.Top-Down Approach:

The interconnection of the main program & some sub-programs is called the Top-Down Approach. Programmers use temporary programs called stubs instead of sub-programs, which are under construction. The other name for stubs is “Called Programs”. A stub returns the control to the main program.
Eg:  

* In this Approach first Parent Modules are developed
* After that Child Modules are developed
* Then interconnect Parent & Child Modules.
* In the interconnection process is there any the sub-module is under construction
then the developers create temporary program Instead of sub modules that is called “Stub”.

2.Bottom – Up Approach:

The interconnection of internal sub-programs without using main programs is called the bottom up approach. In this approach, programmers use a temporary program instead of main program, which is under construction. The temporary program is called “Driver” or “Calling Program”.
Eg: 

* In this approach first Child Modules are developed.
* After that parent modules are developed
* Then interconnect Child Modules with Parent Modules.
* In the interconnection Process is there any main module is under construction
then the developers create temporary program that is called “Driver”.

Difference Between STUB & DRIVER:

3.Hybrid Approach:

Also known as “Sandwich approach”, this is a combination of the Process Top-Down Approach & Bottom-Up Approaches.
Eg:

4.System Approach:

It is also known as “Big Bang Approach”. From this approach, the programmers interconnect programs after completion of all programs development & unit Testing.

Build:
A finally integrated set of all programs is called a “Build” or AUT (Application Under Testing).