Explaining about Unit Testing & Integration Testing..?

Here,we discussing about unit testing and supporting techniques..

Unit Testing:

      - A smallest testable portion in the source-code of the application is called Unit testing.

      - Individually every program working or not OR conducting testing on each & every program individually,it's called Unit Testing.

      - while conducting unit testing, Programmers follow below white-box testing techniques,

         i,e...

                 1. Basic path coverage

                 2. Control structure coverage

                 3. Program technical coverage

                 4. Mutation coverage

- To conduct above Testing,programmer follow syclo-metric of complex pattern.

Integration Testing:

      - After completion of Unit testing,combine all units check interactions among all those units which is called " Integration Testing ".

      - Based on the availability of the source code,the integration testing will be carried out in four approaches..

1.Top-down Approach

2.Bottom-up Approach

3.Hybrid Approach

4.Big-bang Approach

1.Top-down Approach:

      - this approach is recommended,if there are any incomplete programs at bottom level in this approach,integration testing will be carried out from top to bottom.

      - the incomplete program at bottom level will be replace with STUBS.(STUB is a temporary program)

2.Bottom-up Approach:

      - this approach is recommended when there are incomplete programs at top level.

      - in this approach,integration testing will be carried out from bottom to top.

      - incomplete program at top level will be replaced with Drivers.

3.Hybrid Approach:

     - the combination of top-down and bottom-up approaches of the Integration testing is called " Hybrid approach".

     - in this,middle-level modules are testing using the Drivers and Stub's and hybrid approach is called as "Sand witch approach".

4.Big-bang Approach:

    - this approach is recommended,once 100% program completed and every unit tested.

    - conducting integration testing between all modules is called "Big-bang approach".

NOTE:

 - Unit testing and Integration testing are done in the source-code of application by programmer,not test engineer.
 - White-Box Testing = Unit Testing + Integration Testing.