Software coding and testing

E-Content
on
Software Engineering
UNIT III: Software Coding and Different Types of Testing
Lesson One: Software Coding Standard
Lesson Two: Software Testing Strategy and Principles
Lesson Three: Software Testing Approaches and Types
Lesson Four: Alpha &Beta Testing and Black Box & White Box Testing
Developed by
Dr. Sandeep Kumar Nayak

Lesson One : Software Coding Standard

Introduction
When you convert a design document into source code, one of your
primary goals should be to write the source code and internal
documentation in such a way so that it is easy to verify that the
source code conforms to the design, and so that it is easy to debug,
test, and maintain the source code. The coding standard below is
designed to assist you in achieving this goal.
Coding standards define a programming style. It is simply a
set of rules and guidelines for the formatting of source code. Coding
standards, also known as programming styles or coding conventions.

Coding Standards
 Coding standards define a programming style.
 Coding Standards give the program a common look and feel
to understand it easily.
 Coding Standards are guidelines for documentation and code
style for the programmer.
 It is simply a set of rules and guidelines for the formatting of
source code.
 A coding standard does not usually concern itself with wrong
or right in a more abstract sense.

Why have Coding Standards?
 Reduce the cost of software
maintains is the most often cited
reason to follow coding standards.
 80% of the lifetime cost of a piece
of software goes to maintenance.
 Coding Standards increases
readability substantially
 Any member of a development should be able to read the code
of another member.

Why Coding Standards Are Important?
Coding Standards are important for safety, security, and reliability.
Every development team should use a coding standard. Even the
most experienced developer could introduce a coding defect
without realizing it. And that one defect could lead to a minor
glitch. Or worse, a serious security breach.
There are four main drivers for using a coding standard:
 Compliance with industry standards (e.g., ISO).
 Consistent code quality — no matter who writes the code.
 Software security from the start.
 Reduced development costs and accelerated time to market.

Benefits of Coding Standards
 Code Integration
 Team Member Integration
 Uniform Problem Solving
 Minimizes Communication
 Minimizes Performance Pitfalls
 Saves Money Due to Less Man Hours
In professional environments, the benefits of coding standards
are readability, maintainability & compatibility. In addition,
today’s enterprise solutions are so complex for that some other
benefits are -

Coding Rules and Guidelines
Coding rules and guidelines ensure that software is:
 Safe: It can be used without causing harm.
 Secure: It can’t be hacked.
 Reliable: It functions as it should, every time.
 Testable: It can be tested at the code level.
 Maintainable: It can be maintained, even as your codebase grows.
 Portable: It works the same in every environment.

Common Aspects of Coding Standards
Here are the some common aspect of coding standards-
 Naming Conventions
 File Naming and Organization
 Formatting and Indentation
 Comments and Documentation
 Classes, Functions and Interfaces
 Pointer and Reference Usage
 Testing of code

Types of Coding
Standards
 Use of comments
 Variable names
 Function names
 Maximum length of a routine (lines of code)
 Maximum number of routines within a class
 Degree of complexity allowed (nested loops, compound
Boolean testing, etc.)
 Naming convention of source code files

 Source code directory structure for developer machines,
build machines and source code control tools
 Source code file contents (i.e. one C++ class per file)
 Ways to indicate incomplete code in source.
Types of Coding
Standards

Conclusion
 The purpose of coding standard is that any developer familiar
with the guidelines can work on any code that followed them.
 We need to write code that minimizes the time it would take
someone else to understand it – even if that someone else is you.
 Sometimes a coding standard is an accepted practice for a
particular language. For instance, programmers generally accept
that when writing C# source code they will write parameters and
private and protected fields using Camel casing. They will write
all other identifiers using Pascal casing.

Lesson Two : Software Testing Strategy and Principles

 It is very important to achieve optimum test results while
conducting software testing without differing from the goal.
Introduction
 Software Testing refers to the process of evaluating attributes
like correctness, completeness, security, consistency,
unambiguousness, quality etc.
 If you were to test the entire possible combinations project
execution time and costs would rise exponentially. We need
certain strategies and principles to optimize the testing effort.

 Software test strategy is a blue print, that describes
the testing approach of the software development cycle. It
is formed to inform project managers, testers, and
developers about some major issues of the testing process.
Software Testing Strategy
 The strategy is a plan for defining the testing approach, what
you want to accomplish and how you are going to do it.
 A number of software testing strategies are developed in the
testing process. All these strategies provide the tester a
template, which is used for testing.

 For every stage of development design, a corresponding test
strategy should be created to test the new feature sets.
 Testing strategy is not a part of testing. It’s the reflection of
whole quality assurance in SDLC.
 The design and architecture of the software are also useful in
choosing testing strategy.
 Testing strategies are describe how the software risks of the
stakeholders are moderated at the test-level, which types of testing
are to be performed, and which entry and exit criteria apply.

1.Analytic testing strategy: This uses formal and informal
techniques to access and prioritize risks that arise during software
testing. It takes a complete overview of requirements, design, and
implementation of objects to determine the motive of testing. In
addition, it gathers complete information about the software, targets
to be achieved, and the data required for testing the software.
2.Model-based testing strategy: This strategy tests the functionality
of the software according to the real world scenario (like software
functioning in an organization). It recognizes the domain of data and
selects suitable test cases according to the probability of errors in that
domain.

3.Methodical testing strategy: It tests the functions and status of
software according to the checklist, which is based on user
requirements. This strategy is also used to test the functionality,
reliability, usability, and performance of the software.
4.Process-oriented testing strategy: It tests the software according
to already existing standards such as the IEEE standards. In addition,
it checks the functionality of the software by using automated testing
tools.

5.Dynamic testing strategy: This tests the software after having
a collective decision of the testing team. Along with testing, this
strategy provides information about the software such as test
cases used for testing the errors present in it.
6.Philosophical testing strategy: It tests the software assuming
that any component of the software can stop functioning
anytime. It takes help from software developers, users and
systems analysts to test the software.

Test Principles will help you create an effective test strategy and
draft error catching test cases. For that, you need to know some
basic testing principles.
Software Testing Principle
1.Testing shows presence of
defects
2.Exhaustive testing is impossible
3.Early testing
4.Defect clustering
5.Pesticide paradox
6.Testing is context dependent
7.Absence of error – fallacy
Here are the common seven testing principles that are widely
practiced in the software industry.

1. Testing Shows Presence of Defects:
The goal of testing is to make the software fail. Sufficient testing
reduces the presence of defects. In case testers are unable to find
defects after repeated regression testing doesn’t mean that the
software is bug-free.
2. Exhaustive Testing is Impossible:
Testing all the functionalities using all valid and invalid
inputs and preconditions is known as Exhaustive testing.
3. Early Testing:
Defects detected in early phases of SDLC are less expensive to fix.
So conducting early testing reduces the cost of fixing defects.

4. Defect Clustering:
Defect Clustering in software testing means that a small module or
functionality contains most of the bugs or it has the most
operational failures.
5. Pesticide Paradox:
Pesticide Paradox in software testing is the process of repeating the
same test cases again and again, eventually, the same test cases will
no longer find new bugs. So to overcome this Pesticide Paradox, it
is necessary to review the test cases regularly and add or update
them to find more defects.

6. Testing is Context Dependent:
Testing approach depends on the context of the software we
develop. We do test the software differently in different
contexts. For example, online banking application requires a
different approach of testing compared to an e-commerce site.

7. Absence of Error – Fallacy:
It is possible that software which is 99% bug-free is still unusable.
This can be the case if the system is tested thoroughly for the
wrong requirement. Software testing is not mere finding defects,
but also to check that software addresses the business needs. The
absence of Error is a Fallacy i.e.
To solve this problem, the next principle of testing states
that Early Testing.

Lesson Three : Software Testing Approaches and
Types

Software Testing is a process, used to identify the correctness,
completeness and quality of developed computer software.
It is the process of executing a program/application under a positive
or negative condition by manual or automated means.
It Checks for the-
 Specification
 Functionality
 Performance
Introduction

Software Testing Approach
A test approach is the test strategy implementation of a project,
defines how testing would be carried out. Test approach has
two techniques:
Proactive - An approach in which the test design process is
initiated as early as possible in order to find and fix the
defects before the build is created.
Reactive - An approach in which the testing is not started
until after design and coding are completed.

Different Test Approaches
There are many strategies that a project can adopt depending on
the context and some of them are:
 Dynamic and heuristic approaches
 Consultative approaches
 Model-based approach that uses statistical information about failure
rates.
 Approaches based on risk-based testing where the entire development
takes place based on the risk
 Methodical approach, which is based on failures.
 Standard-compliant approach specified by industry-specific standards.

Software Testing Types
 Software Testing Methodology is defined as strategies and testing
types used to certify that, the application under testing meets the
client expectations.
 Each testing methodology has a defined test objective, test
strategy and deliverables.
 Software Testing has static and dynamic testing to validate the
software product.

Static Testing, a software testing technique in which the software
is tested without executing the code. It has two parts analysis and
review.
Static
Testing
 Analysis - The code written by developers are analyzed
(usually by tools) for structural defects that may lead to bugs.
 Review - Typically used to find and eliminate errors or
ambiguities in documents such as requirements, design, etc.

Dynamic Testing, is a kind of software testing in witch the software
should be compiled & executed.
Dynamic Testing
Dynamic Testing is further classified in two main categories, on the
basis of software functionality.
Functional Testing
Non-Functional Testing
Parameters such as Memory Usage, CPU Usage, Response Time
and Overall Performance of the software are analyzed.

Functional Testing, is a type of software testing where the system
is tested against the functional requirements and specifications.
Functional Testing
Functional Testing is divided in two type of testing-
White Box Testing
Black Box Testing
It ensures that the requirements are properly satisfied the software
application or not.
Functional Testing are tested by feeding the input and examining
the output.

Testing directly related to the faults remains' in earlier stage or
introduced at coding level. So, each level of testing aim to test
the different aspect of the system.
 Unit Testing
 Integration Testing
 System Testing &
 Acceptance Testing
There are four different level of testing used in testing process.
Levels of Functional Testing

Non-Functional Testing, is a type of software testing which
checks the non-functional aspects such as performance, usability,
reliability, etc. of a software application.
Non-Functional Testing
It is designed to test the readiness of a system as per nonfunctional
parameters which are never addressed by functional testing.

 Non-functional testing should increase usability, efficiency,
maintainability, and portability of the product.
 Helps to reduce production risk and cost associated with non-
functional aspects of the product.
 Optimize the way product is installed, setup, executes, managed
and monitored.
 Collect and produce measurements, and metrics for internal
research and development.
 Improve and enhance knowledge of the product behavior and
technologies in use.
Objectives Non-Functional Testing

Types of Non-Functional Testing
 Performance Testing
 Load Testing
 Failover Testing
 Security Testing
 Compatibility Testing
 Usability Testing
 Stress Testing
 Maintainability Testing
 Scalability Testing
 Volume Testing
 Security Testing
 Disaster Recovery Testing
 Compliance Testing
 Portability Testing
 Efficiency Testing
 Reliability Testing
 Baseline Testing
 Endurance Testing
 Documentation Testing
 Recovery Testing
 Internationalization Testing
 Localization Testing

 In order to be cost effective, testing must be concentrated on
areas where it will be most effective.
Conclusion
 Testing usually related to the faults remaining from earlier
stage, that can lead to a heavy distraction.
 Testing is just a process in order to make your software
application defect free.

Lesson Four : Alpha &Beta Testing and Black Box & White Box Testing

Alpha Testing
 Alpha Testing is a type of acceptance testing, performed to
identify all possible issues/bugs before releasing the product
to everyday users or the public.
 Alpha Testing is carried out in a “Lab Environment” by
the “Testers or Internal Employees” of the organization.
 The focus of this testing is to simulate real users by using a
black box and white box techniques. The aim is to carry out
the tasks that a typical user might perform.

 Beta Testing of a product is performed by “Real Users” of
the software application in a “Real Environment” and can be
considered as a form of external User Acceptance Testing.
Beta Testing
 This is a testing stage followed by the internal full alpha test
cycle. This is the final testing phase where the companies
release the software to few external user groups outside the
company test teams or employees.
 This initial software version is known as the beta version.
Most companies gather user feedback in this release.

Following are the differences between Alpha and Beta Testing:

Alpha Testing Vs Beta Testing
Alpha Testing Beta Testing
It is performed by Testers who are
usually internal employees of the
organization
It is performed by Clients or End
Users who are not employees of
the organization
Alpha Testing performed at
developer's site
It is performed at a client
location or end user
Reliability and Security Testing are
not performed in-depth Alpha
Testing
Reliability, Security, Robustness
are checked during Beta Testing
Alpha testing involves both the
white box and black box techniques
Beta Testing typically
uses Black Box Testing

Alpha Testing Beta Testing
Alpha testing requires a lab
environment or testing
environment
Beta testing doesn't require any lab
environment or testing
environment. The software is made
available to the public and is said
to be real time environment
Long execution cycle may be
required for Alpha testing
Only a few weeks of execution are
required for Beta testing
Critical issues or fixes can be
addressed by developers
immediately in Alpha testing
Most of the issues or feedback is
collected from Beta testing will be
implemented in future versions of
the product
Alpha testing is to ensure the
quality of the product before
moving to Beta testing
Beta testing also concentrates on
the quality of the product, but
gathers users input on the product
and ensures that the product is
ready for real time users.

White Box Testing
 It is also called Glass Box/Clear Box/Structural testing.
 White Box testing based on internal prospective of the
system, and programming skills are used to design test case
for testing.
 Testing is based on internal code structure of the
application.
 Testing usually done at Unit Level Testing.

Unit Level Testing
Unit Testing, is a level
of software testing where
individual units/components
of a software are tested.
 Code Coverage
 Statement Coverage
 Branch Coverage
 Path Coverage
Unit Level Testing Techniques

Black Box Testing
 It is also called Behavior/
Specification/ Input-Output
testing.
 It is software testing method in
which testing evaluates the
functionality of the software
under the test without looking
at the internal code structure.

 Equivalence Partitioning
 Boundary Value Analysis
 Decision Table
 State Transition
Black Box Testing Techniques
 No knowledge of internal design or code is required.
 Test are based on requirement and functionality.
 Black Box Testing can be applied at every level (Unit,
Integration, System & Acceptance) of software testing.

Differences Between Black Box
Testing and White Box Testing
Black Box Testing White Box Testing
Black Box Testing is a software
testing method in which the
internal structure/ design/
implementation of the item being
tested is NOT known to the tester
White Box Testing is a software
testing method in which the
internal structure/ design/
implementation of the item being
tested is known to the tester.

Black Box Testing White Box Testing
Mainly applicable to higher levels
of testing : Acceptance Testing
System Testing
Mainly applicable to lower levels
of testing : Unit Testing
Integration Testing
Generally, independent Software
Testers
Generally, Software Developers
Not Required Required
Not Required Required
Requirement Specifications Detail Design

Software coding and testing

Recommended

More Related Content

What's hot (20)

Similar to Software coding and testing (20)

Recently uploaded (20)

Software coding and testing