Introduction-Software-Testing-for Developers.pdf

Introduction Test Driven
Development (TDD)
Agus Kurniawan

Agenda
• Software Lifecyle
• Software Testing
• The Software Testing Life Cycle
• Requirement Analysis
• Test Planning
• Test Preparation
• Test Environment Readiness
• Test Execution
• Test Cycle Closure
• TDD

Software Lifecyle
▪ Software Lifecycle: the period of time that
begins when a software product is
conceived and ends when the software is
no longer available for use.
▪ The software lifecycle typically includes a
concept phase, requirements phase,
design phase, implementation phase,
test phase, installation and checkout
phase, operation and maintenance
phase, and sometimes, retirement
phase.
▪ Note that these phases may overlap or be
performed iteratively

Testing in
Software Lifecyle
▪ Testing must be integrated into the
software lifecycle to succeed.
▪ This is true whether the particular lifecycle
chosen is sequential, incremental,
iterative, or spiral.
▪ Proper alignment between the testing
process and other processes in the
lifecycle is critical for success

Example: Sequential
SDLC
▪ Requirements defined early and formally
▪ Testing can starts early, system test level can
follow an analytical requirements-based test
strategy.
▪ Using a requirements-based strategy in a
sequential model, the test team would start—
early in the project—planning and designing
tests following an analysis of the requirements
specification to identify test conditions.
▪ This planning, analysis, and design work might
identify defects in the requirements, making
testing a preventive activity. Failure detection
would start later in the lifecycle, once system
test execution began.

Example: Incremental
SDLC
▪ The test team won’t receive a complete set of
requirements early in the project, if ever.
Requirement changes evolutionary.
▪ Rather than analyzing extensively documented
requirements at the outset of the project, the
test team can instead identify and prioritize
key quality risk areas associated with the
content of each sprint;
▪ follow an analytical risk-based test strategy

Testing Alignment to SDLC
• No matter what the lifecycle—and indeed, especially with the more fast-
paced agile lifecycles—good change management and configuration
management are critical for testing.
• A lack of proper change management results in an inability of the test team to
keep up with what the system is and what it should do.

The Software Testing Life Cycle
(STLC)
◼ the sequence of activities conducted to perform Software Testing.
◼ Consists of 6 phases

Test Cycle Closure
Test Execution
Test Environment
Readiness
The Testing
Lifecycle
Requirement
Analysis
Test Preparation
Test Planning
The Software Testing Life Cycle (STLC)

Requirement
Analysis
Review
Requirements
Requirements are reviewed
by the Test Team.
Requirement
Traceability Matrix
Requirements captured in
Excel or in a tool to track of
testing coverage
(requirements vs. tests)
Requirement Walk-
through Meeting Held
Test team meets with the BAs
and Dev to address any
questions, gaps, or concerns.
Prioritize
Requirements
(Risk Based Testing)
Test Lead works with BAs &
SMEs to prioritize the
requirements (High, Medium,
Low)
Identify and Capture
Questions about
Requirements
Questions, gaps, or concerns
are identified and captured in
a Query log.

Test
Planning
The Test Plan
is defined
The Test Lead defines the testing
strategy for the project and
captures it in a document called
the Test Plan.
Test Effort
Estimation
The Test Lead determines the
level of effort which will be
required to successfully
complete the testing

Test
Preparation
Once the requirement walk through is completed test preparation can
begin
Tests are
Identified
The Test Team identifies
the Tests needed to
validate each
requirements.
Peer Review
Tests are reviewed by
the QA Lead to ensure
proper coverage
between tests and
requirements.
Test Cases are
Reviewed and
Finalized
Tests cases are
reviewed to ensure they
are ready for execution.
Test Cases
are Created
Info about the test, Step
by step instructions
and expected results
are captured.

Test Environment
Readiness
Test Environment
Setup
The development
team will setup the
test environment
where testing will take
place.
Acceptance Test
Performed by QA
QA Team performs an
acceptance test to
ensure the
application is ready
for formal testing to
begin.
Once the application has been
developed the Test
Environment can be setup

Test Execution
Activities
Once the Test Environment Setup and Test
Preparation is completed, Test Execution can
begin.
Test Execution
Test Cases are executed
and actual results are
captured. A Test either
passes or fails.
Defect
Reporting
If a test case fails
because of a problem,
the problem is
reported as a defect.
Defect
Resolution
Defects are resolved and
then reassigned back to
test team for retesting.
Regression Testing
Testing done to ensure that defects
were not introduced from the fixing
of defects.
User Acceptance
Testing
Testing performed by the business
before accepting the application

Test Cycle
Closure
Once Test Execution is complete
Test Cycle Closure can begin
Execution
Summary
Report
Summary of all tests
executed, identified
defects, and defects
not yet resolved.
Meeting with
Stakeholders
Execution summary
report presented to
the stakeholders for
sign-off.
Lessons
Learned
Meeting
Meeting to discuss
what went right and
what went wrong.

REQUIREMENT ANALYSIS
◼ Review requirements
◼ Identify and capture questions about
the requirements
◼ Meet with the SMEs and Dev to address
questions, determine what is in-scope
and out-of-scope for testing, and
identify requirement priorities.
◼ The RTM is created.
TEST PLANNING
◼ The Test Plan is defined.
◼ Testing Effort is re-visited.
TEST PREPARATION
◼ Identify Tests needed to verify
requirements.
◼ The QA Lead reviews tests identified to
ensure nothing was missed.
◼ Test cases are created.
◼ Test cases are reviewed to ensure they
are ready for execution.
TEST ENVIRONMENT READINESS
◼ The Test Environment is setup by the
developers
◼ QA performs an acceptance test
before formal testing begins.
TEST EXECUTION
◼ Tests are executed
◼ Testing results are captured
◼ Report defects and retest once
resolved
◼ Retest failed and blocked tests
◼ Perform Regression Testing
◼ User Acceptance Testing is done by the
business.
TEST CYCLE CLOSURE
◼ The test execution summary report is
created and presented to the stake
holders for sign off
◼ Lesson learned meeting held
TO STUDY AND MEMORIZE

Categories of Software Testing
• Manual Testing: Testing performed by human testers without the
use of automated tools.
• Automated Testing: Testing performed using automated tools to
execute test cases.
• Static Testing: Testing without executing the code (e.g., code
reviews, walkthroughs).
• Dynamic Testing: Testing by executing the code (e.g., functional
testing, performance testing).

Some test techniques
Static Dynamic
Structural
Behavioural
Functional
Non-functional
Reviews
Walkthroughs
Desk-checking
Data
Flow
Symbolic
Execution
Definition
-Use
Statement
Branch/Decision
Branch Condition
Branch Condition
Combination
LCSAJ
Arcs
Equivalence
Partitioning
Boundary
Value Analysis
Cause-Effect Graphing
Random
Usability
Performance
Static Analysis
Inspection
Control
Flow
etc.
etc.
etc.
etc.
etc.
State Transition

Types of Tests
• Functional
• Performance
• Regression
• Load
• Worst case
• Perfective
• Exploratory
• Random-Input
• Certification
• Stress
• Usability
• Real Time
• Life
• Collision
• Security
• Installation
• Recovery

Test Levels
• Unit
• Component
• Integration
• System
• Field
• Acceptance
many variant
Integration Testing:
• Component integration
• System integration
• System of system
• Conglomeration of System
Acceptance:
• User acceptance test
• Regulatory acceptance test

Introduction-Software-Testing-for Developers.pdf

VV&T
• Verification
• the process of evaluating a system or component to
determine whether the products of the given
development phase satisfy the conditions imposed at the
start of that phase [BS 7925-1]
• Validation
• determination of the correctness of the products of
software development with respect to the user needs
and requirements [BS 7925-1]
• Testing
• the process of exercising software to verify that it
satisfies specified requirements and to detect faults

Verification, Validation and Testing
Verification
Validation
Testing
Any

Test Level’s Tasks
▪ Clearly defined test goals and scope
▪ Traceability to the test basis (if available)
▪ Entry and exit criteria, as appropriate both for the level
and for the system lifecycle
▪ Test deliverables, including results reporting
▪ Test techniques that will be applied, as appropriate for
the level, for the team and for the risks inherent in the
system
▪ Measurements and metrics
▪ Test tools, where applicable and as appropriate for the
level
▪ And, if applicable, compliance with organizational or
other standards

Additional Testing
• ■ Hardware-software integration testing
• ■ Feature interaction testing
• ■ Customer product integration testing

28
Test Strategies
• Top down
• Bottom Up
• Black box
• White box
• Simulation
• I/O first
• Alpha/Beta testing
• Fault insertion
• Fault-Error handling
• Equivalence class
partitioning
• Boundary value
analysis
• Cause effect graphing
• Error guessing
• Customer defects

Specific Systems
• System of system
• independent systems tied together to serve a common purpose
• Safety critical system
• A system whose failure or malfunction may result in death or serious
injury to people, or loss or severe damage to equipment, or
environmental harm.

System of System
▪ Systems of systems are independent systems tied together to serve a
common purpose.
▪ Since they are independent and tied together, they often lack a single,
coherent user or operator interface, a unified data model, compatible
external interfaces, and so forth.

System of System:
Characteristics and risks:
• ■ The integration of commercial off-the-shelf (COTS) software along with
amount of custom development, often taking place over a long period.
• ■ Significant technical, lifecycle, and organizational complexity and
heterogeneity. This organizational and lifecycle complexity can include issues
of confidentiality, company secrets, and regulations.
• ■ Different development lifecycles and other processes among disparate
teams, especially—as is frequently the case—when insourcing, outsourcing,
and offshoring are involved.

System of System:
Characteristics and risks:
▪ Serious potential reliability issues due to intersystem coupling, where one
inherently weaker system creates ripple-effect failures across the entire
system of systems.
▪ System integration testing, including interoperability testing, is essential.
Well-defined interfaces for testing are needed.

Lifecycle Implications
▪ Multiple level integration testing.
▪ Multiple version on each system. Unless all systems to be built by
one (large) organization and with same development approach.
▪ Long duration of development. (small = 1 year, 40-50 people)
▪ Large size & complexity → project breakdown →
▪ formal information/knowledge transfer
▪ transfers responsibility
▪ handoffs
▪ The systems evolving.

Test process in a system of system

Safety Critical System
• A system whose failure or malfunction may result in death or serious injury to
people, or loss or severe damage to equipment, or environmental harm

What to measure?
• ■ Planned schedule and coverage
• ■ Requirements and their schedule, resource, and task implications for
testing
• ■ Workload and resource usage
• ■ Milestones and scope of testing
• ■ Planned and actual costs
• ■ Risks; both quality and project risks
• ■ Defects, including total found, total fixed, current backlog, average
closure periods, and configuration, subsystem, priority, or severity
distribution
• …. and so on…. no end

Metric and measurement
1. Definition
2. Tracking
3. Reporting

Definition
▪ Define useful, pertinent and concise set of
quality and test metrics
▪ Too large metrics →
▪ Difficult and expensive to measure
▪ Confusing rather than enlighting
▪ Uniform and agreed upon interpretation of
metrics →
▪ Minimize disputes and opinions about meaning of
certaion measures of outcomes, analyses and trends

Tracking
▪ use automated tool
▪ reduce the time required to capture, track, analyze, report, and measure
the metrics.
▪ be sure to apply objective and subjective analyses for specific
metrics over time.
▪ be aware of and manage the tendency for people’s interests to
affect the interpretation they place on a particular metric or
measure.
▪ Usually people’s interests affect their conclusions

Reporting
• Most importantly, reporting of metrics and measures should
enlighten management and other stakeholders, not confuse or
misdirect them.
• Should be easily understood, not overly complex and certainly not
ambiguous

What is TDD?
• Definition: Test-Driven Development (TDD) is a software
development process in which tests are written before code.
• Principle: "Red, Green, Refactor"
• Red: Write a failing test
• Green: Write code to pass the test
• Refactor: Improve the code

Benefits of TDD
• Improved Code Quality: Ensures that code works as expected
• Reduced Bugs: Catches bugs early in the development process
• Documentation: Tests serve as documentation for code behavior
• Refactoring with Confidence: Safe to refactor code without
breaking functionality
• Better Design: Encourages simpler, more modular code

TDD Workflow
1. Write a Test: Write a test for a new function or feature.
2. Run the Test: Ensure the test fails (Red).
3. Write Code: Write the minimum amount of code to pass the
test.
4. Run the Test Again: Ensure the test passes (Green).
5. Refactor: Improve the code while keeping the test green.
6. Repeat: Continue with the next test.

Best Practices
• Write Simple Tests: Keep tests simple and focused on one
functionality.
• Test Coverage: Aim for high test coverage, but prioritize critical
code paths.
• Continuous Integration: Use CI/CD pipelines to run tests
automatically.
• Collaboration: Encourage team collaboration and code reviews.
• Documentation: Maintain good documentation for tests and
code.

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