Software Testing Fundamentals

Intro to Software Testing

• Includes agenda items like what is software, what is software testing, why is testing important, what is a bug, types of errors, testing specifications, and types of software testing.
• Discusses SDLC and STLC, and V models.

What is Software

• Software is computer programs plus associated documentation.
• Documentation types include user, technical, and marketing.

What is Software Testing

• Software testing checks whether the software product aligns with expected requirements and is defect-free.

Why Testing is Important

• Important for finding and correcting defects.
• Checks if user's needs are satisfied.
• Crucial for avoiding user-detected problems, and providing quality products.

Objectives of Testing

• Ensure requirements match customer needs.
• Define and prevent defects, provide quality assurance, and generate high-quality test cases

Why Software has Bugs

• Bugs happen due to miscommunication, time pressure, programming mistakes, and changing requirements.

Common Misunderstandings in Software Testing:

• Testing is not the same as debugging.
• Testing is always necessary.
• Testing activities should not start only after the coding is complete.
• Testing never ends.
• Testing is a creative task.

What is a Bug

• A bug is a deviation of the actual result from the expected result.

Types of Errors

• Error: Is a human action that produces an incorrect result that results in a fault.
• Bug: Is the presence of error at the time of execution of the software.
• Fault: State of software caused by an error.
• Failure: Deviation of the software from its expected result, and is considered to be an event.

Testing specification

• Test specification involves creating test cases based on code and specifications.
• It ensures program meets requirements by testing various inputs such as a valid word, a null entry, or an unexpected word.

Test Cases

• Valid inputs such as "cat" or "frog" are valid inputs, therefore "cat is a great animal" and "frog is a great animal" are both expected results.
• A null input results in "You didn't type anything"
• Invalid inputs such as "dragon" triggers output "You didn't enter the expected word".

Bug Life Cycle

• A bug progresses through stages: New/Open, Assigned, Fixed, Re-test, and Close
• Bugs can be Re-opened if not properly fixed, also, bug statuses may include Duplicate, Invalid, Deferred, and Not Reproducible.

Software Free Errors

• Tester must ensure that 100% of the software work effectively and is error-free.
• Bugs will be missed by testers, that testing cannot cover 100% of possibilities.

Types of Software Testing

• Include Functional, Non-Functional, and Maintenance Testing

Types of Software Testing in Software Engineering

• Functional Testing types: Unit, Integration, and UAT(User Accepted Testing)
• Non-Functional Testing types: Performance, Usability, Scalability
• Maintenance types: Regression, Maintenance

Level of Testing

• Testing is conducted at different levels: Unit Testing, Integration Testing, System Testing, and Acceptance Testing

Unit testing example

• Testing individual modules or components in isolation.

Integration testing example

• Focuses on how different units interact with each other.

System Testing

• Tests the entire system, ensuring different components work together.
• System testing includes functionality, performance, scalability, reliability, configuration, and security.

Testing Methodologies

• Black box testing: Doesn't require internal program design knowledge and tests are based on the requirements and functionality.
• White box testing: Requires internal program design and code knowledge, and tests are based on code statements, branches, paths, conditions.

Black Box Testing

• Applied for functional and non-functional testing, without reference to the internal structure of the system.
• Focuses on requirements, input, output and events.

Black box testing techniques.

• Equivalence partitioning: If a Value range is between 1 and 100 then print "Pass", invalid partitions would include -1,0 and 101,.
• Boundary value analysis: If a Value is between 1 and 100 exclusive, then print "Pass", lower boundary is 1 and upper boundary is 100.
• Decision table testing: Tests system behavior for input combinations.
• State transition testing: Outputs are triggered by input condition changes.

White box testing techniques.

• In Software Engineering, the goal is to verify code decision branches, loops, and statements.
• Statement Coverage: Needs one test case to check all the lines of code
• Branch Coverage: Evaluates the false conditions, ensuring maximum coverage.
• Path Coverage: Used to test complex code snippets and involves loop statement combinations.

Test Cases Objectives

• Test to pass: assures software minimally works and applies straightforward test cases
• Test to fail: chooses test cases to reveal software weaknesses and to break the software

Software Deployment Cycle

• The activities go from developers to software testers and deployment.

SDLC and STLC

• SDLC: Software Development Life Cycle is the sequence of activities by the Developers to design high-quality software.
• STLC: Software Testing Life Cycle consists of the activities by the Testers for testing the software product.

SDLC

• SDLC includes planning, analysis, design, implementation, testing and integration, and maintenance

STLC

• Consists of requirement analysis, test planning, test case development, test environment setup, test execution, and test closure.

V-Model

• Highlights relationship between development and testing phases
• Requirement Analysis relates to System Testing
• High Level Design relates to Integration Testing
• Low Level Design relates to Unit Testing
• Coding relates to Unit Testing