Introduction to OO Program Design
Software College of SCU
Instructor: Shu Li
Email: [email protected]
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Unit 2.1 Implementing Classes
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2.1.4 Unit Testing
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2.1.4.1 Overview of Software Testing
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2.1.4.2 Software Testing Methods
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2.1.4.3 Software Test Types
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2.1.4.4 Unit Test
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2.1.4 Unit Testing
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2.1.4.1 Overview of Software Testing
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2.1.4.2 Software Testing Methods
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2.1.4.3 Software Test Types
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2.1.4.4 Unit Test
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2.1.4.1 Overview of Software Testing
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Purpose of Software Testing
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Role of Testers
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Truths and Realities
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Software Testing
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Any activity designed to evaluate an attribute or
capability of a program to determine that it meets required
standards.
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Purpose of Software Testing
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Measure Quality
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Validation: Prove it works (Do the right thing)
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Verification: Do it right
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Provide information
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To development and management
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For risk evaluation
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Watching the process not just the product
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Software Quality
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Doing the right things right at the right time
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Conformance to applicable standards
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Customer focus
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Features vs. Flaws
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Engineering focus
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Maintainability, sustainability, testability, etc.
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Quality is defined as conformance to requirements, not as
“goodness” or “elegance”
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Quality also means “meet customer needs”
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Role of Testers
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Find Bugs
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Break Software
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Keep Developers Honest
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Defect Prevention
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Quality Measurement
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Drive quality upstream
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Customer focus
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Goal: ensure the quality
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Truths and Realities
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The earlier a bug is fixed, the less costly it is.
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Before code review
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By code review
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By testing
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By Beta testers
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After product is released
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Prevention vs. Detection
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“The mere act of designing a test is a powerful bug
preventer”
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Truths and Realities
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Thorough Testing vs. Risk-based testing
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Thorough Testing: testing for everything
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Risk-based Testing
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Identify and analyze risks to enable informed and calculated
decisions
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Look for the best use of test resource
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Risks can be categorized by severity and likelihood.
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2.1.4 Unit Testing
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2.1.4.1 Overview of Software Testing
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2.1.4.2 Software Testing Methods
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2.1.4.3 Software Test Types
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2.1.4.4 Unit Test
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Software Testing Methods
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Black-box Testing
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White-box Testing
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Risk-based Testing
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Black-box Testing
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Doesn’t require explicit knowledge of the internal
structure of the system
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Primarily focuses on functional requirements
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User-perspective
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Validates the spec
Input
Output
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White-box testing
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Requires knowledge of the internal structure
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Primarily focuses on code coverage ( o
)
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e.g. write tests to “cover” internal paths
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Good for testing individual functions
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Developer’s tests
Input
Output
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Risk-based Testing
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Used to determine:
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What to test
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Test priority
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Test coverage
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Risk-based Testing
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Risk-based Testing
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Two basic factors for determining risk:
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Impact to the customer
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Probability of customer experiencing issues
