First Task

First Task

1. Test Driven Development

   • Cost
     • Good Testing
       • Expensive but worth
         • Useful over time
           • Reduces chance of failure
     • Bad Testing
       • Extremely expensive
         • Not sustainable
           • Increased chance of failure
     • Impact
   • Testing
     • Verification
       • Dynamic
         • Regular Test Motions
           • Go Step By Step
             • Run with different inputs
               • New Trial every time
                 • Execute in runtime
                   • Check Behaviour
               • Make the System Fail
           • Work until done
             • Run with different implement
               • Many Levels
                 • Unit Testing Integration Testing System Testing Acceptance Testing Regression Testing
               • New Items every time
           • Individual work for immediate use
       • Static
         • Incremented Test Motions
           • Syntax Check
             • Fix as errors pop up
           • Method Check
             • Examine code without execution
               • Tools analyze for potential issues
                 • Performed early in dev process
                   • No runtime or compilation
         • Individual work for long term use
       • Review
         • Code is mostly done
           • Discussion used to test
             • Group used to Manual
           • Test for bugs
             • Inspection: Formal Checklist + Moderator
             • Reviews: Less Formal + Peers
             • Walkthroughs: Informal + Author
       • Formalization
         • Use hard proofs
           • Software and Math Heavy
             • Complex and Difficult
               • Used to guarantee
                 • Overkill
                 • Time Consuming and Expensive
           • Good in Practice
     • Validation
       • Inside Organization
         • Developer Testing
           • Alpha Testing
       • Outside Organization
         • Beta Testing
           • Product Release
   • Test is written before the class
     • Write Test Code Write Functional Code Refactor
       • Red
         • Fail
       • Refactor
         • Improve
       • Green
         • Work
     • Discipline Specification Reduce Error Easy Change

2. Code Smells

   • A quick spot that indicates problems in code
     • Found during refactor or examinations
     • Comes from rushed design and disregard for tech debt
       • Right Way: Good Practice
       • Fast Way: Hacked Together
   • Process of improving code into clean and simple design
     • Bloaters
       • Something that has grown too large
         • Smells in Group: Long Method Large Class Long Param Data Clumps
         • Solution: Extract Method Extract Class Replace Param Replace Object
     • Change Preventers
       • Smells that hinder changing or further development
         • Smells in group: Divergent Change Shotgun Surgery
         • Solution: Extract Class Extract Method Move Methods
     • Couplers
       • Measure of how close connected two routines or modules are
         • Smells In Group: Feature envy Inappropriate Intimacy Middle Man
         • Solution: Move Method Bidirectional Associate Inline Class
     • Dispensables
       • Represents something unnecessary that should be removed from source code
         • Solution: Inline Class Move Method Extract Method Encapsulation Extract Method
         • Smells In Group: Lazy Class Data Class Duplicated Code
     • Object Orientation Abusers
       • Cases where solution does not fully exploit OOD
         • Solution: Use Polymorphism Extract Method Push Method Implement Interface
         • Smells in Group: Switch Statements Refused Bequest

3. Refactoring

   • Small techniques to improve program design
     • Goal is to keep program maintainable
       • Behavior Preserving
   • Requirements Change
     • Agile
       • Makes design more Flexible
         • Do not refactor when code is broken
         • Do not refactor when deadline approaches
         • Do not refactor when uneeded
     • Design Improvements
       • Copy Paste for new Method
   • Types of Refactoring
     • Method Rename Collapse Hierarchy Consolidate Conditional Decompose Conditional Extract Class Extract Method
       • Modern IDE's can do this
       • Extract Method
         • Large Code reduced to method + call to method
       • Consolidate Conditional
         • If there are conditionals with same result, combine and extract
       • Decompose Conditional
         • If a conditional is complex, extract method, give name, modify then/else
       • Extract Class
         • If a class is doing work of 2 classes, separate
   • Tools
     • Refactor when approving other developers PR
       • Based on many different rules for different languages covering code smells, test coverage, code security
         • Automated tools are important due to lack of time to make changes manually
       • Use when you have to add a feature
       • Use during code review
       • Use when fixing a bug