Code & Coffee - 1/28/2022

 

Notes for Code & Coffee: 1/28/2022

• Replacing the six year old mouse
• Tried and didn't like two new mice
• Talked about battery life of wireless mice
• Trackball vs. Mouse vs. Trackpad vs. Trackpoint
• Trackpoint is the best but overuse causes pain, so just use vim
• Vimium for Chrome
• https://chrome.google.com/webstore/detail/vimium/dbepggeogbaibhgnhhndojpepiihcmeb?hl=en
• SICP for javascript is available for pre-order
• link
• Found this out from hacker newsletter
• https://hackernewsletter.com/
• Also check out:
• https://quastor.org/
• and http://www.pointer.io/
• x Driven x
• Intro
• What drives your daily or monthly work.
• Value Objects
• Treated in Domain Driven Design
• Also more concisely in "Refactoring" as "Data Clumps"
• https://learning.oreilly.com/library/view/refactoring-improving-the/9780134757681/ch03.xhtml#ch03lev1sec10
• Coupling question
• Building an interface just for the sake of building an interface
• Talked about the usefulness and when to use and not use an interface
• It is cheap to extract so what is the reason to make them unnessecarily
• Stringly typed interfaces
• Open API contract first
• Contract is outside the code so does not get accidently changed
• Service POJO is generated from Open API
• First thing that happens is a conversion from the POJO to a Domain Object
• (Immutable) Domain Object has the validation
• Each Domain Object has invariants and will throw and exception if attempting to construct an invalid object
• Validation code is concentrated into the Domain Objects, not strewn about
• Disadvantages
• Changing the rules can expose issues with previously stored data
• Example changing a business rule that will make a newly required field
• There will be a problem loading the previously saved fields.
• Just be careful ;-)
• DRY 
• What is too dry
• Rule of three
• Is code that looks the same really the same?
• maybe/maybe not
• Summing the budget and the audience is not the same.
• How do you round the audience members?
• Splitting the domain object
• In three parts
• ID - invented key or perhaps multi-part 
• guid
• or guid + userId
• validated at ID construction time
• don't cross the streams ;-)
• Data - User controllable data
• MetaData - System created data
• Insert - xData comes in and is validated - return ID
• Update - .... something something something.
• Only need the parts you need.
• Immutable grass is what I need
• it doesn't grow so I don't need to waste time cutting it.