Rules for software designs

• These can be contentious, every one has their own set, and some have a following (sometimes cultist)

• There are not one set to rule them all, each have trade offs, some might work well in some domain but not in others

  • Nothing is perfect

• this is just a list of some of the general rules

Kent Beck

The list:

• Runs all the tests

• Has no duplicated logic. Be wary of hidden duplication like parallel class hierarchies

• States every intention important to the programmer

• Has the fewest possible classes and methods

https://martinfowler.com/bliki/BeckDesignRules.html

Copeland

The list:

• is well-covered by passing tests.

• has no abstractions not directly needed by the program.

• has unambiguous behavior.

  • the less ambiguous the code’s behavior is, the better chance we have of successfully changing it

  • this might mean writing more code or being more explicit, or even duplicating things here and there

• requires the fewest number of concepts

  • To understand what code will actually do, we need to understand not only the domain, but also all of the concepts involved in that code

  • the more concepts exist in a design, the harder that design will be to understand.

https://naildrivin5.com/blog/2019/07/25/four-better-rules-for-software-design.html

• Design is About Balancing Cohesion and Coupling

  • Not blindly following principles

Get shit done (lean/agile)

faster, better, cheaper than anyone.

1. Develop for today ( You are not gonna need it - YANGNI )

2. Do not forget tomorrow ( Do not Repeat Yourself )

3. Totally ignore days after tomorrow ( things change every month )

4. Fastest finger first wins

5. When the quality is high enough ( happy customer )

6. Tomorrow is taken care of ( build for immediate future )

7. Smallest Code wins

8. Given Tomorrow people would be able to understand it - ( Principle of Least Astonishment )

9. Code is provably correct ( CHC )

10. Developers gets judged on:

11. Less experience - how fast code and how much with quality

12. Higher experience - how much code they removed from existing source code base

13. Only measure of code compaction is - Kolmogorov complexity

14. Code complexity measures like Cyclomatic are dangerously modular ( Assembly Line Complexity )

in a product company, any product company, really, no one cares about the lines of code that have been written

Others

• https://www.ics.uci.edu/~emilyo/SimSE/se_rules.html

• https://www.geeksforgeeks.org/20-golden-rules-to-learn-in-software-development/