Achieve SOLID Design in Go

Published: 2019-07-30

The following information is a compilation of Wikipedia and the 2016 speech by Dave Cheney (link at the bottom). If I am missing anything or have the wrong idea please message me.

Single responsibility principle

A class should only have a single responsibility, that is, only changes to one part of the software's specification should be able to affect the specification of the class.

• Don't use "Catch all" packages.
• Use "small, sharp tools" combined to tackle a larger task (UNIX philosophy)

Open-closed principle

"Software entities ... should be open for extension, but closed for modification." - Bertrand Meyer

Liskov substitution principle

"Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program." (See also design by contract.)

• Use Interfaces not concrete types
• Simple Implementation
• Common behavior

"Require no more, promise no less" - Jim Weirich

Interface segregation principle

More specific interfaces are better than a few general-purpose interfaces.

"Clients should not be forced to depend on methods they do not use." - Robert C. Martin

Functions and methods should only depend on the behavior they need.

• Isolate functions
• Small, single operation functions are best
• Accept interfaces, return structs

Dependency inversion principle

One should "depend upon abstractions, not concretions."

• Keep the package tree small and wide
• Avoid packages that depend upon other packages
• Third party packages may depend on other third party packages, etc.
• Less imports the better

Speech by Dave Cheney

Watch on YouTube