Discussion: `final` modifier convention in method arguments

final modifier is used in local variables or class fields when it could be immutable. However, conventionally, we didn’t use the final modifier in method arguments. CONTRIBUTING.md or checkstyle doesn’t mention or force about it. Sometimes it confuses contributors who contribute Armeria for the first time when writing a method.

I want to hear folks’ opinions about the final modifier convention.

• Add final modifier in method arguments?

  void foo(final int a, final String b) { ... }
  

  • Pros: Compiler force immutable.
  • Cons: Method signature could be too long.
• No final modifier in method arguments + checkstyle
  • Pros: Method signature is cleaner, and we don’t have to review anymore.
  • Cons: Flexibility 👎. Sometimes, he/she might want to add final to force it immutable.
• No final modifier in method arguments + clarify the convention in the CONTRIBUTING.md
  • Pros: Flexibility 👍. The method signature is cleaner.
  • Cons: No validation in the build process.

Additionally, modern IDE like IntelliJ draws an underline in a local variable if it is mutable. Remove the final modifier for the local variable to reduce verbosely?

[trustin]

For this library, I agree with @anuraaga . I vote for no final in method args/local + checkstyle.

+1

IntelliJ automatically highlights a mutable variable/parameter, so I’m happy without final - https://intellij-support.jetbrains.com/hc/en-us/community/posts/360000395439/comments/360000082320

[codefromthecrypt]

(ps my vote is no final on locals/parameters unless it is somehow clarifying. use the attention of the keyword explicitly rather than the other way around)