Define FunctionSignature

[BraisGabin]

This class is a helper that I need to implement #4148. I moved it outside that PR becase the code is complex and have entity by itself.

I'm not very happy with all the naming that I'm using so any suggestion there is that regard is more than welcome.

[codecov]

Codecov Report

Merging #4176 (d7974ef) into main (9aa0407) will decrease coverage by 0.00%.
The diff coverage is 87.87%.

@@             Coverage Diff              @@
##               main    #4176      +/-   ##
============================================
- Coverage     84.26%   84.25%   -0.01%     
+ Complexity     3245     3238       -7     
============================================
  Files           468      469       +1     
  Lines         10178    10199      +21     
  Branches       1787     1792       +5     
============================================
+ Hits           8576     8593      +17     
  Misses          658      658              
- Partials        944      948       +4     

Impacted Files	Coverage Δ
.../gitlab/arturbosch/detekt/rules/MethodSignature.kt	70.00% <ø> (ø)
...in/io/github/detekt/tooling/api/FunctionMatcher.kt	86.20% <86.20%> (ø)
...turbosch/detekt/rules/style/ForbiddenMethodCall.kt	88.57% <100.00%> (+0.76%)	⬆️
...rbosch/detekt/rules/style/ObjectLiteralToLambda.kt	83.78% <0.00%> (-3.40%)	⬇️

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[BraisGabin]

This is a matrix of cases. Given a list of MethodSignatures and a list of function declarations I want to say if it should match or no. And then check all those cases and see that it's correct.

Do you know any better way to write this and no make it a maintainance hell?

[chao2zhang]

What I can think of is to give each functions element a specify name, such as ToStringNoArg, ToStringOneArg, ToStringTwoArgs, CompareNoArg, CompareOneArg, and CompareTwoArgs.

This does prevent magic numbers being used, but the maintenance cost is still there.

[BraisGabin]

I had that. The problem is that the readability is a bit worst:

ToStringNoArg to false, // fun toString()
ToStringOneArg to false, // fun toString(hello: String)
ToStringTwoArgs to false, // fun toString(hello: String, world: Int)
CompareNoArg to false, // fun compare()
CompareOneArg to false, // fun compare(hello: String)
CompareTwoArgs to false, // fun compare(hello: String, world: Int)

vs

functions[0] to false, // fun toString()
functions[1] to false, // fun toString(hello: String)
functions[2] to false, // fun toString(hello: String, world: Int)
functions[3] to false, // fun compare()
functions[4] to false, // fun compare(hello: String)
functions[5] to false, // fun compare(hello: String, world: Int)

The second one keeps the columns aligned so it's a bit easier to read and modify. Usually I don't care about alignment and I would vote against comments that are far too easy to get outdated but in this case I'm not that sure. Do you think the first is better?

[chao2zhang]

I like the former one. The second has the horizontal alignment but I agree with "Clean code" that it shouldn't matter - Once we have more than 10 items, we do not get columns fully aligned anymore.

Additionally, I don't think the comments become necessary in the former case.

[chao2zhang]

I like FunctionSignature. If we want to emphasize its core functionality, we can call it FunctionMatcher.

[chao2zhang]

What I can think of is to give each functions element a specify name, such as ToStringNoArg, ToStringOneArg, ToStringTwoArgs, CompareNoArg, CompareOneArg, and CompareTwoArgs.

This does prevent magic numbers being used, but the maintenance cost is still there.