realm
Rule Request: `explicit_default_argument`
New Issue Checklist
- [x] Updated SwiftLint to the latest version
- [x] I searched for existing GitHub issues
New rule request
I would like to propose a new rule explicit_default_argument which would trigger a violation if an argument passed to a function or initializer matches the default value provided by the function (or init).
Given the following code:
struct Foo {
let bar: Bool
let baz: String
init(bar: Boo, baz: String = "") { ... }
func doSomething(arg: Bool = true, arg2: String = "", arg3: Float = 0.0) { ... }
}
When calling:
let foo = Foo(bar: false, baz: "")
foo.doSomething(arg: true, arg2: "", arg3: 0.0)
Would trigger violations in both lines as they are called with the same values as their defaults. Calling Foo(bar: false, baz: "baz") would not trigger the rule.
This allows for cleaner, more concise code on the call site, especially if there are many default parameters.
let foo = Foo(bar: false)
foo.doSomething()
Should the rule be configurable, if so what parameters should be configurable?
If any, I suggest adding two params, for excluding initializers and excluding functions, both set to false by default.
Should the rule be opt-in or enabled by default? Why?
My suggestion is to set the rule as opt-in. It's a style enhancement, not a functional one.
This requires to implement an Analyzer rule, because the rule needs to access the method/initializer declaration from the call-side to figure out the default parameter values. This is impossible on a syntax-level only.
