Deprecated replaceWith - support in diktat

[orchestr7]

Kotlin has outstanding logic (deprecation scenarios) - library author can help user to fix the code.
Probably in the future, when we will have all information about the project (and new framework)

@Deprecated("Old stuff", ReplaceWith("test2"))

[nulls]

Do you mean support it in diktat with autofix? "replaceWith" doesn't mean replacement 1:1

[orchestr7]

Do you mean support it in diktat with autofix? "replaceWith" doesn't mean replacement 1:1

No, it actually does the logic in 90% of scenarios. IDEA uses it: https://dev.to/mreichelt/the-hidden-kotlin-gem-you-didn-t-think-you-ll-love-deprecations-with-replacewith-3blo

[nulls]

If we will support it as autofix logic -- we will produce irrelevant code in 10% of scenarios.

[orchestr7]

If we will support it as autofix logic -- we will produce irrelevant code in 10% of scenarios.

How IDEA filters out false positives?
They do absolutely the same

[nulls]

Yep, looks like I didn't get properly kotlin.ReplaceWith
Tested locally -- IDEA doesn't check that ReplaceWith.expression is valid (developer is who triggers a replacement in IDEA). But I guess there is the assumption: if ReplaceWith.expression is set, it must be applicable and valid.

Make the following example (inspired by com.pinterest.ktlint.core.KtLint.ExperimentalParams vs com.pinterest.ktlint.core.KtLint.Params)

1. replaceWith is valid

data class ParamsOld(
    val arg1: String,
    val arg2: String,
)

@Deprecated(
    message = "extended params",
    replaceWith = ReplaceWith("this.doLogicNew(ParamsNew(params.arg1, params.arg2, arg3))", imports = ["ParamsNew"])
)
fun doLogicOld(params: ParamsOld, arg3: String) {
    println("${params.arg1} -> ${params.arg2} -> ${arg3}")
}

data class ParamsNew(
    val arg1: String,
    val arg2: String,
    val arg3: String,
)

fun doLogicNew(params: ParamsNew) {
    println("${params.arg1} -> ${params.arg2} -> ${params.arg3}")
}

Usage:

fun test() {
    doLogicOld(ParamsOld("1", "2"), "3")
}

IDEA transforms it to (problem with whitespaces on new line)

fun test() {
    val params = ParamsOld("1", "2")
 doLogicNew(ParamsNew(params.arg1, params.arg2, "3"))
}

2. replaceWith is invalid

// same example as previously, but
@Deprecated(
    message = "extended params",
    replaceWith = ReplaceWith("this.doLogicInvalid(ParamsNew(params.arg1, params.arg2, arg3))", imports = ["ParamsNew"])
)
fun doLogicOld(params: ParamsOld, arg3: String) {
    println("${params.arg1} -> ${params.arg2} -> ${arg3}")
}

IDEA transforms it to (funny, but it doesn't have problem with whitespaces on new line)

fun test() {
    val params = ParamsOld("1", "2")
    this.doLogicInvalid(ParamsNew(params.arg1, params.arg2, "3"))
}

[0x6675636b796f75676974687562]

In response to the previous comment:

But I guess there is the assumption: if ReplaceWith.expression is set, it must be applicable and valid.

Exactly. And if my memory fails me not, there's an equivalent quickfix action in IDEA itself.

Additionally, a user can always switch a particular DiKTat inspection off is they desire so.