ktlint appears to be reading from the File not the String

[auguwu]

This issue is present in only Kotlin/Kotlin (Gradle) file source sets that I know of with the ktlint formatter.

When a source file is changed, the license doesn't reflect the changes and marks the file as an OK state, which should update the license content if it was changed.

A reproduction repository can be seen in auguwu/spotless-kotlin/repro. Just run ./gradlew spotlessApply.

Expected Result

/**
 * some example of license content here
 * Copyright (c) 2023
 */

import kotlin.TODO

fun main(args: Array<String>) {
    println(

        "we do a little" +

            "trolling",
    )

    TODO("this function is a work in progress!")
}

Actual Result

import kotlin.TODO

fun main(args: Array<String>) {
    println(

        "we do a little" +

            "trolling",
    )

    TODO("this function is a work in progress!")
}

• Gradle: 7.6 ~ 8.0.1
• Spotless: 6.14.0 ~ 6.16.0
• Operating System (from uname -a): Linux [redacted] 6.1.12-arch1-1 #1 SMP PREEMPT_DYNAMIC Tue, 14 Feb 2023 22:08:08 +0000 x86_64 GNU/Linux

[nedtwigg]

A workaround is to move the licenseHeaderFile to the bottom of the kotlin block. But this indicates a deeper bug where the ktlint integration is violating Spotless' composability contract. Thanks for reporting, this is a medium-deal bug in the ktlint formatter which we will definitely fix.

[nedtwigg]

This bug is definitely present in the default ktlint version of plugin-gradle 6.16.0.

[nedtwigg]

Fixed in plugin-gradle 7.0.0.BETA4 and plugin-maven 2.44.0.BETA4.