feat(gradle/manager): add support for Kotlin objects in buildSrc files

[Churro]

Changes

• Adds functionality to parse variables and dependencies in Kotlin's object { ... } declarations.
• This PR enables out-of-the-box parsing of *.kt files in the buildSrc folder
• The gradle parser now also supports local variables. If used in within an understood (object { ... }, mapOf, ...) hierarchy, renovate preferrably resolve variables in the local scope

Example:

object Foo {
  object Versions {
    const val nanoHttp = "2.3.1"
  }
  const val nanoHttp = "org.nanohttpd:nanohttpd-webserver:${Versions.nanoHttp}"
}

Implementation Notes

• Kotlin source files are parsed twice since objects may cross-reference each other in different files
  • The 1st pass extracts all variables + resolvable dependencies. The 2nd pass is needed for dependencies that rely on version definitions from different files (maybe even residing in subfolders)
  • The gradle manager does dep deduplication in the post processing of extractAllPackageFiles() in extract.ts, so ultimately deps are extracted only once
• Variables extracted from Kotlin files are considered global, i.e., added to the / scope. This is needed because a variable X defined in buildSrc/some/file.kt can be referenced from any .gradle or .gradle.kts build file.

Context

• Closes multimodule gradle (kotlin) with versions defined as constants in buildSrc #5480
• Closes Renovate doesn't scans the latest version based on gradle multi module project using gradle.kts #12397
  • Reproduction repo: https://github.com/renovate-demo/12397-Renovate-kotlin/pulls
• Closes Support scan buildSrc's Dependencies? #13295
  • Reproduction repo: https://github.com/renovate-demo/13295-JetpackComposeSample/pulls
• Related to Support for Gradle composite builds #9410

Documentation (please check one with an [x])

• I have updated the documentation, or
• No documentation update is required

How I've tested my work (please select one)

I have verified these changes via:

• Code inspection only, or
• Newly added/modified unit tests, or
• No unit tests but ran on a real repository, or
• Both unit tests + ran on a real repository

Test scenarios

1. Simple, standard case
   • Nested objects referencing variables that were defined beforehand
     • https://github.com/renovate-demo/Bandhook-Kotlin/blob/master/buildSrc/src/main/java/Config.kt
       -> https://github.com/renovate-demo/Bandhook-Kotlin/pulls
   • object Versions { ... } defined twice in different scope
     • https://github.com/renovate-demo/Shuttle/blob/dev/buildSrc/src/main/kotlin/dependencies/Dependencies.kt#L80-L92 -> https://github.com/renovate-demo/Shuttle/pulls
2. Variables defined in object are then reused in regular .gradle / .gradle.kts files
   • https://github.com/renovate-demo/13295-JetpackComposeSample/blob/master/build.gradle.kts -> https://github.com/renovate-demo/13295-JetpackComposeSample/pulls
3. Variable with version is defined after dependencies or in a different file than the dependency itself
   • https://github.com/renovate-demo/retrofit-graphql/blob/develop/buildSrc/src/main/java/co/anitrend/retrofit/graphql/buildSrc/Libraries.kt -> https://github.com/renovate-demo/retrofit-graphql/pulls

[AlvaroZapp]

Hi! I need this feature, do you know when it will be released?

[zharinov]

LGTM except one suggestion

[renovate-release]

🎉 This PR is included in version 35.78.0 🎉

The release is available on:

• GitHub release
• 35.78.0

Your semantic-release bot 📦🚀

[hoc081098]

Nice 👍 . I just noticed this when renovate bot creating many PRs 😁

[AlvaroZapp]

Hi!

I'm trying running renovate and I'm experiencing a problem with lists, it's not recognizing them:

val core = mutableListOf<String>().apply {
        add("com.google.android.material:material:$support_material")
        add("androidx.lifecycle:lifecycle-reactivestreams-ktx:$vlifecycle")
        add("androidx.lifecycle:lifecycle-livedata-ktx:$vlifecycle")
        add("androidx.lifecycle:lifecycle-runtime-ktx:$vlifecycle")
        add("androidx.core:core-ktx:$ktx_core")
}

dependencies {
    CoreConstant.core.forEach { api(it) }
}