Is it possible to get the root path of the project (as a string) in commonTest?

# multiplatform

[Justin]

Is it possible to get the root path of the project (as a string) in commonTest?

[basher]

In a gradle file or in Kotlin?

[basher]

i guess if you're asking about commonTest, you mean Kotlin

[Justin]

Basically I need to be able to access the files in project/src/commonTest/resources/

[Justin]

i have file reader actuals implemented in jvm/ios/js

[Justin]

in jvm i can do
val filePath: String = System.getProperty("user.dir") + "/src/commonTest/resources/" + fileName

[Justin]

but i can't do that in js or ios obviously

[basher]

In your build, you can codegen a Kotlin file that has that constant (in an object or something). You'd spit out that file in your build dir somewhere and then add that folder to your commonTest sourceSet

[Justin]

is that complicated to do?

[Justin]

or relatedly, is it possible to make values declared in build.gradle.kts available in kotlin sources?

[basher]

I believe this is generally the way it's done. It's basically what android gradle plugin does

[basher]

with BuildConfig. one sec. sample code coming

[Justin]

ok sweet thanks!

[basher]

afterEvaluate {
    tasks.register("generateTheCodes") {
        def packageRoot = file("build/mycodgen/kotlin/com/<package-path>")
        def buildConfigFile = new File(packageRoot, "BuildConfig.kt")
        outputs.file(buildConfigFile)

        doLast {
            // make the directory tree
            mkdir packageRoot

            buildConfigFile.text = ""

            buildConfigFile << """package <your-package>
              |object MyBuildConfig {
              |    const val resourcesPath = ${file("src/commonTest/resources").path}              
              |}
            """.stripMargin().stripIndent()
        }
    }

    // Include this in our source sets
    kotlin.sourceSets.named("commonTest") {
        kotlin.srcDirs += uidsRoot
    }
    // Ensure this runs before any compile task
    tasks.withType(AbstractCompile.class).each {
        it.configure {
            dependsOn 'generateTheCodes'
        }
    }
}

[basher]

this creates a task called generateTheCodes which outputs a .kt file that has an object in it, then at the end we add it to commonTest sources and add it to the task graph (with a bit of a broad brush, but should work fine)

[Justin]

you're the man

[basher]

there are some things that you'll have to adjust for your case like the package paths and all that, but hopefully this gives a good start

[Justin]

let me try it out

[Justin]

thank you!

[basher]

codegen is great, once you get the hang of it. you can save yourself a lot of time making it part of your teams workflow to automate common classes, etc.

[Justin]

oh definitely. i'm just new-ish to kotlin

[Justin]

but it's served well on other platforms

[basher]

yeah no worries 🙂

[Justin]

hmm packageRoot should point to what exactly

[basher]

com/mycompany/mylibrary/

[Justin]

inside of the build folder though?

[Justin]

or is the build meaningless in the sample

[basher]

oh yeah so inside the build folder, pick a name that makes sense for your root for this codegen

[basher]

like build/mybuildconfig

[Justin]

gotcha

[basher]

and then source will be build/mybuildconfig/com/mycompany/mypackage/

[basher]

basically mirroring package/folder structure in your lib

[Justin]

ok trying that now

[Justin]

last q: what is uidsRoot supposed to point to?

[Justin]

i guess packageRoot

[basher]

oh yeah sorry. i was adapting some personal code and forgot to fix that var name

[basher]

uidsRoot is `build/mybuildconfig`` in this case

[basher]

so not package root

[Justin]

@basher It's almost working!

The `BuildConfig.kt`gets created in build/<package>, but I still can't reference BuildConfig.resourcesPath from the files in commonTest (suggesting that something's not working with adding the dir to the sourceset)?

[basher]

does the BuildConfig.kt have the right package declaration at the top?

[basher]

and you're adding bulid/mybuildconfig to commonTest right? not the full path?

[Justin]

yea it does. this is what i got

[Justin]

afterEvaluate {
    val generateBuildConfig = tasks.register("generateBuildConfig") {
        val packageRoot = file("build/codegen/kotlin/com/n8p6/enkounter/")
        val buildConfigFile = File(packageRoot,"BuildConfig.kt")
        outputs.file(buildConfigFile)

        doLast {
            mkdir(packageRoot)

            buildConfigFile.writeText("""
                package com.n8p6.enkounter
                
                object BuildConfig {
                    const val resourcesPath: String = "${file("src/commonTest/kotlin/com/n8p6/enkounter/resources").path}"
                }
                """.trimMargin().trimIndent()
            )
        }
    }

    kotlin.sourceSets.named("commonTest") {
        kotlin.srcDirs += file("build/codegen/kotlin/com/n8p6/enkounter")
    }

    tasks.withType<AbstractCompile>().forEach {
        it.dependsOn(generateBuildConfig)
    }
}

[basher]

one thing to be careful of is that if you have an Android target, Android also makes an object called BuildConfig (may want to consider a prefix)

[Justin]

ah i don't

[Justin]

but might be worth changing regardless just to be safe

[basher]

kotlin.srcDirs += file("build/codegen/kotlin/com/n8p6/enkounter") should be kotlin.srcDirs += file("build/codegen")

[Justin]

ohhh

[Justin]

i see what you meant

[Justin]

let me try that

[basher]

🙂

[Justin]

finally got it with commonTest.kotlin.setSrcDirs(commonTest.kotlin.srcDirs + "build/codegen")

[Justin]

thank you so much for your help @basher!

[basher]

🎉 np!

[russhwolf]

FYI there's a library BuildKonfig that does some of this work for you if you want the configuration to feel more like an Android project. https://github.com/yshrsmz/BuildKonfig

[basher]

Ooh nice!