android_build_bisect.main.kts

#!/usr/bin/env kotlin
@file:DependsOn("com.github.ajalt.clikt:clikt-jvm:3.5.2")
@file:OptIn(ExperimentalTime::class)

import com.github.ajalt.clikt.core.CliktCommand
import com.github.ajalt.clikt.parameters.options.option
import com.github.ajalt.clikt.parameters.options.required
import java.io.File
import java.security.MessageDigest
import kotlin.time.ExperimentalTime
import kotlin.time.measureTime

class App : CliktCommand() {

  private val bad by option().required()
  private val good by option().required()
  
  override fun run() {
    val commitsBetween = executeCommand("git", "rev-list", "--ancestry-path", "$good..$bad")
      .filter(String::isNotEmpty)
      .reversed()
    val output = File("apks")
      .also { it.mkdir() }
    commitsBetween
      .forEachIndexed { index, sha ->
        println("checking out $index:$sha")
        val apk = File("app/build/outputs/apk/debug/app-debug.apk")
        apk.delete()
        measureTime {
          executeCommand("git", "checkout", sha)
          executeCommand("./gradlew", "app:assembleDebug")
          apk.copyTo(File(output, "$index-$sha.apk"))
        }.also { println("took $it") }
      }

    deleteDupes(output)
  }

  private fun deleteDupes(output: File) {
    output.listFiles()!!.toList()
      .groupBy {
        calculateFileHash(it)
      }
      .forEach { (_, files) ->
        if (files.size > 1) {
          files.drop(1).forEach {
            it.delete()
          }
        }
      }
  }

  private fun calculateFileHash(file: File): String {
    val md = MessageDigest.getInstance("SHA-256")
    val digest = md.digest(file.readBytes())
    return digest.joinToString("") { "%02x".format(it) }
  }

  private fun executeCommand(vararg command: String): List<String> {
    return Runtime
      .getRuntime()
      .exec(command)
      .inputStream
      .bufferedReader()
      .use { it.readLines() }
  }
}
App().main(args)