Heuristic for determining which tests to run

EndToEndTestScopeAnalyzer.kt

fun getTestFilesForChangedFeatureModules(projectDir: File, testDir: File, featureModulesNames: Set<String>): Set<String> {
  val testFilesToRun = HashSet<String>()
  testDir.walkTopDown().filter { !it.isDirectory }.forEach { testFile ->
    val modulesRelevantToTests = analyzeEndToEndTestFile(testFile.absolutePath)
    val shouldRunTests = modulesRelevantToTests.intersect(featureModulesNames).any()
    if (shouldRunTests) {
      val testPattern = testFile.relativeTo(projectDir).path
        .substringAfter("java/")
        .replace('/', '.')
        .removeSuffix(".kt")
      testFilesToRun.add(testPattern)
    }
  }
  return testFilesToRun
}

fun analyzeEndToEndTestFile(filename: String): Set<String> {
  val importPrefix = "com.wf.test.actions"
  val parsed = KotlinGrammarAntlrKotlinParser.parseKotlinFile(AstSource.File(filename)) as DefaultAstNode

  return (parsed.children.filter("importList").firstOrNull() as? DefaultAstNode)
    ?.children
    ?.filter("importHeader")
    ?.asSequence()
    ?.filterIsInstance<DefaultAstNode>()
    ?.flatMap { it.children.filter("identifier").filterIsInstance<DefaultAstNode>() }
    ?.map { node -> extractTerminals(node).joinToString("") { it.text } }
    ?.filter { it.startsWith(importPrefix) }
    ?.map { it.removePrefix("$importPrefix.").substringBefore('.') }
    ?.toSet()
    .orEmpty()
} 

fun extractTerminals(node: DefaultAstNode): List<DefaultAstTerminal> =
    node.children
      .filterIsInstance<DefaultAstNode>()
      .flatMap(::extractTerminals) +
      node.children.filterIsInstance<DefaultAstTerminal>()