From d0957b4444c28cf1721b8bdec2e9c81b22c3c573 Mon Sep 17 00:00:00 2001
From: Khemraj Rathore <khemraj.rathore@privado.ai>
Date: Tue, 31 Dec 2024 16:11:08 +0530
Subject: [PATCH] add ast-gen in ruby

---
 joern-cli/frontends/rubysrc2cpg/build.sbt | 46 +++++++++++++++++++----
 1 file changed, 39 insertions(+), 7 deletions(-)

diff --git a/joern-cli/frontends/rubysrc2cpg/build.sbt b/joern-cli/frontends/rubysrc2cpg/build.sbt
index 0fd0eb2aa7a9..1376a346fee1 100644
--- a/joern-cli/frontends/rubysrc2cpg/build.sbt
+++ b/joern-cli/frontends/rubysrc2cpg/build.sbt
@@ -28,19 +28,51 @@ libraryDependencies ++= Seq(
   "org.jruby"      % "jruby-complete" % Versions.jRuby
 )
 
-enablePlugins(JavaAppPackaging, LauncherJarPlugin)
-
-libraryDependencies ++= Seq(
-  "io.shiftleft"  %% "codepropertygraph" % Versions.cpg,
-  "org.scalatest" %% "scalatest"         % Versions.scalatest % Test
-)
-
 enablePlugins(JavaAppPackaging, LauncherJarPlugin, Antlr4Plugin)
 
 Antlr4 / antlr4Version    := Versions.antlr
 Antlr4 / antlr4GenVisitor := true
 Antlr4 / javaSource       := (Compile / sourceManaged).value
 
+lazy val astGenVersion = settingKey[String]("`ruby_ast_gen` version")
+astGenVersion := appProperties.value.getString("rubysrc2cpg.ruby_ast_gen_version")
+
+lazy val astGenDlUrl = settingKey[String]("astgen download url")
+astGenDlUrl := s"https://github.com/joernio/ruby_ast_gen/releases/download/v${astGenVersion.value}/"
+
+def hasCompatibleAstGenVersion(astGenBaseDir: File, astGenVersion: String): Boolean = {
+  val versionFile = astGenBaseDir / "lib" / "ruby_ast_gen" / "version.rb"
+  if (!versionFile.exists) return false
+  val versionPattern = "VERSION = \"([0-9]+\\.[0-9]+\\.[0-9]+)\"".r
+  versionPattern.findFirstIn(IO.read(versionFile)) match {
+    case Some(versionString) =>
+      // Regex group matching doesn't appear to work in SBT
+      val version = versionString.stripPrefix("VERSION = \"").stripSuffix("\"")
+      version == astGenVersion
+    case _ => false
+  }
+}
+
+lazy val astGenResourceTask = taskKey[Seq[File]](s"Download `ruby_ast_gen` and package this under `resources`")
+astGenResourceTask := {
+  val targetDir           = baseDirectory.value / "src" / "main" / "resources"
+  val gemName             = s"ruby_ast_gen_v${astGenVersion.value}.zip"
+  val compressGemPath     = targetDir / gemName
+  val unpackedGemFullPath = targetDir / gemName.stripSuffix(s"_v${astGenVersion.value}.zip")
+  if (!hasCompatibleAstGenVersion(unpackedGemFullPath, astGenVersion.value)) {
+    if (unpackedGemFullPath.exists()) IO.delete(unpackedGemFullPath)
+    val url = s"${astGenDlUrl.value}$gemName"
+    sbt.io.Using.urlInputStream(new URI(url).toURL) { inputStream =>
+      sbt.IO.transfer(inputStream, compressGemPath)
+    }
+    IO.unzip(compressGemPath, unpackedGemFullPath)
+    IO.delete(compressGemPath)
+  }
+  (unpackedGemFullPath ** "*").get.filter(_.isFile)
+}
+
+Compile / resourceGenerators += astGenResourceTask
+
 lazy val joernTypeStubsDlUrl = settingKey[String]("joern_type_stubs download url")
 joernTypeStubsDlUrl := s"https://github.com/joernio/joern-type-stubs/releases/download/v${joernTypeStubsVersion.value}/"