Add warning/error for unsupported sbt 0.x and 2.x versions (#281)

Author: Malax

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## [Unreleased]
 
+* Add error for unsupported sbt `2.x` versions. ([#281](https://github.com/heroku/heroku-buildpack-scala/pull/281))
+* Add warning for unsupported sbt `0.x` versions. ([#281](https://github.com/heroku/heroku-buildpack-scala/pull/281))
 * Remove automatic deletion of `project/play-fork-run.sbt` files. Maintainers of legacy apps can consult the PR description for background and how to fix their project in the unlikely case it's necessary. ([#280](https://github.com/heroku/heroku-buildpack-scala/pull/280))
 * Deprecate Scala buildpack configuration via system.properties. A warning is now shown when Scala buildpack configuration properties (like `sbt.clean`, `sbt.project`, etc.) are detected in system.properties. Use environment variables instead. This does not affect `java.runtime.version` which remains supported. ([#279](https://github.com/heroku/heroku-buildpack-scala/pull/279))
 * Remove partial CNB functionality. ([#276](https://github.com/heroku/heroku-buildpack-scala/pull/276))

bin/compile

@@ -90,23 +90,68 @@ for DIR in ${CACHED_DIRS}; do
 	cache_copy "${DIR}" "${CACHE_DIR}" "${BUILD_DIR}"
 done
 
-# these are preliminary checks. actual version check happens below when attempting to download sbt boot.properties
-if ! test -e project/build.properties; then
+sbt_version="$(java_properties::get "${BUILD_DIR}/project/build.properties" "sbt.version")"
+metrics::set_string "sbt_version" "${sbt_version:-"unknown"}"
+
+if [[ -z "${sbt_version}" ]]; then
 	output::error <<-EOF
-		Your scala project must include project/build.properties and define sbt.version
+		Error: sbt version cannot be determined.
+
+		As part of your build definition you must specify the version of sbt that
+		your build uses. This ensures consistent results across different environments.
+
+		To fix this issue, create a file named project/build.properties that specifies
+		the sbt version as follows:
+
+		    sbt.version=1.11.7
+
+		For more information, see:
+		https://www.scala-sbt.org/1.x/docs/Basic-Def.html#Specifying+the+sbt+version
 	EOF
 
 	exit 1
 fi
 
-if ! (has_supported_sbt_version "${BUILD_DIR}" || has_supported_sbt_1_version "${BUILD_DIR}"); then
+case "${sbt_version}" in
+0.*)
+	output::warning <<-EOF
+		Warning: Unsupported sbt version detected.
+
+		This buildpack does not officially support sbt ${sbt_version}. You are using
+		an end-of-life version that no longer receives security updates or bug fixes.
+		Support for sbt 0.x was ended by the upstream sbt project on November 30, 2018.
+
+		Please upgrade to sbt 1.x for active support.
+
+		The buildpack will attempt to build your application, but compatibility
+		is not guaranteed and may break at any time.
+
+		For more information:
+		- https://web.archive.org/web/20210918065807/https://www.lightbend.com/blog/scala-sbt-127-patchnotes
+
+		Upgrade guide:
+		- https://www.scala-sbt.org/1.x/docs/Migrating-from-sbt-013x.html
+	EOF
+	;;
+2.*)
 	output::error <<-EOF
-		You have defined an unsupported sbt.version in project/build.properties
-		For sbt 0.x you must use a version >= 0.11, for sbt 1.x you must use a version >= 1.1
+		Error: Unsupported sbt version detected.
+
+		This buildpack does not currently support sbt 2.x. You are using sbt ${sbt_version}.
+
+		Support for sbt 2.x will be added in a future buildpack release. In the
+		meantime, please use the latest stable sbt 1.x version for your deployments.
+
+		To continue, update project/build.properties to use sbt 1.x.
+
+		For more information:
+		- Latest sbt 1.x releases: https://github.com/sbt/sbt/releases
+		- sbt 2.x changes: https://www.scala-sbt.org/2.x/docs/en/changes/sbt-2.0-change-summary.html
 	EOF
 
 	exit 1
-fi
+	;;
+esac
 
 if has_old_preset_sbt_opts; then
 	output::warning <<-EOF
@@ -123,8 +168,6 @@ if has_old_preset_sbt_opts; then
 	EOF
 fi
 
-SBT_VERSION="$(get_supported_sbt_version "${BUILD_DIR}")"
-
 if [[ -n "${SBT_PROJECT}" ]]; then
 	SBT_TASKS="${SBT_PROJECT}/compile ${SBT_PROJECT}/stage"
 else
@@ -145,19 +188,22 @@ fi
 install_sbt_extras "${BUILDPACK_DIR}/opt" "${SBT_BINDIR}"
 
 # copy in heroku sbt plugin
-if has_supported_sbt_1_version "${BUILD_DIR}"; then
+case "${sbt_version}" in
+1.*)
 	HEROKU_PLUGIN="HerokuBuildpackPlugin_sbt1.scala"
-else
+	;;
+*)
 	HEROKU_PLUGIN="HerokuBuildpackPlugin.scala"
-fi
+	;;
+esac
+
 mkdir -p "${SBT_USER_HOME}/plugins"
 rm -f "${SBT_USER_HOME}/plugins/HerokuPlugin.scala"               # remove the old ambiguously named plugin
 rm -f "${SBT_USER_HOME}/plugins/HerokuBuildpackPlugin_sbt1.scala" # remove the old poorly named plugin
 rm -f "${SBT_USER_HOME}/plugins/HerokuBuildpackPlugin.scala"      # remove the old plugin
 cp -p "${BUILDPACK_DIR}/opt/${HEROKU_PLUGIN}" "${SBT_USER_HOME}/plugins/HerokuBuildpackPlugin.scala"
 
 # Collect metrics
-metrics::set_string "sbt_version" "${SBT_VERSION:-unknown}"
 
 if is_sbt_native_packager "${BUILD_DIR}"; then
 	metrics::set_raw "uses_sbt_native_packager" "true"

lib/common.sh

@@ -2,9 +2,6 @@
 
 set -euo pipefail
 
-SBT_0_VERSION_PATTERN='sbt\.version=\(0\.1[1-3]\.[0-9]\+\(-[a-zA-Z0-9_]\+\)*\)$'
-SBT_1_VERSION_PATTERN='sbt\.version=\(1\.[1-9][0-9]*\.[0-9]\+\(-[a-zA-Z0-9_]\+\)*\)$'
-
 is_play() {
 	local app_dir="${1}"
 
@@ -32,44 +29,6 @@ is_sbt_native_packager() {
 	fi
 }
 
-get_supported_sbt_version() {
-	local ctx_dir="${1}"
-	local sbt_version_pattern="${2:-${SBT_0_VERSION_PATTERN}}"
-	if test -e "${ctx_dir}/project/build.properties"; then
-		sbt_version_line="$(grep -P '[ \t]*sbt\.version[ \t]*=' "${ctx_dir}"/project/build.properties | sed -E -e 's/[ \t\r\n]//g' || true)"
-		sbt_version="$(expr "${sbt_version_line}" : "${sbt_version_pattern}")"
-		if [[ "${sbt_version}" != 0 ]]; then
-			echo "${sbt_version}"
-		else
-			echo ""
-		fi
-	else
-		echo ""
-	fi
-}
-
-has_supported_sbt_version() {
-	local ctx_dir="${1}"
-	local supported_version
-	supported_version="$(get_supported_sbt_version "${ctx_dir}" "${SBT_0_VERSION_PATTERN}")"
-	if [[ -n "${supported_version}" ]]; then
-		return 0
-	else
-		return 1
-	fi
-}
-
-has_supported_sbt_1_version() {
-	local ctx_dir="${1}"
-	local supported_version
-	supported_version="$(get_supported_sbt_version "${ctx_dir}" "${SBT_1_VERSION_PATTERN}")"
-	if [[ -n "${supported_version}" ]]; then
-		return 0
-	else
-		return 1
-	fi
-}
-
 has_old_preset_sbt_opts() {
 	if [[ "${SBT_OPTS:-}" = "-Xmx384m -Xss512k -XX:+UseCompressedOops" ]]; then
 		return 0

test/spec/fixtures/repos/sbt-0.13.18-minimal-with-native-packager/.gitignore

@@ -0,0 +1,3 @@
+target/
+.bsp
+.idea

test/spec/fixtures/repos/sbt-0.13.18-minimal-with-native-packager/build.sbt

@@ -0,0 +1,11 @@
+name := "sbt-1.11.7-minimal-with-native-packager"
+
+scalaVersion := "2.13.17"
+
+libraryDependencies ++= Seq(
+	"dev.zio" %% "zio-http" % "3.5.1"
+)
+
+import NativePackagerKeys._
+
+packageArchetype.java_application

test/spec/fixtures/repos/sbt-0.13.18-minimal-with-native-packager/project/build.properties

@@ -0,0 +1 @@
+sbt.version=0.13.18

test/spec/fixtures/repos/sbt-0.13.18-minimal-with-native-packager/project/plugins.sbt

@@ -0,0 +1,2 @@
+addSbtPlugin("com.typesafe.sbt" % "sbt-native-packager" % "0.7.5-RC2")
+

test/spec/fixtures/repos/sbt-0.13.18-minimal-with-native-packager/src/main/scala/com/heroku/App.scala

@@ -0,0 +1,15 @@
+package com.heroku
+
+import zio._
+import zio.http._
+
+object App extends ZIOAppDefault {
+  private val routes = Routes(
+    Method.GET / Root -> handler(Response.text("Hello from Scala!"))
+  )
+
+  def run = for {
+    port <- System.env("PORT").map(_.flatMap(_.toIntOption).getOrElse(8080))
+    _ <- Server.serve(routes).provide(Server.defaultWithPort(port))
+  } yield ()
+}

test/spec/fixtures/repos/sbt-0.13.18-minimal-with-native-packager/system.properties

@@ -0,0 +1 @@
+java.runtime.version=11

test/spec/fixtures/repos/sbt-1.11.7-minimal-with-native-packager/.gitignore

@@ -0,0 +1,3 @@
+target/
+.bsp
+.idea