From fc2413f29bc2bb08f78ef368c35483e5f96025b3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johan=20Andr=C3=A9n?= <johan@markatta.com>
Date: Tue, 9 Jan 2018 20:11:14 +0100
Subject: [PATCH] Version checking utility #24030

---
 .../src/test/scala/akka/AkkaVersionSpec.scala | 81 +++++++++++++++++++
 .../src/main/scala/akka/AkkaVersion.scala     | 52 ++++++++++++
 2 files changed, 133 insertions(+)
 create mode 100644 akka-actor-tests/src/test/scala/akka/AkkaVersionSpec.scala
 create mode 100644 akka-actor/src/main/scala/akka/AkkaVersion.scala

diff --git a/akka-actor-tests/src/test/scala/akka/AkkaVersionSpec.scala b/akka-actor-tests/src/test/scala/akka/AkkaVersionSpec.scala
new file mode 100644
index 0000000000..efd561f15c
--- /dev/null
+++ b/akka-actor-tests/src/test/scala/akka/AkkaVersionSpec.scala
@@ -0,0 +1,81 @@
+/**
+ * Copyright (C) 2009-2017 Lightbend Inc. <http://www.lightbend.com>
+ */
+package akka
+
+import org.scalatest.{ Matchers, WordSpec }
+
+class AkkaVersionSpec extends WordSpec with Matchers {
+
+  "The Akka version check" must {
+
+    "succeed if version is ok" in {
+      AkkaVersion.require("AkkaVersionSpec", "2.5.6", "2.5.6")
+      AkkaVersion.require("AkkaVersionSpec", "2.5.6", "2.5.7")
+      AkkaVersion.require("AkkaVersionSpec", "2.5.6", "2.6.0")
+    }
+
+    "succeed if version is RC and ok" in {
+      AkkaVersion.require("AkkaVersionSpec", "2.5.6", "2.5.7-RC10")
+    }
+
+    "fail if version is RC and not ok" in {
+      intercept[UnsupportedAkkaVersion] {
+        AkkaVersion.require("AkkaVersionSpec", "2.5.6", "2.5.6-RC1")
+      }
+    }
+
+    "succeed if version is milestone and ok" in {
+      AkkaVersion.require("AkkaVersionSpec", "2.5.6", "2.5.7-M10")
+    }
+
+    "fail if version is milestone and not ok" in {
+      intercept[UnsupportedAkkaVersion] {
+        AkkaVersion.require("AkkaVersionSpec", "2.5.6", "2.5.6-M1")
+      }
+    }
+
+    "fail if major version is different" in {
+      // because not bincomp
+      intercept[UnsupportedAkkaVersion] {
+        AkkaVersion.require("AkkaVersionSpec", "2.5.6", "3.0.0")
+      }
+      intercept[UnsupportedAkkaVersion] {
+        AkkaVersion.require("AkkaVersionSpec", "2.5.6", "1.0.0")
+      }
+    }
+
+    "fail if minor version is too low" in {
+      intercept[UnsupportedAkkaVersion] {
+        AkkaVersion.require("AkkaVersionSpec", "2.5.6", "2.4.19")
+      }
+    }
+
+    "fail if patch version is too low" in {
+      intercept[UnsupportedAkkaVersion] {
+        AkkaVersion.require("AkkaVersionSpec", "2.5.6", "2.5.5")
+      }
+    }
+
+    "succeed if Akka version is SNAPSHOT" in {
+      AkkaVersion.require("AkkaVersionSpec", "2.5.6", "2.5-SNAPSHOT")
+    }
+
+    "succeed if Akka version is timestamped SNAPSHOT" in {
+      AkkaVersion.require("AkkaVersionSpec", "2.5.6", "2.5-20180109-133700")
+    }
+
+    "silently comply if current version is incomprehensible" in {
+      // because we may want to release with weird numbers for some reason
+      AkkaVersion.require("nonsense", "2.5.6", "nonsense")
+    }
+
+    "fail if fed incomprehensible requirement" in {
+      intercept[IllegalArgumentException] {
+        AkkaVersion.require("AkkaVersionSpec", "nonsense", "2.5.6")
+      }
+    }
+
+  }
+
+}
diff --git a/akka-actor/src/main/scala/akka/AkkaVersion.scala b/akka-actor/src/main/scala/akka/AkkaVersion.scala
new file mode 100644
index 0000000000..cfeb516760
--- /dev/null
+++ b/akka-actor/src/main/scala/akka/AkkaVersion.scala
@@ -0,0 +1,52 @@
+/**
+ * Copyright (C) 2009-2017 Lightbend Inc. <http://www.lightbend.com>
+ */
+package akka
+
+import akka.annotation.InternalApi
+
+import scala.annotation.varargs
+
+final class UnsupportedAkkaVersion private[akka] (msg: String) extends RuntimeException(msg)
+
+object AkkaVersion {
+  /**
+   * Check that the version of Akka is a specific patch version or higher and throw an [[UnsupportedAkkaVersion]]
+   * exception if the version requirement is not fulfilled.
+   *
+   * For example: `require("my-library", "2.5.4")` would fail if used with Akka 2.4.19 and 2.5.3, but succeed with 2.5.4
+   * and 2.6.1
+   *
+   * @param libraryName The name of the library or component requiring the Akka version, used in the error message.
+   * @param requiredVersion Minimal version that this library works with
+   */
+  def require(libraryName: String, requiredVersion: String): Unit = {
+    require(libraryName, requiredVersion, Version.current)
+  }
+
+  /**
+   * Internal API:
+   */
+  @InternalApi
+  private[akka] def require(libraryName: String, requiredVersion: String, currentVersion: String): Unit = {
+    val VersionPattern = """(\d+)\.(\d+)\.(\d+)(-(?:M|RC)\d+)?""".r
+    currentVersion match {
+      case VersionPattern(currentMajorStr, currentMinorStr, currentPatchStr, mOrRc) ⇒
+        requiredVersion match {
+          case requiredVersion @ VersionPattern(requiredMajorStr, requiredMinorStr, requiredPatchStr, _) ⇒
+            // a M or RC is basically inbetween versions, so offset
+            val currentPatch =
+              if (mOrRc ne null) currentPatchStr.toInt - 1
+              else currentPatchStr.toInt
+            if (requiredMajorStr.toInt != currentMajorStr.toInt ||
+              requiredMinorStr.toInt > currentMinorStr.toInt ||
+              (requiredMinorStr == currentMinorStr && requiredPatchStr.toInt > currentPatch))
+              throw new UnsupportedAkkaVersion(s"Current version of Akka is [$currentVersion], but $libraryName requires version [$requiredVersion]")
+          case _ ⇒ throw new IllegalArgumentException(s"Required version string is invalid: [$requiredVersion]")
+        }
+
+      case _ ⇒ // SNAPSHOT or unknown - you're on your own
+    }
+  }
+
+}