Add cache tests

This adds scripted test for cached compilation and tests.

sbt-app/src/sbt-test/cache/cached-compile/Main.scala

@@ -0,0 +1,2 @@
+@main def main(args: String*) =
+  assert(args(0).toInt == A.x )

sbt-app/src/sbt-test/cache/cached-compile/build.sbt

@@ -0,0 +1,16 @@
+import sbt.internal.util.CacheEventSummary
+
+lazy val checkMiss = taskKey[Unit]("")
+
+Global / localCacheDirectory := baseDirectory.value / "diskcache"
+
+scalaVersion := "3.6.4"
+checkMiss := {
+  val s = streams.value
+  val config = Def.cacheConfiguration.value
+  val prev = config.cacheEventLog.previous match
+    case s: CacheEventSummary.Data => s
+    case _                         => sys.error(s"empty event log")
+  s.log.info(prev.missCount.toString) 
+  assert(prev.missCount == 2, s"prev.missCount = ${prev.missCount}")
+}

sbt-app/src/sbt-test/cache/cached-compile/changes/A1.scala

@@ -0,0 +1 @@
+object A { final val x = 1 }

sbt-app/src/sbt-test/cache/cached-compile/changes/A2.scala

@@ -0,0 +1 @@
+object A { final val x = 2 }

sbt-app/src/sbt-test/cache/cached-compile/test

@@ -0,0 +1,7 @@
+$ copy-file changes/A1.scala A.scala
+> run 1
+> checkMiss
+
+$ copy-file changes/A2.scala A.scala
+> run 2
+> checkMiss

sbt-app/src/sbt-test/cache/cached-test/build.sbt

@@ -0,0 +1,19 @@
+import sbt.internal.util.CacheEventSummary
+
+lazy val checkHit = taskKey[Unit]("")
+lazy val verify = "com.eed3si9n.verify" %% "verify" % "1.0.0"
+
+Global / localCacheDirectory := baseDirectory.value / "diskcache"
+
+scalaVersion := "3.6.4"
+libraryDependencies += verify % Test
+testFrameworks += new TestFramework("verify.runner.Framework")
+
+checkHit := {
+  val s = streams.value
+  val config = Def.cacheConfiguration.value
+  val prev = config.cacheEventLog.previous match
+    case s: CacheEventSummary.Data => s
+    case _                         => sys.error(s"empty event log")
+  assert(prev.missCount == 0, s"prev.missCount = ${prev.missCount}")
+}

sbt-app/src/sbt-test/cache/cached-test/changed/MathFunction.scala

@@ -0,0 +1,5 @@
+package example
+
+object MathFunction:
+  def times2(i: Int): Int = 2 * 2
+end MathFunction

sbt-app/src/sbt-test/cache/cached-test/src/main/scala/MathFunction.scala

@@ -0,0 +1,5 @@
+package example
+
+object MathFunction:
+  def times2(i: Int): Int = i * 2
+end MathFunction

sbt-app/src/sbt-test/cache/cached-test/src/test/scala/MathFunctionTest.scala

@@ -0,0 +1,6 @@
+package example
+
+object MathFunctionTest extends verify.BasicTestSuite:
+  test("times2 should double the input"):
+    assert(MathFunction.times2(4) == 8)
+end MathFunctionTest

sbt-app/src/sbt-test/cache/cached-test/test

@@ -0,0 +1,7 @@
+> test
+
+> test
+> checkHit
+
+$ copy-file changed/MathFunction.scala src/test/scala/MathFunction.scala
+-> test