More tests.

src/sbt-test/sbt-lock/staleHash/test

@@ -3,6 +3,8 @@
 # Precondition: jackson is inherited from transitiveProject.
 > reload
 > thisProject/checkExistsDependencyClasspath "com.fasterxml.jackson.core" "jackson-core" "2.2.2"
+> thisProject/assertSbtLockHashIsUpToDate
+> thisProject/assertSbtLockHashIsUpToDateInThisBuild
 
 # Update the jackson version in transitiveProject
 $ delete transitiveProject/build.sbt
@@ -12,3 +14,9 @@ $ copy-file transitiveProject/build.sbt.changed.txt transitiveProject/build.sbt
 > reload
 > thisProject/checkExistsDependencyClasspath "com.fasterxml.jackson.core" "jackson-core" "2.2.3"
 > thisProject/checkAbsentDependencyClasspath "com.fasterxml.jackson.core" "jackson-core" "2.2.2"
+
+# hash of thisProject has not changed:
+> thisProject/assertSbtLockHashIsUpToDate
+
+# but a hash of its dependency has changed:
+-> thisProject/assertSbtLockHashIsUpToDateInThisBuild

src/sbt-test/sbt-lock/staleHash/thisProject/build.sbt

@@ -22,3 +22,17 @@ InputKey[Unit]("checkAbsentDependencyClasspath") := {
     s"${module.mkString(":")} should not exist in dependencyClasspath: ${(dependencyClasspath in Compile).value}"
   )
 }
+
+TaskKey[Unit]("assertSbtLockHashIsUpToDate") := {
+  assert(
+    sbtLockHashIsUpToDate.value,
+    s"sbtLockHashIsUpToDate.value was not true"
+  )
+}
+
+TaskKey[Unit]("assertSbtLockHashIsUpToDateInThisBuild") := {
+  assert(
+    (sbtLockHashIsUpToDate in ThisBuild).value,
+    s"(sbtLockHashIsUpToDate in ThisBuild).value was not true"
+  )
+}