Use skipTests instead of includeTests

COMPILING.md

@@ -21,10 +21,10 @@ Setting up the test suite for Millfork is tricky, so if you don't need the tests
 
 #### Steps
 
-* run `sbt compile`  
+* run `sbt -DskipTests compile`  
 to compile the project
 
-* run `sbt assembly`  
+* run `sbt -DskipTests assembly`  
 to build the executable jar file, it should appear in `target/scala-2.12`
 
 ### Building with tests
@@ -55,9 +55,9 @@ Test suite is useful if you plan on modifying the compiler. Some test dependenci
 
 * navigate to the project directory 
 
-* run `sbt -DincludeTests compile` to compile the project
+* run `sbt compile` to compile the project
 
-* run `sbt -DincludeTests assemble` to build the executable jar file, it should appear in `target/scala-2.12`
+* run `sbt assemble` to build the executable jar file, it should appear in `target/scala-2.12`
 
 ### Building a native executable
 

build.sbt

@@ -31,22 +31,23 @@ val testDependencies = Seq(
   "org.graalvm.js" % "js-scriptengine" % "20.2.0" % "test"
 )
 
-val includesTests = System.getProperty("includeTests") != null
+val includesTests = System.getProperty("skipTests") == null
 
 libraryDependencies ++=(
   if (includesTests) {
     println("Including test dependencies")
     testDependencies
   } else {
-    Seq()
+    Seq[ModuleID]()
   }
 )
 
 (if (!includesTests) {
   // Disable assembling tests
-  test in assembly := {}
-  // SBT doesn't like returning Unit, so return Seq
-} else Seq())
+  sbt.internals.DslEntry.fromSettingsDef(test in assembly := {})
+} else {
+  sbt.internals.DslEntry.fromSettingsDef(Seq[sbt.Def.Setting[_]]())
+})
 
 mainClass in Compile := Some("millfork.Main")