package scala.lang.primitives
import org.junit.Test
import org.junit.Assert._
import org.junit.runner.RunWith
import org.junit.runners.JUnit4
import scala.tools.testing.AssertUtil._
import scala.tools.testing.RunTesting
object BoxUnboxTest {
class VCI(val x: Int) extends AnyVal { override def toString = "" + x }
}
@RunWith(classOf[JUnit4])
class BoxUnboxTest extends RunTesting {
import runner._
def genericNull[T] = null.asInstanceOf[T] // allowed, see SI-4437, point 2
@Test
def boxUnboxInt(): Unit = {
val b = new Integer(1)
val u = 1
assertEquals(1.toInt, u)
assertEquals(Predef.int2Integer(1), b)
assertEquals(1: Integer, b)
assertEquals(Int.box(1), b)
assertEquals(1.asInstanceOf[Object], b)
assertThrows[ClassCastException]("".asInstanceOf[Integer])
assertEquals(Predef.Integer2int(b), u)
assertEquals(b: Int, u)
assertEquals(Int.unbox(b), u)
assertEquals(b.asInstanceOf[Int], u)
assertEquals(b.intValue, u)
assertEquals(b.toInt, u)
intWrapper(b).toInt
assertThrows[ClassCastException](Int.unbox(""))
assertThrows[ClassCastException]("".asInstanceOf[Int])
// null unboxing in various positions
val n1 = Int.unbox(null)
assertEquals(n1, 0)
val n2 = Predef.Integer2int(null)
assertEquals(n2, 0)
val n3 = (null: Integer): Int
assertEquals(n3, 0)
val n4 = null.asInstanceOf[Int]
assertEquals(n4, 0)
val n5 = null.asInstanceOf[Int] == 0
assertTrue(n5)
val n6 = null.asInstanceOf[Int] == null
assertFalse(n6)
val n7 = null.asInstanceOf[Int] != 0
assertFalse(n7)
val n8 = null.asInstanceOf[Int] != null
assertTrue(n8)
val mp = new java.util.HashMap[Int, Int]
val n9 = mp.get(0)
assertEquals(n9, 0)
val n10 = mp.get(0) == null // SI-602
assertThrows[AssertionError](assertFalse(n10)) // should not throw
def f(a: Any) = "" + a
val n11 = f(null.asInstanceOf[Int])
assertEquals(n11, "0")
def n12 = genericNull[Int]
assertEquals(n12, 0)
}
@Test
def numericConversions(): Unit = {
val i1 = 1L.asInstanceOf[Int]
assertEquals(i1, 1)
assertThrows[ClassCastException] {
val i2 = (1L: Any).asInstanceOf[Int] // SI-1448, should not throw. see also SI-4437 point 1.
assertEquals(i2, 1)
}
}
@Test
def boxUnboxBoolean(): Unit = {
val n1 = Option(null.asInstanceOf[Boolean])
assertEquals(n1, Some(false))
}
@Test
def boxUnboxUnit(): Unit = {
// should not use assertEquals in this test: it takes two Object parameters. normally, Unit does
// not conform to Object, but for Java-defined methods scalac makes an exception and treats them
// as Any. passing a Unit as Any makes the compiler go through another layer of boxing, so it
// can hide some bugs (where we actually have a null, but the compiler makes it a ()).
var v = 0
def eff() = { v = 1 }
def chk() = { assert(v == 1); v = 0 }
val b = runtime.BoxedUnit.UNIT
assert(eff() == b); chk()
assert(Unit.box(eff()) == b); chk()
assert(().asInstanceOf[Object] == b)
Unit.unbox({eff(); b}); chk()
Unit.unbox({eff(); null}); chk()
assertThrows[ClassCastException](Unit.unbox({eff(); ""})); chk()
val n1 = null.asInstanceOf[Unit]
assert(n1 == b)
val n2 = null.asInstanceOf[Unit] == b
assert(n2)
def f(a: Any) = "" + a
val n3 = f(null.asInstanceOf[Unit])
assertEquals(n3, "()")
}
@Test
def t9671(): Unit = {
val code =
"""import scala.lang.primitives.BoxUnboxTest.VCI
|
|def f1(a: Any) = "" + a
|def f2(a: AnyVal) = "" + a
|def f3[T](a: T) = "" + a
|def f4(a: Int) = "" + a
|def f5(a: VCI) = "" + a
|def f6(u: Unit) = "" + u
|
|def n1: AnyRef = null
|def n2: Null = null
|def n3: Any = null
|def n4[T]: T = null.asInstanceOf[T]
|
|def npe(s: => String) = try { s; throw new Error() } catch { case _: NullPointerException => "npe" }
|
| f1(null.asInstanceOf[Int]) +
| f1( n1.asInstanceOf[Int]) +
| f1( n2.asInstanceOf[Int]) +
| f1( n3.asInstanceOf[Int]) +
| f1( n4[Int]) + // "null"
|"-" +
| f1(null.asInstanceOf[VCI]) +
|npe(f1( n1.asInstanceOf[VCI])) + // SI-8097
| f1( n2.asInstanceOf[VCI]) +
|npe(f1( n3.asInstanceOf[VCI])) + // SI-8097
| f1( n4[VCI]) + // "null"
|"-" +
| f1(null.asInstanceOf[Unit]) +
| f1( n1.asInstanceOf[Unit]) +
| f1( n2.asInstanceOf[Unit]) +
| f1( n3.asInstanceOf[Unit]) +
| f1( n4[Unit]) + // "null"
|"-" +
| f2(null.asInstanceOf[Int]) +
| f2( n1.asInstanceOf[Int]) +
| f2( n2.asInstanceOf[Int]) +
| f2( n3.asInstanceOf[Int]) +
| f2( n4[Int]) + // "null"
|"-" +
| f2(null.asInstanceOf[VCI]) +
|npe(f2( n1.asInstanceOf[VCI])) + // SI-8097
| f2( n2.asInstanceOf[VCI]) +
|npe(f2( n3.asInstanceOf[VCI])) + // SI-8097
| f2( n4[VCI]) + // "null"
|"-" +
| f2(null.asInstanceOf[Unit]) +
| f2( n1.asInstanceOf[Unit]) +
| f2( n2.asInstanceOf[Unit]) +
| f2( n3.asInstanceOf[Unit]) +
| f2( n4[Unit]) + // "null"
|"-" +
| f3(null.asInstanceOf[Int]) +
| f3( n1.asInstanceOf[Int]) +
| f3( n2.asInstanceOf[Int]) +
| f3( n3.asInstanceOf[Int]) +
| f3( n4[Int]) + // "null"
|"-" +
| f3(null.asInstanceOf[VCI]) +
|npe(f3( n1.asInstanceOf[VCI])) + // SI-8097
| f3( n2.asInstanceOf[VCI]) +
|npe(f3( n3.asInstanceOf[VCI])) + // SI-8097
| f3( n4[VCI]) + // "null"
|"-" +
| f3(null.asInstanceOf[Unit]) +
| f3( n1.asInstanceOf[Unit]) +
| f3( n2.asInstanceOf[Unit]) +
| f3( n3.asInstanceOf[Unit]) +
| f3( n4[Unit]) + // "null"
|"-" +
| f4(null.asInstanceOf[Int]) +
| f4( n1.asInstanceOf[Int]) +
| f4( n2.asInstanceOf[Int]) +
| f4( n3.asInstanceOf[Int]) +
| f4( n4[Int]) +
|"-" +
| f5(null.asInstanceOf[VCI]) +
|npe(f5( n1.asInstanceOf[VCI])) + // SI-8097
| f5( n2.asInstanceOf[VCI]) +
|npe(f5( n3.asInstanceOf[VCI])) + // SI-8097
|npe(f5( n4[VCI])) + // SI-8097
|"-" +
| f6(null.asInstanceOf[Unit]) +
| f6( n1.asInstanceOf[Unit]) +
| f6( n2.asInstanceOf[Unit]) +
| f6( n3.asInstanceOf[Unit]) +
| f6( n4[Unit]) // "null"
""".stripMargin
assertEquals(run[String](code),
"0000null-0npe0npenull-()()()()null-0000null-0npe0npenull-()()()()null-0000null-0npe0npenull-()()()()null-00000-0npe0npenpe-()()()()null")
}
}
