Merge pull request #14808 from dotty-staging/add-regression-tests

Add regression tests

Author: anatoliykmetyuk

tests/run-macros/simple-switch.check

@@ -0,0 +1,3 @@
+hello
+word
+bye

tests/run-macros/simple-switch/Macro_1.scala

@@ -0,0 +1,15 @@
+import scala.quoted.*
+
+inline def switch[T](n: Int)(inline xs: T*): T = ${ switchExpr('n, 'xs) }
+
+private def switchExpr[T: Type](n: Expr[Int], casesExpr: Expr[Seq[T]])(using Quotes): Expr[T] =
+  casesExpr match
+    case Varargs(caseExprs) => switchExpr(n, caseExprs)
+    case _ => quotes.reflect.report.errorAndAbort("switch does not support varargs unpacking")
+
+private def switchExpr[T: Type](n: Expr[Int], caseExprs: Seq[Expr[T]])(using Quotes): Expr[T] =
+  import quotes.reflect.*
+  val cases =
+    for (caseExpr, i) <- caseExprs.zipWithIndex
+    yield CaseDef(Literal(IntConstant(i)), None, caseExpr.asTerm)
+  Match(n.asTerm, cases.toList).asExprOf[T]

tests/run-macros/simple-switch/Main_2.scala

@@ -0,0 +1,11 @@
+@main def Test: Unit =
+  println(f(0))
+  println(f(1))
+  println(f(2))
+
+def f(i: Int): String =
+  switch(i)(
+    "hello",
+    "word",
+    "bye"
+  )

tests/run-macros/switch-match.check

@@ -0,0 +1 @@
+(4,ArraySeq(a, b))

tests/run-macros/switch-match/Macro_1.scala

@@ -0,0 +1,16 @@
+import scala.quoted.*
+
+inline def unswitch[T](inline x: T): (Int, Seq[T]) = ${ unswitchExpr('x) }
+
+private def unswitchExpr[T: Type](x: Expr[T])(using Quotes): Expr[(Int, Seq[T])] =
+  import quotes.reflect.*
+  x.asTerm match
+    case Inlined(_, _, Block(Nil, Match(scrut, cases))) =>
+      val exprs: List[Expr[T]] = cases.zipWithIndex.map {
+        case (CaseDef(Literal(IntConstant(i)), None, body), j) if i == j => body.asExprOf[T]
+        case (cse, _) => report.errorAndAbort("unexpected case: ", cse.pos)
+      }
+      scrut.asExpr match
+        case '{ $scrutExpr: Int } => '{ ($scrutExpr, ${Expr.ofSeq(exprs)}) }
+        case _ => report.errorAndAbort("not Int scrutinee", scrut.pos)
+    case _ => report.errorAndAbort("not a match", x)

tests/run-macros/switch-match/Main_2.scala

@@ -0,0 +1,9 @@
+@main def Test: Unit =
+  println(f(4))
+
+def f(x: Int): (Int, Seq[String]) =
+  unswitch {
+    x match
+      case 0 => "a"
+      case 1 => "b"
+  }