diff --git a/tests/pos-special/fatal-warnings/i10994.scala b/tests/pos-special/fatal-warnings/i10994.scala
new file mode 100644
index 000000000000..99ae647466b1
--- /dev/null
+++ b/tests/pos-special/fatal-warnings/i10994.scala
@@ -0,0 +1,2 @@
+def foo = true match
+  case (b: Boolean): Boolean => ()
diff --git a/tests/pos-special/fatal-warnings/i11729.scala b/tests/pos-special/fatal-warnings/i11729.scala
new file mode 100644
index 000000000000..7ba41d081e3b
--- /dev/null
+++ b/tests/pos-special/fatal-warnings/i11729.scala
@@ -0,0 +1,26 @@
+type Return[X] = X match
+    case List[t] => List[t]
+    case Any => List[X]
+
+object Return:
+  def apply[A](a:A):Return[A] = a match 
+    case a: List[t] => a
+    case a: Any => List(a)
+
+object Test1:
+  Return(1).map(x => x)
+
+
+type Boxed[X] = X match
+   case Box[t] => Box[t]
+   case Any => Box[X]
+
+def box[X](x: X): Boxed[X] = x match
+   case b: Box[t] => b
+   case x: Any => Box(x)
+
+case class Box[A](a:A):
+  def map[B](f: A => B): Box[B] = Box(f(a))
+
+object Test2:
+   box(box(1)).map(_ + 1)
diff --git a/tests/pos/i10389.scala b/tests/pos/i10389.scala
new file mode 100644
index 000000000000..a23f0d269a21
--- /dev/null
+++ b/tests/pos/i10389.scala
@@ -0,0 +1,9 @@
+import scala.util._
+
+object FooBar {
+  def foo = List("1","two","3").collect{ x => 
+    Try(x.toInt) match { 
+      case Success(int) => int 
+    }
+  }
+}
diff --git a/tests/pos/i10897.scala b/tests/pos/i10897.scala
new file mode 100644
index 000000000000..da583090992b
--- /dev/null
+++ b/tests/pos/i10897.scala
@@ -0,0 +1,6 @@
+import Tuple.Union
+
+object Foo
+
+val x = summon[Union[(Foo.type, 1)] =:= (Foo.type | 1)] // doesn't compile
+val y = summon[Union[(Foo.type, 1, String)] =:= (Foo.type | 1 | String)] // compiles
diff --git a/tests/pos/i11163.scala b/tests/pos/i11163.scala
new file mode 100644
index 000000000000..acf5629d1ae9
--- /dev/null
+++ b/tests/pos/i11163.scala
@@ -0,0 +1,12 @@
+inline def summonA[T](using x: T): x.type = x
+inline def summonB[T](using inline x: T): x.type = x
+inline def summonC[T](using inline x: T): T = x
+
+trait Foo:
+  def f: Int = 9
+
+def test(using Foo) =
+  summonA[Foo].f
+  summonB[Foo].f
+  summonC[Foo].f
+  ()
diff --git a/tests/pos/i11556.scala b/tests/pos/i11556.scala
new file mode 100644
index 000000000000..881fc6d0fc10
--- /dev/null
+++ b/tests/pos/i11556.scala
@@ -0,0 +1,24 @@
+type Traverser[-I, +O] = I => LazyList[(O)]
+extension[I, O](ta: Traverser[I, O])
+    def ~>[P](tb: Traverser[O, P]): Traverser[I, P] = ???
+
+class Graph { class Node }
+
+case class Path[+E](e: E)
+type Query[-I, +O] = Traverser[Path[I], Path[O]]
+
+def nodesQ(using g: Graph): Query[Nothing, g.Node] = ???
+def outsQ(using g: Graph): Query[g.Node, g.Node] = ???
+
+object graph extends Graph
+import graph._
+given graph.type = graph
+
+object Issue11556:
+  val q1: Query[Nothing, Node] = nodesQ ~> outsQ
+  implicitly[q1.type <:< Query[Nothing, Node]]
+
+  val q2 = nodesQ ~> outsQ
+  val q3: Query[Nothing, Node] = q2
+  implicitly[q2.type <:< Query[Nothing, Node]]
+end Issue11556
diff --git a/tests/pos/i12474.scala b/tests/pos/i12474.scala
new file mode 100644
index 000000000000..41762fba55c1
--- /dev/null
+++ b/tests/pos/i12474.scala
@@ -0,0 +1,17 @@
+package bugreport
+
+import scala.compiletime.erasedValue
+
+trait Show[A]:
+  def show(a: A): String
+
+inline def showTuple[Types]: Show[Types] =
+  inline erasedValue[Types] match
+    case _: (head *: tail) =>
+      val instance =
+        new Show[head *: tail]:
+          def show(tuple: head *: tail): String = "dummy"
+      instance.asInstanceOf[Show[Types]]
+
+@main def run() =
+  showTuple[(Int, Int)]
diff --git a/tests/pos/i9769.scala b/tests/pos/i9769.scala
new file mode 100644
index 000000000000..1c57b4bb94d3
--- /dev/null
+++ b/tests/pos/i9769.scala
@@ -0,0 +1,9 @@
+object Main {
+  val lifeOfPi = 3.14159
+  val fInterpolator = f"The approximate value of pi is $lifeOfPi%4.2f"
+  
+  def main(args: Array[String]): Unit = {
+    println(fInterpolator)
+  }
+
+}
diff --git a/tests/pos/i9833.scala b/tests/pos/i9833.scala
new file mode 100644
index 000000000000..4e5594707831
--- /dev/null
+++ b/tests/pos/i9833.scala
@@ -0,0 +1,7 @@
+object Main extends App:
+  enum Extends[A, B]:
+    case Ev[B, A <: B]() extends (A Extends B)
+
+    def cast(a: A): B = this match {
+      case Extends.Ev() => a
+    }