1 files changed, 72 insertions, 0 deletions
diff --git a/src/test/scala/chiselTests/AutoNestedCloneSpec.scala b/src/test/scala/chiselTests/AutoNestedCloneSpec.scala
new file mode 100644
index 00000000..178cb142
--- /dev/null
+++ b/src/test/scala/chiselTests/AutoNestedCloneSpec.scala
@@ -0,0 +1,72 @@
+// See LICENSE for license details.
+
+package chiselTests
+import Chisel.ChiselException
+import org.scalatest._
+import chisel3._
+
+class AutoNestedCloneSpec extends ChiselFlatSpec with Matchers {
+  behavior of "autoCloneType of inner Bundle in Chisel3"
+
+  it should "clone a doubly-nested inner bundle successfully" in {
+    elaborate { 
+      class Outer(val w: Int) extends Module {
+        class Middle(val w: Int) {
+          class InnerIOType extends Bundle {
+            val in = Input(UInt(w.W))
+          }
+          def getIO = new InnerIOType
+        }
+        val io = IO((new Middle(w)).getIO)
+      }
+      new Outer(2)
+    }
+  }
+
+  it should "clone an anonymous inner bundle successfully" in {
+    elaborate { 
+      class TestTop(val w: Int) extends Module {
+        val io = IO(new Bundle{ val a = UInt(w.W) })
+      }
+      new TestTop(2)
+    }
+  }
+
+  it should "pick the correct $outer instance for an anonymous inner bundle" in {
+    elaborate {
+      class Inner(val w: Int) extends Module {
+        val io = IO(new Bundle{
+          val in = Input(UInt(w.W))
+          val out = Output(UInt(w.W))
+        })
+      }
+      class Outer(val w: Int) extends Module {
+        val io = IO(new Bundle{
+          val in = Input(UInt(w.W))
+          val out = Output(UInt(w.W))
+        })
+        val i = Module(new Inner(w))
+        val iw = Wire(chiselTypeOf(i.io))
+        iw <> io
+        i.io <> iw
+      }
+      new Outer(2)
+    }
+  }
+
+  behavior of "anonymous doubly-nested inner bundle fails with clear error"
+  ( the[ChiselException] thrownBy {
+    elaborate {
+      class Outer(val w: Int) extends Module {
+        class Middle(val w: Int) {
+          def getIO = new Bundle {
+            val in = Input(UInt(w.W))
+          }
+        }
+        val io = IO((new Middle(w)).getIO)
+      }
+      new Outer(2)
+    }
+  }).getMessage should include("non-trivial inner Bundle class")
+
+}