Move treadle dependency to the tests (#1554)

Use inheritance to make TesterDriver Backend API extensible, then define
a TreadleBackend in the test project

1 files changed, 12 insertions, 0 deletions

diff --git a/src/test/scala/chisel3/testers/TestUtils.scala b/src/test/scala/chisel3/testers/TestUtils.scala
new file mode 100644
index 00000000..97cf9190
--- /dev/null
+++ b/src/test/scala/chisel3/testers/TestUtils.scala
@@ -0,0 +1,12 @@
+// See LICENSE for license details.
+
+package chisel3.testers
+
+import TesterDriver.Backend
+import firrtl.AnnotationSeq
+
+object TestUtils {
+  // Useful because TesterDriver.Backend is chisel3 package private
+  def containsBackend(annos: AnnotationSeq): Boolean =
+    annos.collectFirst { case b: Backend => b }.isDefined
+}