Add WireInit.apply that accepts DontCare (#731)

Prevents DontCare from affecting type inference
Fixes #728

1 files changed, 20 insertions, 0 deletions

diff --git a/src/test/scala/chiselTests/WireSpec.scala b/src/test/scala/chiselTests/WireSpec.scala
new file mode 100644
index 00000000..051880ee
--- /dev/null
+++ b/src/test/scala/chiselTests/WireSpec.scala
@@ -0,0 +1,20 @@
+// See LICENSE for license details.
+
+package chiselTests
+
+import chisel3._
+
+class WireSpec extends ChiselFlatSpec {
+  "WireInit.apply" should "work" in {
+    assertCompiles("WireInit(UInt(4.W), 2.U)")
+  }
+  it should "allow DontCare" in {
+    assertCompiles("WireInit(UInt(4.W), DontCare)")
+  }
+  it should "not allow DontCare to affect type inference" in {
+    assertCompiles("val x: UInt = WireInit(UInt(4.W), DontCare)")
+  }
+  it should "not allow init argument to affect type inference" in {
+    assertDoesNotCompile("val x: UInt = WireInit(UInt(4.W), 2.S)")
+  }
+}