Add firrtl-json serializers (#1430)

* Add firrtl-json serializers

* Added support for ports, info. Added docs and tests

1 files changed, 42 insertions, 0 deletions

diff --git a/src/test/scala/firrtlTests/annotationTests/JsonProtocolSpec.scala b/src/test/scala/firrtlTests/annotationTests/JsonProtocolSpec.scala
new file mode 100644
index 00000000..2dce89db
--- /dev/null
+++ b/src/test/scala/firrtlTests/annotationTests/JsonProtocolSpec.scala
@@ -0,0 +1,42 @@
+// See LICENSE for license details.
+
+package firrtlTests.annotationTests
+
+import firrtl.Parser
+import firrtl.annotations.{Annotation, JsonProtocol, NoTargetAnnotation}
+import firrtl.ir._
+import org.scalatest.{FlatSpec, Matchers, PropSpec}
+
+case class AnAnnotation(
+    info: Info,
+    cir: Circuit,
+    mod: DefModule,
+    port: Port,
+    statement: Statement,
+    expr: Expression,
+    tpe: Type
+) extends NoTargetAnnotation
+
+class JsonProtocolSpec extends FlatSpec with Matchers {
+  "JsonProtocol" should "serialize and deserialize FIRRTL types" in {
+
+    val circuit =
+      """circuit Top: @[FPU.scala 509:25]
+        |  module Top:
+        |    input x: UInt
+        |    output y: UInt
+        |    y <= add(x, x)
+        |""".stripMargin
+    val cir = Parser.parse(circuit)
+    val mod = cir.modules.head
+    val port = mod.ports.head
+    val stmt = mod.asInstanceOf[Module].body
+    val expr = stmt.asInstanceOf[Block].stmts.head.asInstanceOf[Connect].expr
+    val tpe = port.tpe
+    val inputAnnos = Seq(AnAnnotation(cir.info, cir, mod, port, stmt, expr, tpe))
+    val annosString = JsonProtocol.serialize(inputAnnos)
+    val outputAnnos = JsonProtocol.deserialize(annosString)
+    inputAnnos should be (outputAnnos)
+  }
+
+}