tree-template: implemented fromHex, templateHex

interpreter/shared/src/main/scala/sigmastate/Values.scala

@@ -15,15 +15,17 @@ import sigmastate.serialization.OpCodes._
 import sigmastate.TrivialProp.{FalseProp, TrueProp}
 import sigmastate.Values.ErgoTree.substConstants
 import sigmastate.basics.DLogProtocol.ProveDlog
-import sigmastate.basics.{ProveDHTuple, CryptoConstants}
+import sigmastate.basics.{CryptoConstants, ProveDHTuple}
 import sigmastate.lang.Terms._
 import sigmastate.utxo._
 import sigmastate.eval._
 import sigmastate.eval.Extensions._
 import scalan.util.Extensions.ByteOps
 import sigmastate.interpreter.ErgoTreeEvaluator._
 import debox.cfor
+import scorex.util.encode.Base16
 import sigmastate.exceptions.InterpreterException
+
 import scala.language.implicitConversions
 import scala.reflect.ClassTag
 import sigmastate.lang.CheckingSigmaBuilder._
@@ -1314,13 +1316,16 @@ object Values {
     }
 
     /** Serialized proposition expression of SigmaProp type with
-      * ConstantPlaceholder nodes instead of Constant nodes 
+      * ConstantPlaceholder nodes not replaced by Constant nodes.
       */
     lazy val template: Array[Byte] = {
       val r = SigmaSerializer.startReader(bytes)
       DefaultSerializer.deserializeHeaderWithTreeBytes(r)._4
     }
 
+    /** Base16 encoding of `template` bytes. */
+    def templateHex: String = Base16.encode(template)
+
     /** Get proposition expression from this contract.
       * When root.isRight then
       *   if replaceConstants == false this is the same as `root.right.get`.
@@ -1496,6 +1501,24 @@ object Values {
       */
     def withSegregation(prop: SigmaPropValue): ErgoTree =
       withSegregation(DefaultHeader, prop)
+
+    /** Deserializes an ErgoTree instance from a hexadecimal string.
+      *
+      * @param hex a hexadecimal string representing the serialized ErgoTree
+      */
+    def fromHex(hex: String): ErgoTree = {
+      val bytes = Base16.decode(hex).get
+      fromBytes(bytes)
+    }
+
+    /** Deserializes an ErgoTree instance from an array of bytes.
+      *
+      * @param bytes an array of bytes representing the serialized ErgoTree
+      */
+    def fromBytes(bytes: Array[Byte]): ErgoTree = {
+      ErgoTreeSerializer.DefaultSerializer.deserializeErgoTree(bytes)
+    }
+
   }
 
 }

sc/shared/src/test/scala/sigmastate/ErgoTreeSpecification.scala

@@ -75,12 +75,19 @@ class ErgoTreeSpecification extends SigmaDslTesting with ContractsTestkit {
   }
 
   property("ErgoTree.template") {
-    val t = new ErgoTree(
-      16.toByte,
-      Array(IntConstant(1)),
-      Right(BoolToSigmaProp(EQ(ConstantPlaceholder(0, SInt), IntConstant(1))))
-    )
-    t.template shouldBe ErgoAlgos.decodeUnsafe("d19373000402")
+    {
+      val t = new ErgoTree(
+        16.toByte,
+        Array(IntConstant(1)),
+        Right(BoolToSigmaProp(EQ(ConstantPlaceholder(0, SInt), IntConstant(1))))
+      )
+      t.template shouldBe ErgoAlgos.decodeUnsafe("d19373000402")
+    }
+
+    {
+      val t = ErgoTree.fromHex("100604000e000400040005000500d803d601e30004d602e4c6a70408d603e4c6a7050595e67201d804d604b2a5e4720100d605b2db63087204730000d606db6308a7d60799c1a7c17204d1968302019683050193c27204c2a7938c720501730193e4c672040408720293e4c672040505720393e4c67204060ec5a796830201929c998c7205029591b1720673028cb272067303000273047203720792720773057202")
+       t.templateHex shouldBe "d803d601e30004d602e4c6a70408d603e4c6a7050595e67201d804d604b2a5e4720100d605b2db63087204730000d606db6308a7d60799c1a7c17204d1968302019683050193c27204c2a7938c720501730193e4c672040408720293e4c672040505720393e4c67204060ec5a796830201929c998c7205029591b1720673028cb272067303000273047203720792720773057202"
+    }
   }
 
   property("ErgoTree.bytes") {

sdk/js/src/main/scala/org/ergoplatform/sdk/js/ErgoTree.scala

@@ -26,6 +26,14 @@ class ErgoTree(tree: Values.ErgoTree) extends js.Object {
   /** Serializes the ErgoTree instance to a hexadecimal string. */
   def toHex(): String = tree.bytesHex
 
+  /** Serialized proposition expression of SigmaProp type with
+    * ConstantPlaceholder nodes not replaced by Constant nodes.
+    */
+  def template(): Array[Byte] = tree.template
+
+  /** Base16 encoding of `template` bytes. */
+  def templateHex(): String = tree.templateHex
+
   /** Returns segregated constants of this tree as [[js.Array]]. */
   def constants(): js.Array[Value] = {
     val constants = tree.constants
@@ -42,17 +50,14 @@ object ErgoTree extends js.Object {
     *
     * @param hex a hexadecimal string representing the serialized ErgoTree
     */
-  def fromHex(hex: String): ErgoTree = {
-    val bytes = Base16.decode(hex).get
-    fromBytes(bytes)
-  }
+  def fromHex(hex: String): ErgoTree =
+    new ErgoTree(Values.ErgoTree.fromHex(hex))
 
   /** Deserializes an ErgoTree instance from an array of bytes.
     *
     * @param bytes an array of bytes representing the serialized ErgoTree
     */
   def fromBytes(bytes: Array[Byte]): ErgoTree = {
-    val tree = ErgoTreeSerializer.DefaultSerializer.deserializeErgoTree(bytes)
-    new ErgoTree(tree)
+    new ErgoTree(Values.ErgoTree.fromBytes(bytes))
   }
 }

sigma-js/tests/js/ErgoTree.spec.js

@@ -29,5 +29,11 @@ describe("Smoke tests for ErgoTree", () => {
     let constants = tree.constants().map(c => c.toHex())
     expect(constants).toEqual(["0400", "0e00", "0400", "0400", "0500", "0500"])
   });
+
+  it("Has template", () => {
+    let tree = ErgoTreeObj.fromHex(hex);
+    let templateHex = tree.templateHex();
+    expect(templateHex).toEqual("d803d601e30004d602e4c6a70408d603e4c6a7050595e67201d804d604b2a5e4720100d605b2db63087204730000d606db6308a7d60799c1a7c17204d1968302019683050193c27204c2a7938c720501730193e4c672040408720293e4c672040505720393e4c67204060ec5a796830201929c998c7205029591b1720673028cb272067303000273047203720792720773057202")
+  });
 });