[Neo Core Add] add char support (#3441)

* add char support

* Update src/Neo/VM/Helper.cs

* add char unit test

---------

Co-authored-by: Shargon <shargon@gmail.com>

Author: Jim8y

src/Neo/VM/Helper.cs

@@ -217,6 +217,9 @@ public static ScriptBuilder EmitPush(this ScriptBuilder builder, object obj)
                 case short data:
                     builder.EmitPush(data);
                     break;
+                case char data:
+                    builder.EmitPush((ushort)data);
+                    break;
                 case ushort data:
                     builder.EmitPush(data);
                     break;

tests/Neo.UnitTests/VM/UT_Helper.cs

@@ -18,6 +18,7 @@
 using Neo.SmartContract.Native;
 using Neo.VM;
 using Neo.VM.Types;
+using Org.BouncyCastle.Asn1.Tsp;
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -152,7 +153,7 @@ public void TestEmitAppCall3()
             sb.EmitDynamicCall(UInt160.Zero, "AAAAA", true);
             byte[] tempArray = new byte[38];
             tempArray[0] = (byte)OpCode.PUSHT;
-            tempArray[1] = (byte)OpCode.PUSH1;//arg.Length 
+            tempArray[1] = (byte)OpCode.PUSH1;//arg.Length
             tempArray[2] = (byte)OpCode.PACK;
             tempArray[3] = (byte)OpCode.PUSH15;//(byte)CallFlags.All;
             tempArray[4] = (byte)OpCode.PUSHDATA1;
@@ -401,6 +402,7 @@ public void TestEmitPush3()
             TestEmitPush3Byte();
             TestEmitPush3Short();
             TestEmitPush3Ushort();
+            TestEmitPush3Char();
             TestEmitPush3Int();
             TestEmitPush3Uint();
             TestEmitPush3Long();
@@ -472,6 +474,16 @@ private void TestEmitPush3Ushort()
             CollectionAssert.AreEqual(tempArray, sb.ToArray());
         }
 
+        private void TestEmitPush3Char()
+        {
+            ScriptBuilder sb = new ScriptBuilder();
+            char temp = char.MinValue;
+            VM.Helper.EmitPush(sb, temp);
+            byte[] tempArray = new byte[1];
+            tempArray[0] = (byte)OpCode.PUSH0;
+            CollectionAssert.AreEqual(tempArray, sb.ToArray());
+        }
+
         private void TestEmitPush3Short()
         {
             ScriptBuilder sb = new ScriptBuilder();
@@ -630,5 +642,28 @@ private void TestToParaMeter2VMArray()
             Assert.AreEqual(ContractParameterType.Array, parameter.Type);
             Assert.AreEqual(0, ((List<ContractParameter>)parameter.Value).Count);
         }
+
+        [TestMethod]
+        public void TestCharAsUInt16()
+        {
+            Assert.AreEqual(ushort.MaxValue, char.MaxValue);
+            Assert.AreEqual(ushort.MinValue, char.MinValue);
+
+            // test every char in a loop
+            for (int i = ushort.MinValue; i < char.MinValue; i++)
+            {
+                var c = Convert.ToChar(i);
+                Assert.AreEqual(i, c);
+            }
+
+            for (int i = ushort.MinValue; i < ushort.MaxValue; i++)
+            {
+                using var sbUInt16 = new ScriptBuilder();
+                using var sbChar = new ScriptBuilder();
+                sbUInt16.EmitPush((ushort)i);
+                sbChar.EmitPush(Convert.ToChar(i));
+                CollectionAssert.AreEqual(sbUInt16.ToArray(), sbChar.ToArray());
+            }
+        }
     }
 }