fix(sc): fix incorrect emitting of numbers in ScriptBuilder (#913)

CityOfZion · Aug 30, 2023 · 7ddb0e6 · 7ddb0e6
1 parent b419005
commit 7ddb0e6
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diff --git a/docs/changelog/v5.md b/docs/changelog/v5.md
@@ -7,6 +7,7 @@ sidebar_position: 1
 
 # 5.5.1
 - sc
+  - Fix incorrect emitting of numbers in `ScriptBuilder`.
   - Add support for `Map` type in `emitContractParam` function.
 
 # 5.5.0

diff --git a/packages/neon-core/__tests__/sc/ScriptBuilder.ts b/packages/neon-core/__tests__/sc/ScriptBuilder.ts
@@ -191,6 +191,13 @@ describe("emitNumber", () => {
     ["long min", "-9223372036854775808", "030000000000000080"],
     ["long max", "9223372036854775807", "03ffffffffffffff7f"],
     ["ulong max", "18446744073709551615", "04ffffffffffffffff0000000000000000"],
+    ["pushint8", 0x1f, "001f"],
+    ["pushint16", 0xff, "01ff00"],
+    ["pushin32", 0xffff, "02ffff0000"],
+    ["pushint64", 0xffffffff, "03ffffffff00000000"],
+    ["issue #911 #1", -129, "017fff"],
+    ["issue #911 #2", -150, "016aff"],
+    ["issue #911 #3", -255, "0101ff"],
   ])("%s", (_msg: string, data: number | string, expected: string) => {
     const result = new ScriptBuilder().emitNumber(data).build();
     expect(result).toBe(expected);

diff --git a/packages/neon-core/src/sc/ScriptBuilder.ts b/packages/neon-core/src/sc/ScriptBuilder.ts
@@ -1,6 +1,6 @@
 import BN from "bn.js";
 import {
-  ab2hexstring,
+  BigInteger,
   HexString,
   int2hex,
   num2hexstring,
@@ -229,20 +229,17 @@ export class ScriptBuilder extends StringStream {
       return this.emit(OpCode.PUSH0 + bn.toNumber());
     }
     const negative = bn.isNeg();
-    const msbSet = bn.testn(bn.byteLength() * 8 - 1);
-    const occupiedBytes = bn.byteLength();
-    const targetBytes = this.roundToBestIntSize(
-      !negative && msbSet ? occupiedBytes + 1 : occupiedBytes
-    );
+    const bigint = BigInteger.fromNumber(num);
+    const occupiedBytes = bigint.toReverseTwos().length / 2;
+    const targetBytes = this.roundToBestIntSize(occupiedBytes);
 
     // Catch case 64
     if (targetBytes > 32) {
       throw new Error(`Number too long to be emitted: ${num.toString()}`);
     }
 
-    const hex = ab2hexstring(
-      bn.toTwos(bn.byteLength() * 8).toArray("le", targetBytes)
-    );
+    let hex = bigint.toReverseTwos();
+    hex = this.padRight(hex, targetBytes, negative);
 
     switch (targetBytes) {
       case 1:
@@ -282,6 +279,19 @@ export class ScriptBuilder extends StringStream {
     }
   }
 
+  private padRight(
+    data: string,
+    targetLength: number,
+    isSigned: boolean
+  ): string {
+    if (data.length / 2 >= targetLength) return data;
+    const pad = isSigned ? "ff" : "00";
+    while (data.length / 2 != targetLength) {
+      data = data + pad;
+    }
+    return data;
+  }
+
   /**
    * Private method to append a ContractParam
    */