Merge pull request #752 from JeneaVranceanu/fix/abi-encoder-uint

fix: attempt to encode uint with a negative value results in a crash

Author: yaroslavyaroslav

Sources/Web3Core/EthereumABI/ABIEncoding.swift

@@ -218,19 +218,11 @@ public struct ABIEncoder {
     public static func encodeSingleType(type: ABI.Element.ParameterType, value: Any) -> Data? {
         switch type {
         case .uint:
-            if let biguint = convertToBigUInt(value) {
-                return biguint.abiEncode(bits: 256)
-            }
-            if let bigint = convertToBigInt(value) {
-                return bigint.abiEncode(bits: 256)
-            }
+            let biguint = convertToBigUInt(value)
+            return biguint == nil ? nil : biguint!.abiEncode(bits: 256)
         case .int:
-            if let biguint = convertToBigUInt(value) {
-                return biguint.abiEncode(bits: 256)
-            }
-            if let bigint = convertToBigInt(value) {
-                return bigint.abiEncode(bits: 256)
-            }
+            let bigint = convertToBigInt(value)
+            return bigint == nil ? nil : bigint!.abiEncode(bits: 256)
         case .address:
             if let string = value as? String {
                 guard let address = EthereumAddress(string) else {return nil}

Tests/web3swiftTests/localTests/ABIEncoderTest.swift

@@ -14,6 +14,16 @@ import BigInt
 
 class ABIEncoderTest: XCTestCase {
 
+    func testEncodeInt() {
+        XCTAssertEqual(ABIEncoder.encodeSingleType(type: .int(bits: 32), value: -10 as AnyObject)?.toHexString(), "fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff6")
+        XCTAssertEqual(ABIEncoder.encodeSingleType(type: .int(bits: 32), value: 10 as AnyObject)?.toHexString(), "000000000000000000000000000000000000000000000000000000000000000a")
+    }
+
+    func testEncodeUInt() {
+        XCTAssertEqual(ABIEncoder.encodeSingleType(type: .uint(bits: 32), value: -10 as AnyObject), nil)
+        XCTAssertEqual(ABIEncoder.encodeSingleType(type: .uint(bits: 32), value: 10 as AnyObject)?.toHexString(), "000000000000000000000000000000000000000000000000000000000000000a")
+    }
+
     func testSoliditySha3() throws {
         var hex = try ABIEncoder.soliditySha3(true).toHexString().addHexPrefix()
         assert(hex == "0x5fe7f977e71dba2ea1a68e21057beebb9be2ac30c6410aa38d4f3fbe41dcffd2")