add test for personal signing and EC recover. Manually tested in JavaScript using ethereumjs-utils

Author: Alex Vlasov

web3swiftTests/web3swiftTests.swift

@@ -1991,6 +1991,26 @@ class web3swiftTests: XCTestCase {
         }
     }
 
+    func testPersonalSignature() {
+        let web3 = Web3.InfuraRinkebyWeb3()
+        let tempKeystore = try! EthereumKeystoreV3(password: "")
+        let keystoreManager = KeystoreManager([tempKeystore!])
+        web3.addKeystoreManager(keystoreManager)
+        let message = "Hello World"
+        let expectedAddress = keystoreManager.addresses![0]
+        print(expectedAddress)
+        let signRes = web3.personal.signPersonalMessage(message: message.data(using: .utf8)!, from: expectedAddress, password: "")
+        guard case .success(let signature) = signRes else {return XCTFail()}
+        let unmarshalledSignature = SECP256K1.unmarshalSignature(signatureData: signature)!
+        print("V = " + String(unmarshalledSignature.v))
+        print("R = " + Data(unmarshalledSignature.r).toHexString())
+        print("S = " + Data(unmarshalledSignature.s).toHexString())
+        print("Personal hash = " + Web3.Utils.hashPersonalMessage(message.data(using: .utf8)!)!.toHexString())
+        let recoveredSigner = web3.personal.ecrecover(personalMessage: message.data(using: .utf8)!, signature: signature)
+        guard case .success(let signer) = recoveredSigner else {return XCTFail()}
+        XCTAssert(expectedAddress == signer, "Failed to sign personal message")
+    }
+    
     func testPerformanceExample() {
         // This is an example of a performance test case.
         self.measure {