FA1.2 token contract operations

Tests/IntegrationTests/Dexter/TokenContractIntegrationTests.swift

@@ -63,6 +63,28 @@ class TokenContractClientIntegrationTests: XCTestCase {
     wait(for: [ completionExpectation ], timeout: .expectationTimeout)
   }
 
+  public func testApproveAllowanceTokens() {
+    let completionExpectation = XCTestExpectation(description: "Completion called")
+
+    tokenContractClient.approveAllowance(
+      source: Wallet.tokenOwner.address,
+      spender: Address.tokenRecipient,
+      allowance: 1,
+      signatureProvider: Wallet.tokenOwner
+    ) { result in
+      switch result {
+      case .success(let hash):
+        print(hash)
+        completionExpectation.fulfill()
+      case .failure(let error):
+        print(error)
+        XCTFail()
+      }
+    }
+
+    wait(for: [ completionExpectation ], timeout: .expectationTimeout)
+  }
+
   public func testGetBalance() {
     let completionExpectation = XCTestExpectation(description: "Completion called")
 

TezosKit/Common/Services/NetworkClient.swift

@@ -94,7 +94,6 @@ public class NetworkClientImpl: NetworkClient {
       let payload = rpc.payload,
       let payloadData = payload.data(using: .utf8)
     {
-      print("payload: \(payload)")
       urlRequest.httpMethod = "POST"
       urlRequest.cachePolicy = .reloadIgnoringCacheData
       urlRequest.httpBody = payloadData
@@ -116,10 +115,6 @@ public class NetworkClientImpl: NetworkClient {
         return
       }
 
-      print("Data: \(String(data: data!, encoding: .utf8))")
-      print("Error: \(error)")
-      print("----------------------------------------")
-
       let result = self.responseHandler.handleResponse(
         response: response,
         data: data,

TezosKit/Dexter/TokenContractClient.swift

@@ -1,9 +1,14 @@
 // Copyright Keefer Taylor, 2019.
 
-/// A client for a token contract.
+/// A client for an  FA1.2 Token Contract.
 ///
-/// - See: https://gitlab.com/camlcase-dev/dexter
+/// - See: https://gitlab.com/tzip/tzip/tree/master/proposals/tzip-7
 public class TokenContractClient {
+  private enum EntryPoint {
+    public static let approve = "approve"
+    public static let transfer = "transfer"
+  }
+
   private enum JSON {
     public enum Keys {
       public static let args = "args"
@@ -49,7 +54,6 @@ public class TokenContractClient {
     completion: @escaping (Result<String, TezosKitError>) -> Void
   ) {
     let amount = Tez.zeroBalance
-    let entrypoint = "transfer"
     let parameter = PairMichelsonParameter(
       left: PairMichelsonParameter(
         left: StringMichelsonParameter(string: source),
@@ -61,7 +65,40 @@ public class TokenContractClient {
     tezosNodeClient.call(
       contract: tokenContractAddress,
       amount: amount,
-      entrypoint: entrypoint,
+      entrypoint: EntryPoint.transfer,
+      parameter: parameter,
+      source: source,
+      signatureProvider: signatureProvider,
+      operationFeePolicy: .estimate,
+      completion: completion
+    )
+  }
+
+  /// Approve an allowance.
+  ///
+  /// - Parameters:
+  ///   - source: The address initiating the approval.
+  ///   - spender: The address being approved.
+  ///   - allowance: The number of tokens to approve.
+  ///   - signatureProvider: An opaque object that can sign the transaction.
+  ///   - completion: A completion block called with the operation hash or an error.
+  public func approveAllowance(
+    source: Address,
+    spender: Address,
+    allowance: Int,
+    signatureProvider: SignatureProvider,
+    completion: @escaping (Result<String, TezosKitError>) -> Void
+  ) {
+    let amount = Tez.zeroBalance
+    let parameter = PairMichelsonParameter(
+      left: StringMichelsonParameter(string: spender),
+      right: IntMichelsonParameter(int: allowance)
+    )
+
+    tezosNodeClient.call(
+      contract: tokenContractAddress,
+      amount: amount,
+      entrypoint: EntryPoint.approve,
       parameter: parameter,
       source: source,
       signatureProvider: signatureProvider,