create separate function for secure send

lib/modules/blockchain_connector/index.js

@@ -230,7 +230,7 @@ class BlockchainConnector {
     }).catch(cb);
   }
 
-  deployContractFromObject(deployContractObject, params, cb) {
+  secureSend(toSend, params, cb) {
     const self = this;
     let hash;
     let calledBacked = false;
@@ -263,28 +263,37 @@ class BlockchainConnector {
       });
     }, 500);
 
-    deployContractObject.send({
-      from: params.from, gas: params.gas, gasPrice: params.gasPrice
-    }, function (err, transactionHash) {
+    toSend.estimateGas()
+      .then(gasEstimated => {
+        params.gas = gasEstimated + 1000;
+        params.from = params.from || self.defaultAccount();
+        return toSend.send(params, function(err, transactionHash) {
           if (err) {
             return callback(err);
           }
           hash = transactionHash;
-    }).on('receipt', function (receipt) {
+        }).on('receipt', function(receipt) {
           if (receipt.contractAddress !== undefined) {
             callback(null, receipt);
           }
-    }).then(function (_contract) {
+        }).then(function(_contract) {
           if (!hash) {
             return; // Somehow we didn't get the receipt yet... Interval will catch it
           }
           self.web3.eth.getTransactionReceipt(hash, callback);
         }).catch(callback);
+      });
+  }
+
+  deployContractFromObject(deployContractObject, params, cb) {
+    this.secureSend(deployContractObject, {
+      from: params.from, gas: params.gas, gasPrice: params.gasPrice
+    }, cb);
   }
 
   determineDefaultAccount(cb) {
     const self = this;
-    self.getAccounts(function (err, accounts) {
+    self.getAccounts(function(err, accounts) {
       if (err) {
         self.logger.error(err);
         return cb(new Error(err));