Check tx proposal minimum amount

config.js

@@ -11,7 +11,8 @@ var defaultConfig = {
   // wallet limits
   limits: {
     totalCopayers: 12,
-    mPlusN: 100
+    mPlusN: 100,
+    minAmountSatoshi: 5400,
   },
 
   // network layer (PeerJS) config

js/controllers/send.js

@@ -8,6 +8,7 @@ angular.module('copayApp.controllers').controller('SendController',
     var satToUnit = 1 / config.unitToSatoshi;
     $scope.defaultFee = bitcore.TransactionBuilder.FEE_PER_1000B_SAT * satToUnit;
     $scope.unitToBtc = config.unitToSatoshi / bitcore.util.COIN;
+    $scope.minAmount = config.limits.minAmountSatoshi * satToUnit;
 
     $scope.loadTxs = function() {
       var opts = {

js/models/core/Wallet.js

@@ -1534,6 +1534,7 @@ Wallet.prototype.createTxSync = function(toAddress, amountSatStr, comment, utxos
   preconditions.checkArgument(new Address(toAddress).network().name === this.getNetworkName(), 'networkname mismatch');
   preconditions.checkState(pkr.isComplete(), 'pubkey ring incomplete');
   preconditions.checkState(priv, 'no private key');
+  preconditions.checkArgument(bignum(amountSatStr, 10).cmp(copayConfig.limits.minAmountSatoshi) >= 0, 'invalid amount');
   if (comment) preconditions.checkArgument(comment.length <= 100);
 
   if (!opts.remainderOut) {

test/test.Wallet.js

@@ -630,7 +630,7 @@ describe('Wallet model', function() {
     return utxo;
   };
   var toAddress = 'mjfAe7YrzFujFf8ub5aUrCaN5GfSABdqjh';
-  var amountSatStr = '1000';
+  var amountSatStr = '10000';
 
   it('should create transaction', function(done) {
     var w = cachedCreateW2();
@@ -641,6 +641,7 @@ describe('Wallet model', function() {
       done();
     });
   });
+
   it('should create & sign transaction from received funds', function(done) {
     var k2 = new PrivateKey({
       networkName: config.networkName
@@ -724,6 +725,23 @@ describe('Wallet model', function() {
     });
   });
 
+  describe('#createTxSync', function () {
+    it('should fail if amount below min value', function() {
+      var w = cachedCreateW2();
+      var utxo = createUTXO(w);
+
+      var badCreate = function() {
+        w.createTxSync(
+          'mgGJEugdPnvhmRuFdbdQcFfoFLc1XXeB79',
+          '123',
+          null,
+          utxo
+        );
+      }
+      chai.expect(badCreate).to.throw('invalid amount');
+    });
+  });
+
   describe('#send', function() {
     it('should call this.network.send', function() {
       var w = cachedCreateW2();

views/send.html

@@ -67,7 +67,7 @@
                 <input type="number" id="amount"
                 ng-disabled="loading || ($root.merchant && +$root.merchant.total > 0) || $root.merchantError"
                 name="amount" placeholder="Amount" ng-model="amount"
-                min="0.00005400" max="10000000000" enough-amount required
+                min="{{minAmount}}" max="10000000000" enough-amount required
                 autocomplete="off"
                 >
                 <small class="icon-input" ng-show="!sendForm.amount.$invalid && amount"><i class="fi-check"></i></small>