Fix #756: Preconditions Invalid Argument

lib/errors/spec.js

@@ -27,7 +27,7 @@ module.exports = [{
     message: format('Invalid network: must be "livenet" or "testnet", got {0}')
   }, {
     name: 'InvalidArgument',
-    message: format('Invalid Argument {0}, {1}')
+    message: format('Invalid Argument' + '\' + (arguments[0] ? \': {0}\' : \'\') + \'')
   }, {
     name: 'AbstractMethodInvoked',
     message: format('Abstract Method Invokation: {0}')

test/util/preconditions.js

@@ -61,4 +61,19 @@ describe('preconditions', function() {
       $.checkArgumentType(new PrivateKey(), PrivateKey);
     }).should.not.throw();
   });
+
+  it('formats correctly a message on InvalidArgument()', function() {
+    var error = new errors.InvalidArgument();
+    error.message.should.equal('Invalid Argument');
+  });
+
+  it('formats correctly a message on checkArgument', function() {
+    var error;
+    try {
+      $.checkArgument(null, 'parameter must be provided');
+    } catch (e) {
+      error = e;
+    }
+    error.message.should.equal('Invalid Argument: parameter must be provided');
+  });
 });