Change non-short circuiting and operator to short-circuiting and, or operator

src/Simpleflow/CodeGenerator/SimpleflowCodeVisitor.VisitExpression.Predicate.cs

@@ -58,10 +58,10 @@ public override Expression VisitLogicalExpression([NotNull] SimpleflowParser.Log
             switch (symbolType)
             {
                 case SimpleflowLexer.And:
-                    return Expression.And(left, right);
+                    return Expression.AndAlso(left, right);
 
                 case SimpleflowLexer.Or:
-                    return Expression.Or(left, right);
+                    return Expression.OrElse(left, right);
             }
 
             return null;

src/Simpleflow/Simpleflow.csproj

@@ -3,7 +3,7 @@
     <TargetFrameworks>net48;netcoreapp3.1;net6.0;</TargetFrameworks>
     <PackageIcon>PackageIcon.png</PackageIcon>
     <VersionPrefix>1.0.11</VersionPrefix>
-    <VersionSuffix>beta3</VersionSuffix>
+    <VersionSuffix>beta4</VersionSuffix>
     <PackageReadmeFile>README.md</PackageReadmeFile>
   </PropertyGroup>
 

test/Simpleflow.Tests/Scripting/PredicateStatementsTest.cs

@@ -3,7 +3,7 @@
 
 using Xunit;
 using Simpleflow.Tests.Helpers;
-
+using System.Collections.Generic;
 
 namespace Simpleflow.Tests.Scripting
 {
@@ -153,5 +153,30 @@ rule when d2 < d1 then
             Assert.Single(output.Messages);
         }
 
+
+        [Fact]
+        public void CheckShortCircuitingAndOperator()
+        {
+            // Arrange
+
+            var script =
+                @"
+                 rule when $exists(dict: arg, key: 'ContentType') and arg['ContentType'] == none then
+                     message 'got it'
+                ";
+
+            FlowOutput output = SimpleflowEngine.Run(script, 
+                new Dictionary<string, object> { {"test", null } }
+                , 
+                new FunctionRegister().Add("exists", (System.Func<IDictionary<string, object>, string, bool>)Exists));
+
+            Assert.Empty(output.Messages);
+        }
+
+        public static bool Exists(IDictionary<string, object> dict, string key)
+        {
+            return dict.ContainsKey(key);
+        }
+
     }
 }