Properly handle scopes

UpsilonTests/ScopeTests.cs

@@ -0,0 +1,44 @@
+using Upsilon.BaseTypes.Number;
+using Upsilon.Evaluator;
+using Xunit;
+
+namespace UpsilonTests
+{
+    public class ScopeTests
+    {
+        [Fact]
+        public void LocalInnerScopeDoesNotOverrideGlobal()
+        {
+            const string input = @"
+a = 10
+if true then
+    local a = 100
+end
+b = a
+";
+            var script = new Script(input);
+            Assert.Empty(script.Diagnostics.Messages);
+            var evaluate = script.Evaluate<NumberLong>();
+            Assert.Empty(script.Diagnostics.Messages);
+            Assert.Equal((long)10, evaluate);
+        }
+
+        [Fact]
+        public void InnerScopeDoesOverrideGlobal()
+        {
+            const string input = @"
+a = 10
+if true then
+    a = 100
+end
+b = a
+";
+            var script = new Script(input);
+            Assert.Empty(script.Diagnostics.Messages);
+            var evaluate = script.Evaluate<NumberLong>();
+            Assert.Empty(script.Diagnostics.Messages);
+            Assert.Equal((long)100, evaluate);
+        }
+
+    }
+}

UpsilonTests/UpsilonTests.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
         <TargetFramework>netcoreapp2.1</TargetFramework>