IExpressionNode basic implementations.

VAR.ExpressionEvaluator.Tests/ExpressionStringNodeTests.cs

@@ -0,0 +1,30 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace VAR.ExpressionEvaluator.Tests
+{
+    [TestClass()]
+    public class ExpressionStringNodeTests
+    {
+        [TestMethod()]
+        public void ExpressionNumberNode__Hello()
+        {
+            IExpressionNode node = new ExpressionStringNode("Hello");
+            Assert.AreEqual("Hello", node.Eval());
+        }
+
+        [TestMethod()]
+        public void ExpressionNumberNode__World()
+        {
+            IExpressionNode node = new ExpressionStringNode("World");
+            Assert.AreEqual("World", node.Eval());
+        }
+
+        [TestMethod()]
+        public void ExpressionNumberNode__Hello_World()
+        {
+            IExpressionNode node = new ExpressionStringNode("Hello World");
+            Assert.AreEqual("Hello World", node.Eval());
+        }
+
+    }
+}