Fix ArgumentException for arrays with different types of values #210 (#214)

* Fix ArgumentException for arrays with different types of values #210

Author: b0bi79

ClosedXML.Report/FormulaEvaluator.cs

@@ -78,7 +78,8 @@ private string Trim(string formula)
 
         internal Delegate ParseExpression(string formula, ParameterExpression[] parameters)
         {
-            if (!_lambdaCache.TryGetValue(formula, out var lambda))
+            var cacheKey = GetCacheKey(formula, parameters);
+            if (!_lambdaCache.TryGetValue(cacheKey, out var lambda))
             {
                 try
                 {
@@ -89,11 +90,16 @@ internal Delegate ParseExpression(string formula, ParameterExpression[] paramete
                     return null;
                 }
 
-                _lambdaCache.Add(formula, lambda);
+                _lambdaCache.Add(cacheKey, lambda);
             }
             return lambda;
         }
 
+        private string GetCacheKey(string formula, ParameterExpression[] parameters)
+        {
+            return formula + string.Join("+", parameters.Select(x => x.Type.Name));
+        }
+
         private object Eval(string expression, Parameter[] pars)
         {
             var parameters = pars.Select(p => p.ParameterExpression).ToArray();

tests/ClosedXML.Report.Tests/FormulaEvaluatorTests.cs

@@ -99,7 +99,7 @@ public void ExpressionParseTestNullPropagation()
             eval.Evaluate(@"{{np(b.Manager.Name, null)}}").Should().BeNull();
         }
 
-        [Fact(Skip = "It doesn't work yet")]
+        [Fact]
         public void EvalDictionaryParams()
         {
             Parameter CreateDicParameter(string name) => new Parameter("item", new Dictionary<string, object>
@@ -110,7 +110,7 @@ public void EvalDictionaryParams()
             eval.Evaluate("{{item.Name.FirstName}}", CreateDicParameter("John")).Should().Be("John");
         }
 
-        [Fact(Skip = "It doesn't work yet")]
+        [Fact]
         public void EvalDictionaryParams2()
         {
             object CreateDicParameter(string name) => new Dictionary<string, object>
@@ -134,6 +134,25 @@ public void UsingDynamicLinqTypeTest()
             eval.Evaluate("{{EvaluateUtils.ParseAsInt(a).IncrementMe()}}").Should().Be(2);
         }
 
+        [Fact]
+        public void EvalMixedArray()
+        {
+            var mixed = new object[] {
+                "string",
+                1,
+                0.1,
+                System.DateTime.Today,
+            };
+
+            var eval = new FormulaEvaluator();
+            eval.AddVariable("mixed", mixed);
+            eval.Evaluate("{{mixed.Count()}}").Should().Be(4);
+            foreach (var item in mixed)
+            {
+                eval.Evaluate("{{item}}", new Parameter("item", item));
+            }
+        }
+
         class Customer
         {
             public int Id { get; set; }