Fixed crash which occured when fetchXml parameter evaluated to null (even when fetch was not executed)

Florian Krönert · Florian Krönert · commit 259ac7923d12 · 2020-08-13T16:12:20.000+02:00
diff --git a/src/lib/Xrm.Oss.XTL.Interpreter/FunctionHandlers.cs b/src/lib/Xrm.Oss.XTL.Interpreter/FunctionHandlers.cs
@@ -626,10 +626,10 @@ private static int Compare(List<ValueExpression> parameters)
 
                 if (referenceNumber >= references.Count)
                 {
-                    throw new InvalidPluginExecutionException($"You tried using reference {referenceNumber} in fetch, but there are less reference inputs than that. You should probably wrap this fetch inside an if condition and only execute it, if your reference is non-null.");
+                    throw new InvalidPluginExecutionException($"You tried using reference {referenceNumber} in fetch, but there are less reference inputs than that. Please check your reference number or your reference input array.");
                 }
 
-                return references[referenceNumber].ToString();
+                return references[referenceNumber]?.ToString();
             });
 
             tracing.Trace("References replaced");
diff --git a/src/test/Xrm.Oss.XTL.Interpreter.Tests/XTLInterpreterTests.cs b/src/test/Xrm.Oss.XTL.Interpreter.Tests/XTLInterpreterTests.cs
@@ -693,6 +693,41 @@ public void It_Should_Parse_Dictionaries()
             Assert.That(result, Is.EqualTo("retrieveLabels: True, returnOptionSetValue: False"));
         }
 
+        [Test]
+        public void It_Should_Not_Fail_On_Complex_Template_Field()
+        {
+            var context = new XrmFakedContext();
+            var service = context.GetFakedOrganizationService();
+            var tracing = context.GetFakeTracingService();
+
+            var formula = @"If (
+    IsNull(Value(""oss_htmltemplate"")),
+    Value(""oss_subject"", { explicitTarget: First(Fetch(""<fetch no-lock='true'><entity name='oss_htmltemplate'><attribute name='oss_subject' /><filter><condition attribute='oss_uniquename' operator='eq' value='{1}' /></filter></entity></fetch>"", [Value(""oss_htmltemplateuniquename"")])) }),
+    Value(""oss_htmltemplate.oss_subject"")
+)";
+
+            var template = new Entity
+            {
+                Id = Guid.NewGuid(),
+                LogicalName = "oss_htmltemplate",
+                ["oss_uniquename"] = "tst",
+                ["oss_subject"] = "Test",
+                ["oss_html"] = "<html />"
+            };
+
+            var email = new Entity
+            {
+                LogicalName = "email",
+                ["oss_htmltemplate"] = template.ToEntityReference()
+            };
+
+            context.Initialize(template);
+
+            var result = new XTLInterpreter(formula, email, null, service, tracing).Produce();
+
+            Assert.That(result, Is.EqualTo("Test"));
+        }
+
         [Test]
         public void First_Should_Work_On_Entity_Collection()
         {

Original file line number	Diff line number	Diff line change
`@@ -626,10 +626,10 @@ private static int Compare(List<ValueExpression> parameters)`
`626`	`626`
`627`	`627`	`if (referenceNumber >= references.Count)`
`628`	`628`	`{`
`629`		`- throw new InvalidPluginExecutionException($"You tried using reference {referenceNumber} in fetch, but there are less reference inputs than that. You should probably wrap this fetch inside an if condition and only execute it, if your reference is non-null.");`
	`629`	`+ throw new InvalidPluginExecutionException($"You tried using reference {referenceNumber} in fetch, but there are less reference inputs than that. Please check your reference number or your reference input array.");`
`630`	`630`	`}`
`631`	`631`
`632`		`- return references[referenceNumber].ToString();`
	`632`	`+ return references[referenceNumber]?.ToString();`
`633`	`633`	`});`
`634`	`634`
`635`	`635`	`tracing.Trace("References replaced");`