Fix/exception on aggregate call fix

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+[1.8.6] - 2022-01-25
+### Fixed
+- Error when calling Aggregate() to generate message for DropdownWrapper
+
 [1.8.5] - 2022-01-27
 ### Changed
 - Bindings code refactoring

src/Behavioral.Automation/Behavioral.Automation.csproj

@@ -16,7 +16,7 @@ The whole automation code is divided into the following parts:
 - UI structure descriptive code
 - Supportive code</Description>
         <Copyright>Quantori Inc.</Copyright>
-        <PackageVersion>1.8.5</PackageVersion>
+        <PackageVersion>1.8.6</PackageVersion>
         <RepositoryUrl>https://github.com/quantori/Behavioral.Automation</RepositoryUrl>
         <PublishRepositoryUrl>true</PublishRepositoryUrl>
         <IncludeSymbols>true</IncludeSymbols>

src/Behavioral.Automation/Bindings/DropdownBinding.cs

@@ -4,6 +4,7 @@
 using Behavioral.Automation.Elements;
 using Behavioral.Automation.FluentAssertions;
 using Behavioral.Automation.Model;
+using Behavioral.Automation.Services;
 using JetBrains.Annotations;
 using TechTalk.SpecFlow;
 
@@ -92,7 +93,7 @@ public void CheckDropdownContainsItems(
             Assert.ShouldBecome(
                 () => wrapper.Items.Contains(value),
                 !behavior.Contains("not"),
-                $"{wrapper.Caption} items are {wrapper.Items.Aggregate((x, y) => $"{x}, {y}")}");
+                wrapper.Items.CreateDropdownErrorMessage(wrapper.Caption));
         }
 
         /// <summary>
@@ -111,15 +112,15 @@ public void CheckDropdownContainsItems(
         [Then("the \"(.*?)\" menu should (contain|not contain) the following values:")]
         public void CheckDropdownContainsMultipleItems([NotNull] IDropdownWrapper wrapper, [NotNull] string behavior, [NotNull] Table table)
         {
-            Assert.ShouldBecome(() => table.Rows.Any(), true,
+            Assert.ShouldBecome(()=> table.Rows.Any(),true, 
                 new AssertionBehavior(AssertionType.Immediate, false), "Please provide data in the table");
 
-            var dropdownItems = wrapper.Items;
+            var dropdownItems = wrapper.Items.ToArray();
             foreach (var row in table.Rows)
             {
                 var value = row.Values.FirstOrDefault();
-                Assert.ShouldBecome(() => dropdownItems.Contains(value), !behavior.Contains("not"),
-                $"{wrapper.Caption} items are {dropdownItems.Aggregate((x, y) => $"{x}, {y}")}");
+                Assert.ShouldBecome(()=>dropdownItems.Contains(value), !behavior.Contains("not"),
+                dropdownItems.CreateDropdownErrorMessage(wrapper.Caption));
             }
         }
 
@@ -140,7 +141,7 @@ public void CheckAllItemsContainString(
             Assert.ShouldBecome(() => wrapper.Stale, false, $"{wrapper.Caption} is stale");
             var items = wrapper.Items;
             Assert.ShouldBecome(() => wrapper.Items.All(x => x.ToLower().Contains(value.ToLower().Trim())),
-                !behavior.Contains("not"), $"{wrapper.Caption} items are {items.Aggregate((x, y) => $"{x}, {y}")}");
+                !behavior.Contains("not"), items.CreateDropdownErrorMessage(wrapper.Caption));
         }
 
         /// <summary>
@@ -258,7 +259,7 @@ private void CheckDropdownValueCollectionEnabled([NotNull] string behavior,
         [Then("no values should be selected in (.*?):")]
         public void CheckMultiSelectDropdownHasNoValuesSelected([NotNull] IMultiSelectDropdownWrapper wrapper)
         {
-            Assert.ShouldBecome(() => !wrapper.SelectedValuesTexts.Any(), true, $"{wrapper.Caption} has the following values : {wrapper.SelectedValuesTexts.Aggregate((x, y) => $"{x}, {y}")}");
+            Assert.ShouldBecome(() => !wrapper.SelectedValuesTexts.Any(), true, wrapper.SelectedValuesTexts.CreateDropdownErrorMessage(wrapper.Caption));
         }
 
         /// <summary>

src/Behavioral.Automation/Services/PrintValuesHelper.cs

@@ -17,5 +17,20 @@ public static string GetPrintableValues([NotNull] this IEnumerable<ITableRowWrap
 
             return "\r\n Rows collection was empty";
         }
+
+        /// <summary>
+        /// Method that returns error message with elements aggregation 
+        /// </summary>
+        /// <param name="caption">wrapper caption</param>
+        /// <param name="items">collection of dropdown elements in string form</param>
+        /// <returns>Error message with actual collection items</returns>
+        public static string CreateDropdownErrorMessage(this IEnumerable<string> items, string caption)
+        {
+            caption ??= "Collection";
+            if (items == null || !items.Any())
+                return $"'{caption}' is empty";
+
+            return $"Actual '{caption}' items are: {items.Aggregate((x, y) => $"{x}, {y}")}";
+        }
     }
 }