Fix HasValueX incorrectly returning true

.editorconfig

@@ -84,6 +84,10 @@ spelling_checkable_types =            # NEW
 # Default Severity for all .NET Code Style rules below
 dotnet_analyzer_diagnostic.severity = warning
 
+# VSSpell001: Spell Check
+dotnet_diagnostic.VSSpell001.severity = suggestion
+dotnet_diagnostic.VSSpell002.severity = suggestion
+
 ##########################################
 # Language Rules - .NET
 # https://learn.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/language-rules
@@ -162,6 +166,7 @@ dotnet_diagnostic.IDE0063.severity = suggestion
 csharp_style_namespace_declarations = file_scoped
 csharp_style_prefer_method_group_conversion = true # NEW
 csharp_style_prefer_top_level_statements = true # NEW
+dotnet_diagnostic.IDE0290.severity = suggestion # NEW - Use primary constructor
 
 # Expression-bodied members
 csharp_style_expression_bodied_constructors = true
@@ -189,6 +194,11 @@ csharp_style_implicit_object_creation_when_type_is_apparent = true
 csharp_style_prefer_null_check_over_type_check = true
 csharp_style_prefer_tuple_swap = true # NEW
 csharp_style_prefer_utf8_string_literals = true # NEW
+dotnet_diagnostic.IDE0028.severity = suggestion # NEW - Use collection initializers
+dotnet_diagnostic.IDE0090.severity = suggestion # NEW - Simplify new expression
+dotnet_diagnostic.IDE0300.severity = suggestion # NEW - Collection initialization can be simplified
+dotnet_diagnostic.IDE0301.severity = suggestion # NEW - Collection initialization can be simplified
+dotnet_diagnostic.IDE0305.severity = suggestion # NEW - Collection initialization can be simplified
 
 # Modifier preferences
 csharp_preferred_modifier_order = public,private,protected,internal,static,extern,new,virtual,abstract,sealed,override,readonly,unsafe,volatile,async
@@ -294,6 +304,27 @@ csharp_space_between_square_brackets = false
 csharp_preserve_single_line_statements = false
 csharp_preserve_single_line_blocks = true
 
+##########################################
+# Code Quality Rules - C#
+# https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/quality-rules/
+##########################################
+
+[*.{cs,csx,cake}]
+
+# Usage rules
+# https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/quality-rules/usage-warnings
+dotnet_diagnostic.CA2249.severity = suggestion # NEW - Consider using String.Contains instead of String.IndexOf
+
+# Performance rules
+# https://learn.microsoft.com/en-us/dotnet/fundamentals/code-analysis/quality-rules/performance-warnings
+dotnet_diagnostic.CA1854.severity = suggestion # NEW - Prefer the IDictionary.TryGetValue(TKey, out TValue) method
+dotnet_diagnostic.CA1859.severity = suggestion # NEW - Use concrete types when possible for improved performance
+dotnet_diagnostic.CA1861.severity = suggestion # NEW - Avoid constant arrays as arguments
+dotnet_diagnostic.CA1865.severity = suggestion # NEW - Use 'string.Method(char)' instead of 'string.Method(string)' for string with single char
+dotnet_diagnostic.CA1866.severity = suggestion # NEW - Use 'string.Method(char)' instead of 'string.Method(string)' for string with single char
+dotnet_diagnostic.CA1867.severity = suggestion # NEW - Use 'string.Method(char)' instead of 'string.Method(string)' for string with single char
+dotnet_diagnostic.CA1869.severity = suggestion # NEW - Cache and reuse 'JsonSerializerOptions' instances
+
 ##########################################
 # .NET Naming Rules
 # https://learn.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/naming-rules

Source/Common/Values{T1,T2,T3,T4,T5,T6,T7}.cs

@@ -245,21 +245,21 @@ public Values(IEnumerable<object?> items)
             }
         }
 
-        this.HasValue1 = items1?.Count > 0;
-        this.HasValue2 = items2?.Count > 0;
-        this.HasValue3 = items3?.Count > 0;
-        this.HasValue4 = items4?.Count > 0;
-        this.HasValue5 = items5?.Count > 0;
-        this.HasValue6 = items6?.Count > 0;
-        this.HasValue7 = items7?.Count > 0;
-
         this.Value1 = items1 == null ? default : (OneOrMany<T1>)items1;
         this.Value2 = items2 == null ? default : (OneOrMany<T2>)items2;
         this.Value3 = items3 == null ? default : (OneOrMany<T3>)items3;
         this.Value4 = items4 == null ? default : (OneOrMany<T4>)items4;
         this.Value5 = items5 == null ? default : (OneOrMany<T5>)items5;
         this.Value6 = items6 == null ? default : (OneOrMany<T6>)items6;
         this.Value7 = items7 == null ? default : (OneOrMany<T7>)items7;
+
+        this.HasValue1 = this.Value1.Count > 0;
+        this.HasValue2 = this.Value2.Count > 0;
+        this.HasValue3 = this.Value3.Count > 0;
+        this.HasValue4 = this.Value4.Count > 0;
+        this.HasValue5 = this.Value5.Count > 0;
+        this.HasValue6 = this.Value6.Count > 0;
+        this.HasValue7 = this.Value7.Count > 0;
     }
 
     /// <summary>

Source/Common/Values{T1,T2,T3,T4,T5,T6}.cs

@@ -204,19 +204,19 @@ public Values(IEnumerable<object?> items)
             }
         }
 
-        this.HasValue1 = items1?.Count > 0;
-        this.HasValue2 = items2?.Count > 0;
-        this.HasValue3 = items3?.Count > 0;
-        this.HasValue4 = items4?.Count > 0;
-        this.HasValue5 = items5?.Count > 0;
-        this.HasValue6 = items6?.Count > 0;
-
         this.Value1 = items1 == null ? default : (OneOrMany<T1>)items1;
         this.Value2 = items2 == null ? default : (OneOrMany<T2>)items2;
         this.Value3 = items3 == null ? default : (OneOrMany<T3>)items3;
         this.Value4 = items4 == null ? default : (OneOrMany<T4>)items4;
         this.Value5 = items5 == null ? default : (OneOrMany<T5>)items5;
         this.Value6 = items6 == null ? default : (OneOrMany<T6>)items6;
+
+        this.HasValue1 = this.Value1.Count > 0;
+        this.HasValue2 = this.Value2.Count > 0;
+        this.HasValue3 = this.Value3.Count > 0;
+        this.HasValue4 = this.Value4.Count > 0;
+        this.HasValue5 = this.Value5.Count > 0;
+        this.HasValue6 = this.Value6.Count > 0;
     }
 
     /// <summary>

Source/Common/Values{T1,T2,T3,T4,T5}.cs

@@ -167,17 +167,17 @@ public Values(IEnumerable<object?> items)
             }
         }
 
-        this.HasValue1 = items1?.Count > 0;
-        this.HasValue2 = items2?.Count > 0;
-        this.HasValue3 = items3?.Count > 0;
-        this.HasValue4 = items4?.Count > 0;
-        this.HasValue5 = items5?.Count > 0;
-
         this.Value1 = items1 == null ? default : (OneOrMany<T1>)items1;
         this.Value2 = items2 == null ? default : (OneOrMany<T2>)items2;
         this.Value3 = items3 == null ? default : (OneOrMany<T3>)items3;
         this.Value4 = items4 == null ? default : (OneOrMany<T4>)items4;
         this.Value5 = items5 == null ? default : (OneOrMany<T5>)items5;
+
+        this.HasValue1 = this.Value1.Count > 0;
+        this.HasValue2 = this.Value2.Count > 0;
+        this.HasValue3 = this.Value3.Count > 0;
+        this.HasValue4 = this.Value4.Count > 0;
+        this.HasValue5 = this.Value5.Count > 0;
     }
 
     /// <summary>

Source/Common/Values{T1,T2,T3,T4}.cs

@@ -134,15 +134,15 @@ public Values(IEnumerable<object?> items)
             }
         }
 
-        this.HasValue1 = items1?.Count > 0;
-        this.HasValue2 = items2?.Count > 0;
-        this.HasValue3 = items3?.Count > 0;
-        this.HasValue4 = items4?.Count > 0;
-
         this.Value1 = items1 == null ? default : (OneOrMany<T1>)items1;
         this.Value2 = items2 == null ? default : (OneOrMany<T2>)items2;
         this.Value3 = items3 == null ? default : (OneOrMany<T3>)items3;
         this.Value4 = items4 == null ? default : (OneOrMany<T4>)items4;
+
+        this.HasValue1 = this.Value1.Count > 0;
+        this.HasValue2 = this.Value2.Count > 0;
+        this.HasValue3 = this.Value3.Count > 0;
+        this.HasValue4 = this.Value4.Count > 0;
     }
 
     /// <summary>

Source/Common/Values{T1,T2,T3}.cs

@@ -105,13 +105,13 @@ public Values(IEnumerable<object> items)
             }
         }
 
-        this.HasValue1 = items1?.Count > 0;
-        this.HasValue2 = items2?.Count > 0;
-        this.HasValue3 = items3?.Count > 0;
-
         this.Value1 = items1 == null ? default : (OneOrMany<T1>)items1;
         this.Value2 = items2 == null ? default : (OneOrMany<T2>)items2;
         this.Value3 = items3 == null ? default : (OneOrMany<T3>)items3;
+
+        this.HasValue1 = this.Value1.Count > 0;
+        this.HasValue2 = this.Value2.Count > 0;
+        this.HasValue3 = this.Value3.Count > 0;
     }
 
     /// <summary>

Source/Common/Values{T1,T2}.cs

@@ -80,11 +80,11 @@ public Values(IEnumerable<object?> items)
             }
         }
 
-        this.HasValue1 = items1?.Count > 0;
-        this.HasValue2 = items2?.Count > 0;
-
         this.Value1 = items1 == null ? default : (OneOrMany<T1>)items1;
         this.Value2 = items2 == null ? default : (OneOrMany<T2>)items2;
+
+        this.HasValue1 = this.Value1.Count > 0;
+        this.HasValue2 = this.Value2.Count > 0;
     }
 
     /// <summary>

Tests/Schema.NET.Test/AssertEx.cs

@@ -0,0 +1,18 @@
+namespace Schema.NET.Test;
+
+using System.Collections;
+using Xunit;
+
+/// <summary>
+/// Provides extended methods and helpers to the Xunit.Assert class.
+/// </summary>
+[System.Diagnostics.CodeAnalysis.SuppressMessage("Naming", "CA1711:Identifiers should not have incorrect suffix", Justification = "Name needs to be short to ensure readability of consuming code.")]
+public static class AssertEx
+{
+    /// <summary>
+    /// Verifies that a <see cref="OneOrMany{T}"/> collection is empty.
+    /// </summary>
+    /// <typeparam name="T">The type of the values.</typeparam>
+    /// <inheritdoc cref="Assert.Empty(IEnumerable)"/>
+    public static void Empty<T>(OneOrMany<T> collection) => Assert.Empty(collection);
+}

Tests/Schema.NET.Test/OneOrManyTest.cs

@@ -60,7 +60,7 @@ public void Constructor_NullList_ThrowsArgumentNullException() =>
     public void Count_DefaultStructConstructor_ReturnsZero() => Assert.Empty(default(OneOrMany<int>));
 
     [Fact]
-    public void Count_DefaultClassConstructor_ReturnsZero() => Assert.Empty(default(OneOrMany<string>)!);
+    public void Count_DefaultClassConstructor_ReturnsZero() => AssertEx.Empty(default(OneOrMany<string>));
 
     [Fact]
     public void Count_NullItem_ReturnsZero() => Assert.Empty(new OneOrMany<int?>((int?)null));

Tests/Schema.NET.Test/Values2Test.cs

@@ -15,7 +15,7 @@ public void Constructor_Value1Passed_OnlyValue1HasValue()
         Assert.True(values.HasValue1);
         Assert.Single(values.Value1);
         Assert.False(values.HasValue2);
-        Assert.Empty(values.Value2!);
+        AssertEx.Empty(values.Value2);
         Assert.Equal(new List<object>() { 1 }, values.Cast<object>().ToList());
     }
 
@@ -43,6 +43,23 @@ public void Constructor_Items_HasAllItems()
         Assert.Equal(new List<object>() { 1, "Foo" }, values.Cast<object>().ToList());
     }
 
+    [Fact]
+    public void Constructor_StringItems_NullOrWhitespaceDoesntHaveValue()
+    {
+        object[] nullOrWhitespaceValues = new[]
+        {
+            string.Empty,
+            null!,
+            "\u2028 \u2029 \u0009 \u000A \u000B \u000C \u000D \u0085",
+        };
+        var values = new Values<int, string>(nullOrWhitespaceValues);
+
+        Assert.False(values.HasValue1);
+        Assert.Empty(values.Value1);
+        Assert.False(values.HasValue2, $"{nameof(values.HasValue2)}: Expected: False, Actual: True");
+        AssertEx.Empty(values.Value2);
+    }
+
     [Fact]
     public void Constructor_NullList_ThrowsArgumentNullException() =>
         Assert.Throws<ArgumentNullException>(() => new Values<int, string>((List<object>)null!));
@@ -88,7 +105,7 @@ public void ImplicitConversionOperator_Value1Passed_OnlyValue1HasValue()
         Assert.True(values.HasValue1);
         Assert.Single(values.Value1);
         Assert.False(values.HasValue2);
-        Assert.Empty(values.Value2!);
+        AssertEx.Empty(values.Value2);
         Assert.Equal(new List<object>() { 1 }, values.Cast<object>().ToList());
     }
 
@@ -112,7 +129,7 @@ public void ImplicitConversionOperator_Value1ListPassed_OnlyValue1HasValue()
         Assert.True(values.HasValue1);
         Assert.Equal(2, values.Value1.Count);
         Assert.False(values.HasValue2);
-        Assert.Empty(values.Value2!);
+        AssertEx.Empty(values.Value2);
         Assert.Equal(new List<object>() { 1, 2 }, values.Cast<object>().ToList());
     }
 

Tests/Schema.NET.Test/Values3Test.cs

@@ -15,7 +15,7 @@ public void Constructor_Value1Passed_OnlyValue1HasValue()
         Assert.True(values.HasValue1);
         Assert.Single(values.Value1);
         Assert.False(values.HasValue2);
-        Assert.Empty(values.Value2!);
+        AssertEx.Empty(values.Value2);
         Assert.Equal(new List<object>() { 1 }, values.Cast<object>().ToList());
     }
 
@@ -39,7 +39,7 @@ public void Constructor_Value3Passed_OnlyValue3HasValue()
         Assert.False(values.HasValue1);
         Assert.Empty(values.Value1);
         Assert.False(values.HasValue2);
-        Assert.Empty(values.Value2!);
+        AssertEx.Empty(values.Value2);
         Assert.True(values.HasValue3);
         Assert.Single(values.Value3);
         Assert.Equal(new List<object>() { DayOfWeek.Friday }, values.Cast<object>().ToList());
@@ -59,6 +59,25 @@ public void Constructor_Items_HasAllItems()
         Assert.Equal(new List<object>() { 1, "Foo", DayOfWeek.Friday }, values.Cast<object>().ToList());
     }
 
+    [Fact]
+    public void Constructor_StringItems_NullOrWhitespaceDoesntHaveValue()
+    {
+        object[] nullOrWhitespaceValues = new[]
+        {
+            string.Empty,
+            null!,
+            "\u2028 \u2029 \u0009 \u000A \u000B \u000C \u000D \u0085",
+        };
+        var values = new Values<int, string, DayOfWeek>(nullOrWhitespaceValues);
+
+        Assert.False(values.HasValue1);
+        Assert.Empty(values.Value1);
+        Assert.False(values.HasValue2, $"{nameof(values.HasValue2)}: Expected: False, Actual: True");
+        AssertEx.Empty(values.Value2);
+        Assert.False(values.HasValue3);
+        Assert.Empty(values.Value3);
+    }
+
     [Fact]
     public void Constructor_NullList_ThrowsArgumentNullException() =>
         Assert.Throws<ArgumentNullException>(() => new Values<int, string, DayOfWeek>((List<object>)null!));
@@ -119,7 +138,7 @@ public void ImplicitConversionOperator_Value1Passed_OnlyValue1HasValue()
         Assert.True(values.HasValue1);
         Assert.Single(values.Value1);
         Assert.False(values.HasValue2);
-        Assert.Empty(values.Value2!);
+        AssertEx.Empty(values.Value2);
         Assert.Equal(new List<object>() { 1 }, values.Cast<object>().ToList());
     }
 
@@ -143,7 +162,7 @@ public void ImplicitConversionOperator_Value3Passed_OnlyValue3HasValue()
         Assert.False(values.HasValue1);
         Assert.Empty(values.Value1);
         Assert.False(values.HasValue2);
-        Assert.Empty(values.Value2!);
+        AssertEx.Empty(values.Value2);
         Assert.True(values.HasValue3);
         Assert.Single(values.Value3);
         Assert.Equal(new List<object>() { DayOfWeek.Friday }, values.Cast<object>().ToList());
@@ -157,7 +176,7 @@ public void ImplicitConversionOperator_Value1CollectionPassed_OnlyValue1HasValue
         Assert.True(values.HasValue1);
         Assert.Equal(2, values.Value1.Count);
         Assert.False(values.HasValue2);
-        Assert.Empty(values.Value2!);
+        AssertEx.Empty(values.Value2);
         Assert.Equal(new List<object>() { 1, 2 }, values.Cast<object>().ToList());
     }
 
@@ -181,7 +200,7 @@ public void ImplicitConversionOperator_Value3CollectionPassed_OnlyValue3HasValue
         Assert.False(values.HasValue1);
         Assert.Empty(values.Value1);
         Assert.False(values.HasValue2);
-        Assert.Empty(values.Value2!);
+        AssertEx.Empty(values.Value2);
         Assert.True(values.HasValue3);
         Assert.Equal(2, values.Value3.Count);
         Assert.Equal(new List<object>() { DayOfWeek.Friday, DayOfWeek.Monday }, values.Cast<object>().ToList());