Feature/option equality (#40)

* Add option equality and spec * Inc minor due to new methods * Rm empty lines * Rename var * more option equality specs * expression bodies * optimize option GetHashCode, more tests * - different typed null valued options have different hashcodes --------- Co-authored-by: Alexander Wiedemann <[email protected]>
bluehands · Apr 12, 2024 · 64aa095 · 64aa095
1 parent 824464d
commit 64aa095
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Showing 4 changed files with 117 additions and 2 deletions.
diff --git a/Source/FunicularSwitch.sln.DotSettings b/Source/FunicularSwitch.sln.DotSettings
@@ -1,4 +1,6 @@
 <wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=TypesAndNamespaces/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="AaBb_AaBb"&gt;&lt;ExtraRule Prefix="" Suffix="" Style="AaBb_aaBb" /&gt;&lt;ExtraRule Prefix="" Suffix="" Style="aaBb_aaBb" /&gt;&lt;/Policy&gt;</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/UserRules/=a0b4bc4d_002Dd13b_002D4a37_002Db37e_002Dc9c6864e4302/@EntryIndexedValue">&lt;Policy&gt;&lt;Descriptor Staticness="Any" AccessRightKinds="Any" Description="Types and namespaces"&gt;&lt;ElementKinds&gt;&lt;Kind Name="NAMESPACE" /&gt;&lt;Kind Name="CLASS" /&gt;&lt;Kind Name="STRUCT" /&gt;&lt;Kind Name="ENUM" /&gt;&lt;Kind Name="DELEGATE" /&gt;&lt;/ElementKinds&gt;&lt;/Descriptor&gt;&lt;Policy Inspect="True" Prefix="" Suffix="" Style="AaBb_AaBb"&gt;&lt;ExtraRule Prefix="" Suffix="" Style="AaBb_aaBb" /&gt;&lt;ExtraRule Prefix="" Suffix="" Style="aaBb_aaBb" /&gt;&lt;/Policy&gt;&lt;/Policy&gt;</s:String>
+	<s:Boolean x:Key="/Default/Environment/SettingsMigration/IsMigratorApplied/=JetBrains_002EReSharper_002EPsi_002ECSharp_002ECodeStyle_002ESettingsUpgrade_002EPredefinedNamingRulesToUserRulesUpgrade/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=switchyard/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=Usings/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>
diff --git a/Source/FunicularSwitch/FunicularSwitch.csproj b/Source/FunicularSwitch/FunicularSwitch.csproj
@@ -14,7 +14,7 @@
 
 		<!--#region adapt versions here-->
 		<MajorVersion>6</MajorVersion>
-		<MinorAndPatchVersion>0.0</MinorAndPatchVersion>
+		<MinorAndPatchVersion>1.0</MinorAndPatchVersion>
 		<!--#endregion-->
 
 		<AssemblyVersion>$(MajorVersion).0.0</AssemblyVersion>

diff --git a/Source/FunicularSwitch/Option.cs b/Source/FunicularSwitch/Option.cs
@@ -15,7 +15,7 @@ public static class Option
         public static Task<Option<T>> NoneAsync<T>() => Task.FromResult(Option<T>.None);
     }
 
-    public readonly struct Option<T> : IEnumerable<T>
+    public readonly struct Option<T> : IEnumerable<T>, IEquatable<Option<T>>
     {
         public static readonly Option<T> None = default;
 
@@ -111,6 +111,25 @@ public async Task<TResult> Match<TResult>(Func<T, Task<TResult>> some, TResult n
         public Option<TOther> Convert<TOther>() => Match(s => Option<TOther>.Some((TOther)(object)s!), Option<TOther>.None);
 
         public override string ToString() => Match(v => v?.ToString() ?? "", () => $"None {typeof(T).BeautifulName()}");
+
+        public bool Equals(Option<T> other) => _isSome == other._isSome && EqualityComparer<T>.Default.Equals(_value, other._value);
+
+        public override bool Equals(object? obj) => obj is Option<T> other && Equals(other);
+
+        public override int GetHashCode()
+        {
+            unchecked
+            {
+                var hashCode = _isSome.GetHashCode();
+                hashCode = (hashCode * 397) ^ EqualityComparer<T>.Default.GetHashCode(_value);
+                hashCode = (hashCode * 397) ^ typeof(T).GetHashCode();
+                return hashCode;
+            }
+        }
+
+        public static bool operator ==(Option<T> left, Option<T> right) => left.Equals(right);
+
+        public static bool operator !=(Option<T> left, Option<T> right) => !left.Equals(right);
     }
 
     public static class OptionExtension

diff --git a/Source/Tests/FunicularSwitch.Test/OptionSpecs.cs b/Source/Tests/FunicularSwitch.Test/OptionSpecs.cs
@@ -126,4 +126,98 @@ from r1 in some
 			select x
 		)).Should().BeEquivalentTo(await someAsync.Map(r => r * 2));
 	}
+
+	[TestMethod]
+	public void ShouldHaveDifferentHashCodeIfBothValuesAreDifferent()
+	{
+		var hashcode1 = Some(1).GetHashCode();
+		var hashcode2 = Some(2).GetHashCode();
+		hashcode1.Should().NotBe(hashcode2);
+	}
+
+    [TestMethod]
+    public void ShouldNotBeEqualIfValuesDifferent()
+    {
+        var some1 = Some(1);
+        var some2 = Some(2);
+        some1.Equals(some2).Should().BeFalse();
+        (some1 == some2).Should().BeFalse();
+        (some1 != some2).Should().BeTrue();
+    }
+
+	[TestMethod]
+	public void ShouldHaveSameHashCodeIfBothValueAreSame()
+	{
+		var hashcode1 = Some(1).GetHashCode();
+		var hashcode2 = Some(1).GetHashCode();
+		hashcode1.Should().Be(hashcode2);
+	}
+
+	[TestMethod]
+	public void ShouldHaveDifferentHashCodeIfOneIsNone()
+	{
+		var hashcode1 = Some(1).GetHashCode();
+		var hashcode2 = None<int>().GetHashCode();
+		hashcode1.Should().NotBe(hashcode2);
+	}
+
+	[TestMethod]
+	public void ShouldBeEqualIfBothValuesAreEqual()
+	{
+		var some1 = Some(1);
+		var some2 = Some(1);
+		some1.Equals(some2).Should().BeTrue();
+        (some1 == some2).Should().BeTrue();
+        (some1 != some2).Should().BeFalse();
+    }
+
+	[TestMethod]
+	public void ShouldNotBeEqualIfOneIsNone()
+	{
+		var some = Some(1);
+		var none = None<int>();
+		some.Equals(none).Should().BeFalse();
+	}
+
+    [TestMethod]
+    public void ShouldBeEqualIfBothAreNoneOfSameType()
+    {
+        None<int>().Equals(None<int>()).Should().BeTrue();
+    }
+
+    [TestMethod]
+    public void ShouldHaveSameHashCodeIfBothAreNoneOfSameTypes()
+    {
+        None<string>().GetHashCode().Equals(None<string>().GetHashCode()).Should().BeTrue();
+    }
+
+    [TestMethod]
+    public void ShouldNotBeEqualIfBothAreNoneOfDifferentTypes()
+    {
+        // ReSharper disable once SuspiciousTypeConversion.Global
+        None<int>().Equals(None<string>()).Should().BeFalse();
+    }
+
+    [TestMethod]
+    public void ShouldNotHaveSameHashCodeIfBothAreNoneOfDifferentTypes()
+    {
+        // ReSharper disable once SuspiciousTypeConversion.Global
+        None<int>().GetHashCode().Equals(None<string>().GetHashCode()).Should().BeFalse();
+    }
+
+    [TestMethod]
+    public void NullOptionsWork()
+    {
+        var nullOption = Option<MyClass?>.Some(null);
+        var nullOption2 = Option<MyOtherClass?>.Some(null);
+		nullOption.GetHashCode().Should().NotBe(nullOption2.GetHashCode());
+        nullOption.Equals(Option<MyClass?>.Some(new())).Should().BeFalse();
+        // ReSharper disable once SuspiciousTypeConversion.Global
+        nullOption.Equals(nullOption2).Should().BeFalse();
+        nullOption.Equals(Option<MyClass?>.Some(null)).Should().BeTrue();
+    }
+
+    class MyClass;
+
+    class MyOtherClass;
 }