From 2b920959fc653a7feb265c4d43378929007dd0e6 Mon Sep 17 00:00:00 2001
From: Pim Brouwers <pimnation@gmail.com>
Date: Sat, 7 Dec 2024 14:31:30 -0500
Subject: [PATCH] option icomparable

---
 .github/workflows/build.yml            |  2 +-
 src/Danom/Option/Option.cs             | 55 +++++++++++++++++++++++++-
 test/Danom.Tests/Option/OptionTests.cs | 24 +++++++++++
 3 files changed, 79 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index b147a6a..4911a12 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -20,7 +20,7 @@ jobs:
           dotnet-version: ${{ matrix.dotnet-version }}
 
       - name: Install solution dependencies
-        run: dotnet restore --force-evaluate --no-http-cache --force
+        run: dotnet restore src/Danom.Mvc --force-evaluate --no-http-cache --force
 
       - name: Build Core
         run: dotnet build src/Danom -c Release
diff --git a/src/Danom/Option/Option.cs b/src/Danom/Option/Option.cs
index c0172b2..f50124f 100644
--- a/src/Danom/Option/Option.cs
+++ b/src/Danom/Option/Option.cs
@@ -6,7 +6,7 @@ namespace Danom;
 /// </summary>
 /// <typeparam name="T"></typeparam>
 public readonly struct Option<T>
-    : IEquatable<Option<T>>
+    : IEquatable<Option<T>>, IComparable<Option<T>>
 {
     private readonly T? _some = default;
 
@@ -208,6 +208,42 @@ public static Task<Option<T>> NoneAsync() =>
     public static bool operator !=(Option<T> left, Option<T> right) =>
         !(left == right);
 
+    /// <summary>
+    /// Returns true if the specified <see cref="Option{T}"/> is less than the other.
+    /// </summary>
+    /// <param name="left"></param>
+    /// <param name="right"></param>
+    /// <returns></returns>
+    public static bool operator <(Option<T> left, Option<T> right) =>
+        left.CompareTo(right) < 0;
+
+    /// <summary>
+    /// Returns true if the specified <see cref="Option{T}"/> is less than or equal to the other.
+    /// </summary>
+    /// <param name="left"></param>
+    /// <param name="right"></param>
+    /// <returns></returns>
+    public static bool operator <=(Option<T> left, Option<T> right) =>
+        left.CompareTo(right) <= 0;
+
+    /// <summary>
+    /// Returns true if the specified <see cref="Option{T}"/> is greater than the other.
+    /// </summary>
+    /// <param name="left"></param>
+    /// <param name="right"></param>
+    /// <returns></returns>
+    public static bool operator >(Option<T> left, Option<T> right) =>
+        left.CompareTo(right) > 0;
+
+    /// <summary>
+    /// Returns true if the specified <see cref="Option{T}"/> is greater than or equal to the other.
+    /// </summary>
+    /// <param name="left"></param>
+    /// <param name="right"></param>
+    /// <returns></returns>
+    public static bool operator >=(Option<T> left, Option<T> right) =>
+        left.CompareTo(right) >= 0;
+
     /// <summary>
     /// Returns true if the specified <see cref="Option{T}"/>s are equal.
     /// </summary>
@@ -242,6 +278,23 @@ public override int GetHashCode() =>
             some: x => x is null ? 0 : x.GetHashCode(),
             none: () => 0);
 
+    /// <summary>
+    /// Compares the <see cref="Option{T}"/> to another <see cref="Option{T}"/>.
+    /// </summary>
+    /// <param name="other"></param>
+    /// <returns></returns>
+    public int CompareTo(Option<T> other) =>
+        Match(
+            some: x1 =>
+                other.Match(
+                    some: x2 => Comparer<T>.Default.Compare(x1, x2),
+                    none: () => 1),
+            none: () =>
+                other.Match(
+                    some: _ => -1,
+                    none: () => 0)
+            );
+
     /// <summary>
     /// Returns the string representation of the <see cref="Option{T}"/>.
     /// </summary>
diff --git a/test/Danom.Tests/Option/OptionTests.cs b/test/Danom.Tests/Option/OptionTests.cs
index ac7580c..54e5eb8 100644
--- a/test/Danom.Tests/Option/OptionTests.cs
+++ b/test/Danom.Tests/Option/OptionTests.cs
@@ -205,4 +205,28 @@ public void ToStringDefaultOrFormat()
         Assert.NotEqual("0", Option<decimal>.Some(1.9878565765675M).ToString("0", "C2"));
         Assert.Equal("£1.99", Option<decimal>.Some(1.9878565765675M).ToString("0", "C2", CultureInfo.CreateSpecificCulture("en-GB")));
     }
+
+#pragma warning disable CS1718 // Comparison made to same variable
+    [Fact]
+    public void Comparability()
+    {
+        var some1 = Option<int>.Some(1);
+        var some2 = Option<int>.Some(2);
+        var none = Option<int>.None();
+
+        Assert.True(some1 < some2);
+        Assert.True(some1 <= some2);
+        Assert.True(some2 > some1);
+        Assert.True(some2 >= some1);
+        Assert.True(some1 <= some1);
+        Assert.True(some1 >= some1);
+
+        Assert.True(none < some1);
+        Assert.True(none <= some1);
+        Assert.True(some1 > none);
+        Assert.True(some1 >= none);
+        Assert.True(none <= none);
+        Assert.True(none >= none);
+    }
 }
+#pragma warning restore CS1718 // Comparison made to same variable