From b34ea7b9c3af497f655103947a4887dca8218f53 Mon Sep 17 00:00:00 2001
From: Simon Lang <simon.lang@argusdatainsights.ch>
Date: Thu, 22 Feb 2024 13:54:17 +0100
Subject: [PATCH] Added Task and ValueTask versions for AsMaybe

---
 .../CSharpFunctionalExtensions.Tests.csproj   |  6 +++
 .../Extensions/AsMaybeTests.Task.cs           | 41 ++++++++++++++++++
 .../Extensions/AsMaybeTests.ValueTask.cs      | 42 +++++++++++++++++++
 .../MaybeTests/Extensions/AsMaybeTests.cs     | 10 ++---
 .../CSharpFunctionalExtensions.csproj         |  8 +++-
 .../Maybe/Extensions/AsMaybe.Task.cs          | 33 +++++++++++++++
 .../Maybe/Extensions/AsMaybe.ValueTask.cs     | 35 ++++++++++++++++
 7 files changed, 169 insertions(+), 6 deletions(-)
 create mode 100644 CSharpFunctionalExtensions.Tests/MaybeTests/Extensions/AsMaybeTests.Task.cs
 create mode 100644 CSharpFunctionalExtensions.Tests/MaybeTests/Extensions/AsMaybeTests.ValueTask.cs
 create mode 100644 CSharpFunctionalExtensions/Maybe/Extensions/AsMaybe.Task.cs
 create mode 100644 CSharpFunctionalExtensions/Maybe/Extensions/AsMaybe.ValueTask.cs

diff --git a/CSharpFunctionalExtensions.Tests/CSharpFunctionalExtensions.Tests.csproj b/CSharpFunctionalExtensions.Tests/CSharpFunctionalExtensions.Tests.csproj
index 2728130d..6669b138 100644
--- a/CSharpFunctionalExtensions.Tests/CSharpFunctionalExtensions.Tests.csproj
+++ b/CSharpFunctionalExtensions.Tests/CSharpFunctionalExtensions.Tests.csproj
@@ -397,6 +397,12 @@
     <Compile Update="ResultTests\Extensions\MatchTests.ValueTask.cs">
       <DependentUpon>MatchTests.cs</DependentUpon>
     </Compile>
+    <Compile Update="MaybeTests\Extensions\AsMaybeTests.Task.cs">
+      <DependentUpon>AsMaybeTests.cs</DependentUpon>
+    </Compile>
+    <Compile Update="MaybeTests\Extensions\AsMaybeTests.ValueTask.cs">
+      <DependentUpon>AsMaybeTests.cs</DependentUpon>
+    </Compile>
     <Compile Update="MaybeTests\Extensions\BindTests.Task.Right.cs">
       <DependentUpon>BindTests.Task.cs</DependentUpon>
     </Compile>
diff --git a/CSharpFunctionalExtensions.Tests/MaybeTests/Extensions/AsMaybeTests.Task.cs b/CSharpFunctionalExtensions.Tests/MaybeTests/Extensions/AsMaybeTests.Task.cs
new file mode 100644
index 00000000..99d9124b
--- /dev/null
+++ b/CSharpFunctionalExtensions.Tests/MaybeTests/Extensions/AsMaybeTests.Task.cs
@@ -0,0 +1,41 @@
+using System.Threading.Tasks;
+using CSharpFunctionalExtensions.Tests.ResultTests;
+using FluentAssertions;
+using Xunit;
+
+namespace CSharpFunctionalExtensions.Tests.MaybeTests.Extensions;
+
+public class AsMaybeTests_Task : TestBase
+{
+    [Fact]
+    public async Task AsMaybe_Task_Struct_maybe_conversion_equality_none()
+    {
+        double? none = default;
+        var maybeNone = await none.AsTask().AsMaybe();
+        maybeNone.HasValue.Should().Be(none.HasValue);
+    }
+
+    [Fact]
+    public async Task AsMaybe_Task_Struct_maybe_conversion_equality_some()
+    {
+        double? some = 123;
+        var someMaybe = await some.AsTask().AsMaybe();
+        someMaybe.HasValue.Should().Be(some.HasValue);
+        someMaybe.Value.Should().Be(some);
+    }
+
+    [Fact]
+    public async Task AsMaybe_Task_Class_maybe_conversion_none()
+    {
+        var maybeT = await Maybe<T>.None.AsTask();
+        maybeT.HasValue.Should().BeFalse();
+    }
+
+    [Fact]
+    public async Task AsMaybe_Task_Class_maybe_conversion_some()
+    {
+        var maybeT = await T.Value.AsMaybe().AsTask();
+        maybeT.HasValue.Should().BeTrue();
+        maybeT.Value.Should().Be(T.Value);
+    }
+}
diff --git a/CSharpFunctionalExtensions.Tests/MaybeTests/Extensions/AsMaybeTests.ValueTask.cs b/CSharpFunctionalExtensions.Tests/MaybeTests/Extensions/AsMaybeTests.ValueTask.cs
new file mode 100644
index 00000000..5b6161cf
--- /dev/null
+++ b/CSharpFunctionalExtensions.Tests/MaybeTests/Extensions/AsMaybeTests.ValueTask.cs
@@ -0,0 +1,42 @@
+using System.Threading.Tasks;
+using CSharpFunctionalExtensions.Tests.ResultTests;
+using CSharpFunctionalExtensions.ValueTasks;
+using FluentAssertions;
+using Xunit;
+
+namespace CSharpFunctionalExtensions.Tests.MaybeTests.Extensions;
+
+public class AsMaybeTests_ValueTask : TestBase
+{
+    [Fact]
+    public async Task AsMaybe_ValueTask_Struct_maybe_conversion_equality_none()
+    {
+        double? none = default;
+        var maybeNone = await none.AsValueTask().AsMaybe();
+        maybeNone.HasValue.Should().Be(none.HasValue);
+    }
+
+    [Fact]
+    public async Task AsMaybe_ValueTask_Struct_maybe_conversion_equality_some()
+    {
+        double? some = 123;
+        var someMaybe = await some.AsValueTask().AsMaybe();
+        someMaybe.HasValue.Should().Be(some.HasValue);
+        someMaybe.Value.Should().Be(some);
+    }
+
+    [Fact]
+    public async Task AsMaybe_ValueTask_Class_maybe_conversion_none()
+    {
+        var maybeT = await Maybe<T>.None.AsValueTask();
+        maybeT.HasValue.Should().BeFalse();
+    }
+
+    [Fact]
+    public async Task AsMaybe_ValueTask_Class_maybe_conversion_some()
+    {
+        var maybeT = await T.Value.AsValueTask().AsMaybe();
+        maybeT.HasValue.Should().BeTrue();
+        maybeT.Value.Should().Be(T.Value);
+    }
+}
diff --git a/CSharpFunctionalExtensions.Tests/MaybeTests/Extensions/AsMaybeTests.cs b/CSharpFunctionalExtensions.Tests/MaybeTests/Extensions/AsMaybeTests.cs
index 18d20f46..1088149c 100644
--- a/CSharpFunctionalExtensions.Tests/MaybeTests/Extensions/AsMaybeTests.cs
+++ b/CSharpFunctionalExtensions.Tests/MaybeTests/Extensions/AsMaybeTests.cs
@@ -7,7 +7,7 @@ namespace CSharpFunctionalExtensions.Tests.MaybeTests.Extensions;
 public class AsMaybeTests : TestBase
 {
     [Fact]
-    public void Struct_maybe_conversion_equality_none()
+    public void AsMaybe_Struct_maybe_conversion_equality_none()
     {
         double? none = default;
         Maybe<double> maybeNone = none.AsMaybe();
@@ -15,7 +15,7 @@ public void Struct_maybe_conversion_equality_none()
     }
 
     [Fact]
-    public void Struct_maybe_conversion_equality_some()
+    public void AsMaybe_Struct_maybe_conversion_equality_some()
     {
         double? some = 123;
         Maybe<double> someMaybe = some.AsMaybe();
@@ -24,17 +24,17 @@ public void Struct_maybe_conversion_equality_some()
     }
 
     [Fact]
-    public void Class_maybe_conversion_none()
+    public void AsMaybe_Class_maybe_conversion_none()
     {
         Maybe<T> maybeT = null;
         maybeT.HasValue.Should().BeFalse();
     }
 
     [Fact]
-    public void Class_maybe_conversion_some()
+    public void AsMaybe_Class_maybe_conversion_some()
     {
         Maybe<T> maybeT = T.Value.AsMaybe();
         maybeT.HasValue.Should().BeTrue();
         maybeT.Value.Should().Be(T.Value);
     }
-}
\ No newline at end of file
+}
diff --git a/CSharpFunctionalExtensions/CSharpFunctionalExtensions.csproj b/CSharpFunctionalExtensions/CSharpFunctionalExtensions.csproj
index 93a0b638..89f2249b 100644
--- a/CSharpFunctionalExtensions/CSharpFunctionalExtensions.csproj
+++ b/CSharpFunctionalExtensions/CSharpFunctionalExtensions.csproj
@@ -118,7 +118,13 @@
       <DependentUpon>GetValueOrDefault.cs</DependentUpon>
     </Compile>
     <Compile Update="Maybe\Extensions\Map.Task.cs">
-      <DependentUpon>Map.cs</DependentUpon>
+	    <DependentUpon>Map.cs</DependentUpon>
+    </Compile>
+    <Compile Update="Maybe\Extensions\AsMaybe.Task.cs">
+	    <DependentUpon>AsMaybe.cs</DependentUpon>
+    </Compile>
+    <Compile Update="Maybe\Extensions\AsMaybe.ValueTask.cs">
+	    <DependentUpon>AsMaybe.cs</DependentUpon>
     </Compile>
     <Compile Update="Result\Methods\Extensions\MapIf.Task.cs">
       <DependentUpon>MapIf.cs</DependentUpon>
diff --git a/CSharpFunctionalExtensions/Maybe/Extensions/AsMaybe.Task.cs b/CSharpFunctionalExtensions/Maybe/Extensions/AsMaybe.Task.cs
new file mode 100644
index 00000000..a845df12
--- /dev/null
+++ b/CSharpFunctionalExtensions/Maybe/Extensions/AsMaybe.Task.cs
@@ -0,0 +1,33 @@
+using System;
+using System.Threading.Tasks;
+
+namespace CSharpFunctionalExtensions
+{
+    public static partial class MaybeExtensions
+    {
+        // ReSharper disable ConvertNullableToShortForm
+        /// <summary>
+        /// Converts the <see cref="Nullable"/> struct to a <see cref="Maybe{T}"/>.
+        /// </summary>
+        /// <returns>Returns the <see cref="Maybe{T}"/> equivalent to the <see cref="Nullable{T}"/>.</returns>
+        public static async Task<Maybe<T>> AsMaybe<T>(this Task<Nullable<T>> nullableTask)
+            where T : struct
+        {
+            var nullable = await nullableTask.DefaultAwait();
+            return nullable.AsMaybe();
+        }
+
+#nullable enable
+        /// <summary>
+        /// Wraps the class instance in a <see cref="Maybe{T}"/>.
+        /// </summary>
+        /// <returns>Returns <see cref="Maybe.None"/> if the class instance is null, otherwise returns <see cref="Maybe.From{T}(T)"/>.</returns>
+        public static async Task<Maybe<T>> AsMaybe<T>(this Task<T?> nullableTask)
+            where T : class
+        {
+            var nullable = await nullableTask.DefaultAwait();
+            return nullable.AsMaybe();
+        }
+#nullable restore
+    }
+}
diff --git a/CSharpFunctionalExtensions/Maybe/Extensions/AsMaybe.ValueTask.cs b/CSharpFunctionalExtensions/Maybe/Extensions/AsMaybe.ValueTask.cs
new file mode 100644
index 00000000..30690881
--- /dev/null
+++ b/CSharpFunctionalExtensions/Maybe/Extensions/AsMaybe.ValueTask.cs
@@ -0,0 +1,35 @@
+#if NET5_0_OR_GREATER
+using System;
+using System.Threading.Tasks;
+
+namespace CSharpFunctionalExtensions.ValueTasks
+{
+    public static partial class MaybeExtensions
+    {
+        // ReSharper disable ConvertNullableToShortForm
+        /// <summary>
+        /// Converts the <see cref="Nullable"/> struct to a <see cref="Maybe{T}"/>.
+        /// </summary>
+        /// <returns>Returns the <see cref="Maybe{T}"/> equivalent to the <see cref="Nullable{T}"/>.</returns>
+        public static async ValueTask<Maybe<T>> AsMaybe<T>(this ValueTask<Nullable<T>> nullableTask)
+            where T : struct
+        {
+            var nullable = await nullableTask;
+            return nullable.AsMaybe();
+        }
+
+#nullable enable
+        /// <summary>
+        /// Wraps the class instance in a <see cref="Maybe{T}"/>.
+        /// </summary>
+        /// <returns>Returns <see cref="Maybe.None"/> if the class instance is null, otherwise returns <see cref="Maybe.From{T}(T)"/>.</returns>
+        public static async ValueTask<Maybe<T>> AsMaybe<T>(this ValueTask<T?> nullableTask)
+            where T : class
+        {
+            var nullable = await nullableTask;
+            return nullable.AsMaybe();
+        }
+#nullable restore
+    }
+}
+#endif