Merge pull request #16 from Meerownymous/i14-add-conditional-w2arp

feat: conditional

WHyLL.sln

@@ -10,6 +10,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution
 		appveyor.yml = appveyor.yml
 		build.sh = build.sh
 		.github\workflows\ci-cd.yml = .github\workflows\ci-cd.yml
+		.gitignore = .gitignore
 	EndProjectSection
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WHyLL", "src\WHyLL\WHyLL.csproj", "{EAEA2EE1-691C-43B9-B171-8430D5ED6813}"

src/WHyLL/Warp/Conditional.cs

@@ -0,0 +1,29 @@
+namespace WHyLL.Warp;
+
+/// <summary>
+/// Warp depending on a condition.
+/// </summary>
+public sealed class Conditional<TOutcome>(
+    Func<IMessage, Task<bool>> condition,
+    IWarp<TOutcome> yes,
+    IWarp<TOutcome> no)
+    : WarpEnvelope<TOutcome>(
+        new MessageAs<TOutcome>(async msg =>
+            await condition(msg)
+                ? await msg.To(yes)
+                : await msg.To(no)
+        )
+    )
+{
+    /// <summary>
+    /// Warp depending on a condition.
+    /// </summary>
+    public Conditional(
+        Func<IMessage, bool> condition,
+        IWarp<TOutcome> yes,
+        IWarp<TOutcome> no
+    ) : this(message => Task.FromResult(condition(message)), 
+        yes, 
+        no
+    ){ }
+}

tests/Test.WHyLL/Warp/ConditionalTests.cs

@@ -0,0 +1,33 @@
+using WHyLL.Warp;
+using Xunit;
+
+namespace Test.WHyLL.Warp;
+
+public sealed class ConditionalTests
+{
+    [Fact]
+    public async Task DelegatesToYes()
+    {
+        Assert.Equal(100,
+            await 
+                new Conditional<int>(
+                    _ => true,
+                    new BodyAs<int>(_ => 100),
+                    new BodyAs<int>(_ => 0)
+                ).Render()
+        );
+    }
+
+    [Fact]
+    public async Task DelegatesToNo()
+    {
+        Assert.Equal(50,
+            await 
+                new Conditional<int>(
+                    _ => false,
+                    new BodyAs<int>(_ => 100),
+                    new BodyAs<int>(_ => 50)
+                ).Render()
+        );
+    }
+}