feat: add AsyncEnumerableFactory.FromSingleItem<T>

atc-net · Aug 15, 2024 · 616fdce · 616fdce
1 parent 06f05d0
commit 616fdce
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diff --git a/src/Atc/Factories/AsyncEnumerableFactory.cs b/src/Atc/Factories/AsyncEnumerableFactory.cs
@@ -15,4 +15,16 @@ public static async IAsyncEnumerable<T> Empty<T>()
         await Task.CompletedTask;
         yield break;
     }
+
+    /// <summary>
+    /// Converts a single item into an <see cref="IAsyncEnumerable{T}"/>.
+    /// </summary>
+    /// <typeparam name="T">The type of the item.</typeparam>
+    /// <param name="item">The item to convert.</param>
+    /// <returns>An <see cref="IAsyncEnumerable{T}"/> containing the single item.</returns>
+    public static async IAsyncEnumerable<T> FromSingleItem<T>(T item)
+    {
+        yield return item;
+        await Task.CompletedTask;
+    }
 }
diff --git a/test/Atc.Tests/Factories/AsyncEnumerableFactoryTests.cs b/test/Atc.Tests/Factories/AsyncEnumerableFactoryTests.cs
@@ -86,4 +86,67 @@ public async Task Empty_ReturnsEmptySequence_WithDifferentTypes()
         Assert.Empty(stringResult);
         Assert.Empty(customTypeResult);
     }
+
+    [Fact]
+    public async Task FromSingleItem_ReturnsAsyncEnumerableWithSingleItem()
+    {
+        // Arrange
+        const int item = 42;
+
+        // Act
+        var result = new List<int>();
+        await foreach (var value in AsyncEnumerableFactory.FromSingleItem(item))
+        {
+            result.Add(value);
+        }
+
+        // Assert
+        Assert.Single(result);
+        Assert.Equal(item, result.First());
+    }
+
+    [Fact]
+    public async Task FromSingleItem_ReturnsAsyncEnumerable_WithReferenceType()
+    {
+        // Arrange
+        const string item = "TestString";
+
+        // Act
+        var result = new List<string>();
+        await foreach (var value in AsyncEnumerableFactory.FromSingleItem(item))
+        {
+            result.Add(value);
+        }
+
+        // Assert
+        Assert.Single(result);
+        Assert.Equal(item, result.First());
+    }
+
+    [Fact]
+    public async Task FromSingleItem_CanBeEnumeratedMultipleTimes()
+    {
+        // Arrange
+        var item = 42;
+        var asyncEnumerable = AsyncEnumerableFactory.FromSingleItem(item);
+
+        // Act
+        var firstEnumeration = new List<int>();
+        await foreach (var value in asyncEnumerable)
+        {
+            firstEnumeration.Add(value);
+        }
+
+        var secondEnumeration = new List<int>();
+        await foreach (var value in asyncEnumerable)
+        {
+            secondEnumeration.Add(value);
+        }
+
+        // Assert
+        Assert.Single(firstEnumeration);
+        Assert.Single(secondEnumeration);
+        Assert.Equal(item, firstEnumeration.First());
+        Assert.Equal(item, secondEnumeration.First());
+    }
 }