feature/random-extensions (#80)

* Added `Random.Next` that obtains a random element from a list of elements.

* Removed example code from playground.

Author: MrMatthewLayton

Directory.Build.props

@@ -1,7 +1,7 @@
 <Project>
     <PropertyGroup>
-        <Version>9.3.0</Version>
-        <PackageVersion>9.3.0</PackageVersion>
-        <AssemblyVersion>9.3.0</AssemblyVersion>
+        <Version>9.4.0</Version>
+        <PackageVersion>9.4.0</PackageVersion>
+        <AssemblyVersion>9.4.0</AssemblyVersion>
     </PropertyGroup>
 </Project>

OnixLabs.Core.UnitTests/RandomExtensionTests.cs

@@ -0,0 +1,36 @@
+// Copyright 2020 ONIXLabs
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System;
+using Xunit;
+
+namespace OnixLabs.Core.UnitTests;
+
+public sealed class RandomExtensionTests
+{
+    [Fact(DisplayName = "Random.Next should produce the expected result")]
+    public void RandomNextShouldProduceExpectedResult()
+    {
+        // Given
+        Random random = new(0);
+        const string expected = "klm";
+        string[] values = ["abc", "def", "hij", "klm", "xyz"];
+
+        // When
+        string actual = random.Next(values);
+
+        // Then
+        Assert.Equal(expected, actual);
+    }
+}

OnixLabs.Core/Extensions.Random.cs

@@ -0,0 +1,35 @@
+// Copyright 2020 ONIXLabs
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+
+namespace OnixLabs.Core;
+
+/// <summary>
+/// Provides extension methods for objects.
+/// </summary>
+[EditorBrowsable(EditorBrowsableState.Never)]
+public static class RandomExtensions
+{
+    /// <summary>
+    /// Obtains a random element from the specified <see cref="IReadOnlyList{T}"/> items.
+    /// </summary>
+    /// <param name="random">The current <see cref="Random"/> instance.</param>
+    /// <param name="items">The <see cref="IReadOnlyList{T}"/> items from which to obtain a random element.</param>
+    /// <typeparam name="T">The underlying type of the <see cref="IReadOnlyList{T}"/> collection.</typeparam>
+    /// <returns>Returns a random element from the specified <see cref="IReadOnlyList{T}"/> items.</returns>
+    public static T Next<T>(this Random random, IReadOnlyList<T> items) => items[random.Next(0, items.Count)];
+}