dotnet-sdk/test/Dapr.Actors.Generators.Test/Extensions/IEnumerableExtensionsTests.cs

using Dapr.Actors.Generators.Extensions;

namespace Dapr.Actors.Generators.Test.Extensions
{
    public class IEnumerableExtensionsTests
    {
        [Fact]
        public void IndexOf_WhenPredicateIsNull_ThrowsArgumentNullException()
        {
            // Arrange
            var source = new[] { 1, 2, 3, 4, 5 };
            Func<int, bool> predicate = null!;

            // Act
            Action act = () => source.IndexOf(predicate);

            // Assert
            Assert.Throws<ArgumentNullException>(act);
        }

        [Theory]
        [InlineData(new int[] { }, 3, -1)]
        [InlineData(new[] { 1, 2, 3, 4, 5 }, 6, -1)]
        public void IndexOf_WhenItemDoesNotExist_ReturnsMinusOne(int[] source, int item, int expected)
        {
            // Arrange
            Func<int, bool> predicate = (x) => x == item;

            // Act
            var index = source.IndexOf(predicate);

            // Assert
            Assert.Equal(expected, index);
        }

        [Theory]
        [InlineData(new[] { 1, 2, 3, 4, 5 }, 3, 2)]
        [InlineData(new[] { 1, 2, 3, 4, 5 }, 1, 0)]
        [InlineData(new[] { 1, 2, 3, 4, 5 }, 5, 4)]
        public void IndexOf_WhenItemExists_ReturnsIndexOfItem(int[] source, int item, int expected)
        {
            // Arrange
            Func<int, bool> predicate = (x) => x == item;

            // Act
            var index = source.IndexOf(predicate);

            // Assert
            Assert.Equal(expected, index);
        }
    }
}