Split.String.Count.cs

using System;
using Xunit;

namespace PrimeFuncPack.Core.Tests;

using TestTheoryData = TheoryData<string?, string?, int, StringSplitOptions, string[]?, int>;

partial class FlatArrayExtensionsTest
{
    [Theory]
    [MemberData(nameof(SplitToFlatArray_WithStringSeparatorAndCount_ExpectCorrectState_Cases))]
    public void SplitToFlatArray_WithStringSeparatorAndCount_ExpectCorrectState(
        string? source, string? separator, int count, StringSplitOptions options, string[]? expectedItems, int expectedLength)
    {
        var actual = source.SplitToFlatArray(separator, count, options);
        actual.VerifyInnerState(expectedItems, expectedLength);
    }

    public static TestTheoryData SplitToFlatArray_WithStringSeparatorAndCount_ExpectCorrectState_Cases
        =>
        [
            new(null, ",", 1, StringSplitOptions.None, null, default),
            new("a,b,c", ",", -5, StringSplitOptions.None, null, default),
            new("a,b,c", ",", -1, StringSplitOptions.RemoveEmptyEntries, null, default),
            new(string.Empty, ",", 1, StringSplitOptions.None, [string.Empty], 1),
            new(string.Empty, ",", 1, StringSplitOptions.RemoveEmptyEntries, null, default),
            new("a,b,c", ",", 1, StringSplitOptions.None, ["a,b,c"], 1),
            new("a,b,c", ",", 2, StringSplitOptions.None, ["a", "b,c"], 2),
            new("a,b,c", ",", 3, StringSplitOptions.None, ["a", "b", "c"], 3),
            new("a,b,c", ",", 10, StringSplitOptions.None, ["a", "b", "c"], 3),
            new("a,,c", ",", 2, StringSplitOptions.None, ["a", ",c"], 2),
            new("a,,c", ",", 3, StringSplitOptions.RemoveEmptyEntries, ["a", "c"], 2),
            new(",a,b,", ",", 2, StringSplitOptions.None, ["", "a,b,"], 2),
            new(",a,b,", ",", 4, StringSplitOptions.RemoveEmptyEntries, ["a", "b"], 2),
            new("a||b||c", "||", 2, StringSplitOptions.None, ["a", "b||c"], 2),
            new("a||b||c", "||", 3, StringSplitOptions.None, ["a", "b", "c"], 3),
            new("a||||c", "||", 3, StringSplitOptions.None, ["a", "", "c"], 3),
            new("a||||c", "||", 3, StringSplitOptions.RemoveEmptyEntries, ["a", "c"], 2),
            new(" a :: b :: c ", "::", 3, StringSplitOptions.TrimEntries, ["a", "b", "c"], 3),
            new(" a ::  :: c ", "::", 3, StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries, ["a", "c"], 2),
            new("a b c", null, 2, StringSplitOptions.None, ["a b c"], 1),
            new("a b c", null, 3, StringSplitOptions.RemoveEmptyEntries, ["a b c"], 1),
            new("   ", null, 1, StringSplitOptions.None, ["   "], 1),
            new("   ", null, 4, StringSplitOptions.RemoveEmptyEntries, ["   "], 1),
            new("one", "x", 3, StringSplitOptions.None, ["one"], 1),
            new("xone", "x", 2, StringSplitOptions.RemoveEmptyEntries, ["one"], 1),
            new("a,b", ",", 0, StringSplitOptions.None, null, default),
            new("a b c", string.Empty, 2, StringSplitOptions.RemoveEmptyEntries, ["a b c"], 1)
        ];
}