// Copyright (c) Microsoft. All rights reserved.

// Licensed under the MIT license. See LICENSE file in the project root for full license information.

using System;

using System.Collections.Generic;

using Xunit;

namespace System.Linq.Tests

{

public class ContainsTests : EnumerableBasedTests

{

[Fact]

public void Empty()

{

int[] source = { };

Assert.False(source.AsQueryable().Contains(6));

}

[Fact]

public void NotPresent()

{

int[] source = { 8, 10, 3, 0, -8 };

Assert.False(source.AsQueryable().Contains(6));

}

[Fact]

public void MultipleMatches()

{

int[] source = { 8, 0, 10, 3, 0, -8, 0 };

Assert.True(source.AsQueryable().Contains(0));

}

[Fact]

public void DefaultComparerFromNull()

{

string[] source = { "Bob", "Robert", "Tim" };

Assert.False(source.AsQueryable().Contains("trboeR", null));

Assert.True(source.AsQueryable().Contains("Tim", null));

}

[Fact]

public void CustomComparerFromNull()

{

string[] source = { "Bob", "Robert", "Tim" };

Assert.True(source.AsQueryable().Contains("trboeR", new AnagramEqualityComparer()));

Assert.False(source.AsQueryable().Contains("nevar", new AnagramEqualityComparer()));

}

[Fact]

public void NullSource()

{

IQueryable<int> source = null;

Assert.Throws<ArgumentNullException>("source", () => source.Contains(42));

Assert.Throws<ArgumentNullException>("source", () => source.Contains(42, EqualityComparer<int>.Default));

}

[Fact]

public void Contains1()

{

var val = (new int[] { 0, 2, 1 }).AsQueryable().Contains(1);

Assert.True(val);

}

[Fact]

public void Contains2()

{

var val = (new int[] { 0, 2, 1 }).AsQueryable().Contains(1, EqualityComparer<int>.Default);

Assert.True(val);

}

}

}