// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the Apache 2.0 License.
// See the LICENSE file in the project root for more information. 

<#@ template debug="false" hostspecific="false" language="C#" #>
<#@ assembly name="System.Core" #>
<#@ import namespace="System.Linq" #>
<#@ import namespace="System.Text" #>
<#@ import namespace="System.Collections.Generic" #>
<#@ output extension=".cs" #>
<#
var types = new[] { typeof(int), typeof(long), typeof(float), typeof(double), typeof(decimal) };

Func<Type, string> toCSharp = t =>
{
    if (t == typeof(int))
        return "int";
    else if (t == typeof(long))
        return "long";
    else if (t == typeof(float))
        return "float";
    else if (t == typeof(double))
        return "double";
    else if (t == typeof(decimal))
        return "decimal";

    throw new Exception();
};
#>
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Xunit;

namespace Tests
{
    public class AverageAsync : AsyncEnumerableTests
    {
<#
foreach (var t in types)
{
    var cs = toCSharp(t);
#>
        [Fact]
        public async Task AverageAsync_<#=t.Name#>_Null()
        {
            await Assert.ThrowsAsync<ArgumentNullException>(() => AsyncEnumerable.AverageAsync(default(IAsyncEnumerable<<#=cs#>>)).AsTask());
        }

        [Fact]
        public async Task AverageAsync_<#=t.Name#>_Empty()
        {
            var ys = new <#=cs#>[0].ToAsyncEnumerable();
            await Assert.ThrowsAsync<InvalidOperationException>(() => ys.AverageAsync().AsTask());
        }

        [Fact]
        public async Task AverageAsync_<#=t.Name#>_Many()
        {
            var xs = new <#=cs#>[] { 2, 3, 5, 7, 11, 13, 17, 19 };
            var ys = xs.ToAsyncEnumerable();
            Assert.Equal(xs.Average(), await ys.AverageAsync());
        }

        [Fact]
        public async Task AverageAsync_Selector_<#=t.Name#>_Null()
        {
            await Assert.ThrowsAsync<ArgumentNullException>(() => AsyncEnumerable.AverageAsync(default(IAsyncEnumerable<<#=cs#>>), x => x).AsTask());
            await Assert.ThrowsAsync<ArgumentNullException>(() => AsyncEnumerable.AverageAsync(AsyncEnumerable.Empty<object>(), default(Func<object, <#=cs#>>)).AsTask());
        }

        [Fact]
        public async Task AverageAsync_Selector_<#=t.Name#>_Empty()
        {
            var ys = new <#=cs#>[0].ToAsyncEnumerable();
            await Assert.ThrowsAsync<InvalidOperationException>(() => ys.AverageAsync(x => x).AsTask());
        }

        [Fact]
        public async Task AverageAsync_Selector_<#=t.Name#>_Many()
        {
            var xs = new <#=cs#>[] { 2, 3, 5, 7, 11, 13, 17, 19 };
            var ys = xs.ToAsyncEnumerable();
            Assert.Equal(xs.Average(), await ys.AverageAsync(x => x));
        }

        [Fact]
        public async Task AverageAwaitAsync_Selector_<#=t.Name#>_Null()
        {
            await Assert.ThrowsAsync<ArgumentNullException>(() => AsyncEnumerable.AverageAwaitAsync(default(IAsyncEnumerable<<#=cs#>>), x => new ValueTask<<#=cs#>>(x)).AsTask());
            await Assert.ThrowsAsync<ArgumentNullException>(() => AsyncEnumerable.AverageAwaitAsync(AsyncEnumerable.Empty<object>(), default(Func<object, ValueTask<<#=cs#>>>)).AsTask());
        }

        [Fact]
        public async Task AverageAwaitAsync_Selector_<#=t.Name#>_Empty()
        {
            var ys = new <#=cs#>[0].ToAsyncEnumerable();
            await Assert.ThrowsAsync<InvalidOperationException>(() => ys.AverageAwaitAsync(x => new ValueTask<<#=cs#>>(x)).AsTask());
        }

        [Fact]
        public async Task AverageAwaitAsync_Selector_<#=t.Name#>_Many()
        {
            var xs = new <#=cs#>[] { 2, 3, 5, 7, 11, 13, 17, 19 };
            var ys = xs.ToAsyncEnumerable();
            Assert.Equal(xs.Average(), await ys.AverageAwaitAsync(x => new ValueTask<<#=cs#>>(x)));
        }

#if !NO_DEEP_CANCELLATION
        [Fact]
        public async Task AverageAwaitWithCancellationAsync_Selector_<#=t.Name#>_Null()
        {
            await Assert.ThrowsAsync<ArgumentNullException>(() => AsyncEnumerable.AverageAwaitWithCancellationAsync(default(IAsyncEnumerable<<#=cs#>>), (x, ct) => new ValueTask<<#=cs#>>(x)).AsTask());
            await Assert.ThrowsAsync<ArgumentNullException>(() => AsyncEnumerable.AverageAwaitWithCancellationAsync(AsyncEnumerable.Empty<object>(), default(Func<object, CancellationToken, ValueTask<<#=cs#>>>)).AsTask());
        }

        [Fact]
        public async Task AverageAwaitWithCancellationAsync_Selector_<#=t.Name#>_Empty()
        {
            var ys = new <#=cs#>[0].ToAsyncEnumerable();
            await Assert.ThrowsAsync<InvalidOperationException>(() => ys.AverageAwaitWithCancellationAsync((x, ct) => new ValueTask<<#=cs#>>(x), CancellationToken.None).AsTask());
        }

        [Fact]
        public async Task AverageAwaitWithCancellationAsync_Selector_<#=t.Name#>_Many()
        {
            var xs = new <#=cs#>[] { 2, 3, 5, 7, 11, 13, 17, 19 };
            var ys = xs.ToAsyncEnumerable();
            Assert.Equal(xs.Average(), await ys.AverageAwaitWithCancellationAsync((x, ct) => new ValueTask<<#=cs#>>(x), CancellationToken.None));
        }
#endif

        [Fact]
        public async Task AverageAsync_<#=t.Name#>_Nullable_Null()
        {
            await Assert.ThrowsAsync<ArgumentNullException>(() => AsyncEnumerable.AverageAsync(default(IAsyncEnumerable<<#=cs#>?>)).AsTask());
        }

        [Fact]
        public async Task AverageAsync_<#=t.Name#>_Nullable_Empty()
        {
            var ys = new <#=cs#>?[0].ToAsyncEnumerable();
            Assert.Null(await ys.AverageAsync());
        }

        [Fact]
        public async Task AverageAsync_<#=t.Name#>_Nullable_Many()
        {
            var xs = new <#=cs#>?[] { 2, 3, 5, 7, 11, 13, 17, 19 };
            var ys = xs.ToAsyncEnumerable();
            Assert.Equal(xs.Average(), await ys.AverageAsync());
        }

        [Fact]
        public async Task AverageAsync_Selector_<#=t.Name#>_Nullable_Empty()
        {
            var ys = new <#=cs#>?[0].ToAsyncEnumerable();
            Assert.Null(await ys.AverageAsync(x => x));
        }

        [Fact]
        public async Task AverageAsync_Selector_<#=t.Name#>_Nullable_Many()
        {
            var xs = new <#=cs#>?[] { 2, 3, 5, 7, 11, 13, 17, 19 };
            var ys = xs.ToAsyncEnumerable();
            Assert.Equal(xs.Average(), await ys.AverageAsync(x => x));
        }

        [Fact]
        public async Task AverageAwaitAsync_Selector_<#=t.Name#>_Nullable_Null()
        {
            await Assert.ThrowsAsync<ArgumentNullException>(() => AsyncEnumerable.AverageAwaitAsync(default(IAsyncEnumerable<<#=cs#>?>), x => new ValueTask<<#=cs#>?>(x)).AsTask());
            await Assert.ThrowsAsync<ArgumentNullException>(() => AsyncEnumerable.AverageAwaitAsync(AsyncEnumerable.Empty<object>(), default(Func<object, ValueTask<<#=cs#>?>>)).AsTask());
        }


        [Fact]
        public async Task AverageAwaitAsync_Selector_<#=t.Name#>_Nullable_Empty()
        {
            var ys = new <#=cs#>?[0].ToAsyncEnumerable();
            Assert.Null(await ys.AverageAwaitAsync(x => new ValueTask<<#=cs#>?>(x)));
        }

        [Fact]
        public async Task AverageAwaitAsync_Selector_<#=t.Name#>_Nullable_Many()
        {
            var xs = new <#=cs#>?[] { 2, 3, 5, 7, 11, 13, 17, 19 };
            var ys = xs.ToAsyncEnumerable();
            Assert.Equal(xs.Average(), await ys.AverageAwaitAsync(x => new ValueTask<<#=cs#>?>(x)));
        }

#if !NO_DEEP_CANCELLATION
        [Fact]
        public async Task AverageAwaitWithCancellationAsync_Selector_<#=t.Name#>_Nullable_Null()
        {
            await Assert.ThrowsAsync<ArgumentNullException>(() => AsyncEnumerable.AverageAwaitWithCancellationAsync(default(IAsyncEnumerable<<#=cs#>?>), (x, ct) => new ValueTask<<#=cs#>?>(x)).AsTask());
            await Assert.ThrowsAsync<ArgumentNullException>(() => AsyncEnumerable.AverageAwaitWithCancellationAsync(AsyncEnumerable.Empty<object>(), default(Func<object, CancellationToken, ValueTask<<#=cs#>?>>)).AsTask());
        }

        [Fact]
        public async Task AverageAwaitWithCancellationAsync_Selector_<#=t.Name#>_Nullable_Empty()
        {
            var ys = new <#=cs#>?[0].ToAsyncEnumerable();
            Assert.Null(await ys.AverageAwaitWithCancellationAsync((x, ct) => new ValueTask<<#=cs#>?>(x), CancellationToken.None));
        }

        [Fact]
        public async Task AverageAwaitWithCancellationAsync_Selector_<#=t.Name#>_Nullable_Many()
        {
            var xs = new <#=cs#>?[] { 2, 3, 5, 7, 11, 13, 17, 19 };
            var ys = xs.ToAsyncEnumerable();
            Assert.Equal(xs.Average(), await ys.AverageAwaitWithCancellationAsync((x, ct) => new ValueTask<<#=cs#>?>(x), CancellationToken.None));
        }
#endif

<#
}
#>
    }
}