/// <summary>
/// Gets the maximum value in <paramref name="_this"/>.
/// </summary>
/// <typeparam name="T">The type of the objects to compare.</typeparam>
/// <param name="_this">The <see cref="IEnumerable{T}"/> that is used.</param>
/// <param name="comparer">The <see cref="IComparer"/> used for comparison.</param>
/// <returns>The maximum value in <paramref name="_this"/>.</returns>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="_this"/> is null.</exception>
/// <exception cref="ArgumentException">Thrown if <paramref name="_this"/> is empty.</exception>
/// <exception cref="ArgumentException">Thrown if <paramref name="_this"/> contains null values only.</exception>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="comparer"/> is null.</exception>
/// <example>
/// <code>
/// var min = myEnumeration.Max(new MyComparer());
/// </code>
/// </example>
public static T Maximum <T>(this IEnumerable <T> _this, IComparer comparer)
{
Throw.If.Object.IsNull(_this, nameof(_this));
Throw.If.Object.IsNull(comparer, nameof(comparer));
return(_this.Maximum(DynamicComparer.FromComparer <T>(comparer)));
}
void FromIComparable()
{
IComparer comp = null;
Int32 result = 0;
Test.IfNot.Action.ThrowsException(() => comp = DynamicComparer.FromIComparable <ExDummyIComparable>(), out Exception ex);
Test.IfNot.Action.ThrowsException(() => result = comp.Compare(null, null), out ArithmeticException ex2);
Test.If.Value.IsEqual(result, 0);
Test.IfNot.Action.ThrowsException(() => result = comp.Compare(null, (ExDummyIComparableT)0), out ex2);
Test.If.Value.IsEqual(result, 0);
Test.IfNot.Action.ThrowsException(() => result = comp.Compare((ExDummyIComparableT)0, null), out ex2);
Test.If.Value.IsEqual(result, 0);
Test.IfNot.Action.ThrowsException(() => result = comp.Compare((ExDummyIComparableT)0, (ExDummyIComparableT)1), out ex2);
Test.If.Value.IsEqual(result, 0);
Test.IfNot.Action.ThrowsException(() => result = comp.Compare(null, (ExDummyIComparable)0), out ex2);
Test.If.Value.IsEqual(result, -1);
Test.IfNot.Action.ThrowsException(() => result = comp.Compare((ExDummyIComparable)0, null), out ex2);
Test.If.Value.IsEqual(result, 1);
Test.If.Action.ThrowsException(() => result = comp.Compare((ExDummyIComparable)0, (ExDummyIComparable)1), out ex2);
Test.If.Value.IsEqual(ex2.Message, "'1'");
}
/// <summary>
/// Gets the minimum value in <paramref name="_this"/>.
/// </summary>
/// <typeparam name="T">The type of the objects to compare.</typeparam>
/// <param name="_this">The <see cref="IEnumerable{T}"/> that is used.</param>
/// <param name="comparer">The <see cref="IComparer"/> used for comparison.</param>
/// <returns>The minimum value in <paramref name="_this"/>.</returns>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="_this"/> is null.</exception>
/// <exception cref="ArgumentException">Thrown if <paramref name="_this"/> is empty.</exception>
/// <exception cref="ArgumentException">Thrown if <paramref name="_this"/> contains null values only.</exception>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="comparer"/> is null.</exception>
/// <example>
/// <code>
/// var min = myEnumeration.Min(new MyComparer());
/// </code>
/// </example>
public static T Minimum <T>(this IEnumerable <T> _this, IComparer comparer)
{
Throw.If.Object.IsNull(_this, nameof(_this));
Throw.If.Value.IsFalse(_this.Count() > 0, nameof(_this), "The enumeration is empty.");
Throw.If.Value.IsFalse(_this.Any((element) => element != null), nameof(_this), "The enumeration only contains null values.");
Throw.If.Object.IsNull(comparer, nameof(comparer));
return(_this.Minimum(DynamicComparer.FromComparer <T>(comparer)));
}
void FromDelegate()
{
IComparer comp = null;
Test.If.Action.ThrowsException(() => comp = DynamicComparer.FromDelegate(null), out ArgumentNullException ex1);
Test.If.Value.IsEqual(ex1.ParamName, "compare");
Test.IfNot.Action.ThrowsException(() => comp = DynamicComparer.FromDelegate((x, y) => 21), out Exception ex2);
}
void ComparisonInvokes()
{
IComparer comp = null;
Int32 result = 0;
comp = DynamicComparer.FromDelegate((x, y) => throw new NotImplementedException());
Test.If.Action.ThrowsException(() => result = comp.Compare(0, 1), out NotImplementedException ex1);
comp = DynamicComparer.FromDelegate((x, y) => 42);
Test.IfNot.Action.ThrowsException(() => result = comp.Compare(0, 1), out Exception ex2);
Test.If.Value.IsEqual(result, 42);
}
void FromComparer()
{
IComparer <Dummy> comp = null;
Int32 result = 0;
Test.If.Action.ThrowsException(() => comp = DynamicComparer.FromComparer <Dummy>(null), out ArgumentNullException ex1);
Test.If.Value.IsEqual(ex1.ParamName, "comparer");
Test.IfNot.Action.ThrowsException(() => comp = DynamicComparer.FromComparer <Dummy>(DynamicComparer.FromDelegate((x, y) => 42)), out Exception ex2);
result = comp.Compare(0, 1);
Test.If.Value.IsEqual(result, 42);
}
void MaxIComparerT_ThrowsException()
{
IEnumerable <Dummy> notEmpty = new Dummy[] { null, -1, -1, null, 0, 1, 1 };
IEnumerable <Dummy> empty = Enumerable.Empty <Dummy>();
IEnumerable <Dummy> nulls = new Dummy[] { null, null };
Test.If.Action.ThrowsException(() => IEnumerableTExtensions.Maximum(null, null as IComparer <Dummy>), out ArgumentNullException ex1);
Test.If.Value.IsEqual(ex1.ParamName, "_this");
Test.If.Action.ThrowsException(() => IEnumerableTExtensions.Maximum(null, DynamicComparer.FromDelegate <Dummy>((x, y) => 0)), out ex1);
Test.If.Value.IsEqual(ex1.ParamName, "_this");
Test.If.Action.ThrowsException(() => notEmpty.Maximum(null as IComparer <Dummy>), out ex1);
Test.If.Value.IsEqual(ex1.ParamName, "comparer");
Test.If.Action.ThrowsException(() => empty.Maximum(DynamicComparer.FromDelegate <Dummy>((x, y) => 0)), out ArgumentException ex2);
Test.If.Value.IsEqual(ex2.ParamName, "_this");
Test.If.String.StartsWith(ex2.Message, "The enumeration is empty.");
Test.If.Action.ThrowsException(() => nulls.Maximum(DynamicComparer.FromDelegate <Dummy>((x, y) => 0)), out ex2);
Test.If.Value.IsEqual(ex2.ParamName, "_this");
Test.If.String.StartsWith(ex2.Message, "The enumeration only contains null values.");
}