public void TestCreateByKey()
{
var comparer = EqualityComparers.Create((string s) => s.Length);
comparer.Equals("a", "b").ShouldEqual(true);
comparer.Equals(null, string.Empty).ShouldEqual(false);
comparer.Equals(string.Empty, null).ShouldEqual(false);
comparer.Equals("aa", "b").ShouldEqual(false);
comparer.GetHashCode("abc").ShouldEqual(3);
}
public void TestRapidExit()
{
var comparer = EqualityComparers.Create(
(int a, int b) => { throw new InvalidOperationException("should never get here"); },
i => { throw new InvalidOperationException("should never get here"); }
);
Sequence <int>().CollectionEquals(Sequence <int>(), comparer).ShouldEqual(true);
new int[0].CollectionEquals(new int[0], comparer).ShouldEqual(true);
new[] { 1, 2, 3 }.CollectionEquals(new[] { 1, 2, 3, 4 }).ShouldEqual(false);
}
public void TestComparerEquality()
{
Func <string, string, bool> sameLength = (a, b) => a.Length == b.Length;
Func <string, int> getLength = s => s.Length;
ComparersTest.TestEquality(EqualityComparers.Create(sameLength, getLength), EqualityComparers.Create(sameLength, getLength), EqualityComparers.Create(getLength));
ComparersTest.TestEquality(EqualityComparers.Create(getLength), EqualityComparers.Create(getLength, EqualityComparer <int> .Default), EqualityComparers.Create((string s) => s[0]));
ComparersTest.TestEquality(EqualityComparers.GetReferenceComparer <string>(), EqualityComparers.GetReferenceComparer <string>(), EqualityComparer <string> .Default);
ComparersTest.TestEquality(EqualityComparers.GetCollectionComparer(EqualityComparer <string> .Default), EqualityComparers.GetCollectionComparer <string>(), EqualityComparers.GetCollectionComparer(StringComparer.OrdinalIgnoreCase));
ComparersTest.TestEquality(EqualityComparers.GetSequenceComparer(StringComparer.Ordinal), EqualityComparers.GetSequenceComparer(StringComparer.Ordinal), EqualityComparers.GetCollectionComparer(StringComparer.Ordinal));
}
public void TestCreate()
{
Assert.Throws <ArgumentNullException>(() => EqualityComparers.Create <int>(null));
var comparer = EqualityComparers.Create <string>((a, b) => a.Length == b.Length);
comparer.Equals("a", "b").ShouldEqual(true);
comparer.Equals(null, string.Empty).ShouldEqual(false);
comparer.Equals(string.Empty, null).ShouldEqual(false);
comparer.Equals("aa", "b").ShouldEqual(false);
comparer.GetHashCode("abc").ShouldEqual(-1);
comparer = EqualityComparers.Create <string>((a, b) => a.Length == b.Length, s => s.Length);
comparer.Equals("a", "b").ShouldEqual(true);
comparer.Equals(null, string.Empty).ShouldEqual(false);
comparer.Equals(string.Empty, null).ShouldEqual(false);
comparer.Equals("aa", "b").ShouldEqual(false);
comparer.GetHashCode("abc").ShouldEqual(3);
}