Allow IEqualityComparer in string equality assertion #2339
Description
Background and motivation
I'm trying to assert two strings are equal using a custom comparer. The code below works, though it would be nice if the cast to object wouldn't be necessary and Be() could be used instead of BeEquivalentTo().
using System.Text.RegularExpressions;
using FluentAssertions;
string logLines = @"one\ntwo\nthree";
string expected = @"one\r\ntwo\r\nthree";
((object)logLines).Should().BeEquivalentTo(expected, options => options.Using(IgnoreLineEndingsComparer.Instance));
public sealed class IgnoreLineEndingsComparer : IEqualityComparer<string>
{
public static readonly IgnoreLineEndingsComparer Instance = new();
public bool Equals(string x, string y)
{
if (x == y)
{
return true;
}
if (x == null || y == null)
{
return false;
}
var xLines = Regex.Split(x, "\r\n|\r|\n");
var yLines = Regex.Split(x, "\r\n|\r|\n");
return xLines.SequenceEqual(yLines);
}
public int GetHashCode(string obj)
{
return obj.GetHashCode();
}
}API Proposal
public class StringAssertions<TAssertions> : ReferenceTypeAssertions<string, TAssertions>
where TAssertions : StringAssertions<TAssertions>
{
public AndConstraint<TAssertions> Be(string expected, IEqualityComparer<string> comparer,
string because = "", params object[] becauseArgs);
}API Usage
using System.Text.RegularExpressions;
using FluentAssertions;
string logLines = @"one\ntwo\nthree";
string expected = @"one\r\ntwo\r\nthree";
logLines.Should().Be(expected, IgnoreLineEndingsComparer.Instance);Alternative Designs
No response
Risks
No response
Are you willing to help with a proof-of-concept (as PR in that or a separate repo) first and as pull-request later on?
No