Add ability to dynamically limit graph depth in `Formatter`

Add ability to limit graph depth in Formatter

Currently it is hardcoded to 5, which makes error messages for assertions on collections containing complex object graphs unreadable.

 private static string FormatChild(string path, object childValue, bool useLineBreaks, ObjectGraph graph) {
    /// ...
                else if (graph.Depth > 5)
                {
                    return "{Maximum recursion depth was reached…}";
                }
}

Would be nice to have an option to pass depth to collection assertion e.g.

result.Should().Contain(p => p.Foo == "Bar", maxDepth: 1);

Current behavior

For list of 2 complex objects, I’m getting message Expected result { ... containing almost 200 lines of text

Versions

• FluentAssertions: 5.10.2
• .NET Core 2.2.

[pgolinski]

Yes. It would be easy to configure for simple cases.

I must confess I used your workaround to cut off ILog from log4net 😉. Thank you.

private class LogFormatter : IValueFormatter
{
	public bool CanHandle(object value) => value is ILog;

	public string Format(object value, FormattingContext context, FormatChild formatChild)
		=> value.ToString();
}

[jnyrup]

How about adding a ConcurrentDictionary<Type, int> to Formatter to allow specifying the maxDepth per type?

private static ConcurrentDictionary<Type, int> MaxDepths { get; }

public static int MaxDepth { get; set; } = 5;

public static void SetMaxDepth<T>(int maxDepth) =>
    MaxDepths[typeof(T)] = maxDepth;

private static int GetMaxDepth(object obj) => 
    MaxDepths.TryGetValue(obj.GetType(), out int maxDepth)
    ? maxDepth
    : MaxDepth;

...
else if (graph.Depth > GetMaxDepth(childValue))