Upgrade 3 to 4

This is a work in progress. Please send a PR with any amendments.

Also see the 4.0 milestone‚Äč

Func<string> customMessage removed

All overloads that accepted a Func<string> customMessage have been changed to string customMessage.

Diff tool functionality moved to DiffEngine

Diff tool functionality is now provided by DiffEngine.

The following APIs have been removed:

  • Shouldly.Configuration.DiffTool

  • ShouldlyConfiguration.DiffTools

  • Shouldly.Configuration.IShouldNotLaunchDiffTool

  • Shouldly.Configuration.DiffToolConfiguration

  • Shouldly.Configuration.KnownDiffTools

  • Shouldly.Configuration.KnownDoNotLaunchStrategies