FastObservableDictionary should allow null-values and not throw ArgumentNullException

[xaevik]

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• WPF
• UWP
• iOS
• Android
• .NET Standard
• .NET Core

Component

Catel.Collections.FastObservableDictionary

Version of Library

5.12.10

Version of OS(s) listed above with issue

Windows 10 20H2

Steps to Reproduce

1. Create a new FastObservableDictionary<> collection that supports nullable values (e.g. string)
2. Attempt to add an item to the collection with a null value (e.g. dict.Add("key1", null);)

Expected Behavior

The item key1 with a value of null should add to the collection

Actual Behavior

The exception ArgumentNullException is thrown because newValue is null. The behavior of FastObservableDictionary should follow the pattern of all derivatives of Dictionary in that only the key is not allowed to be null. It should be up to the caller/implementer to restrict that behavior.

I unfortunately do not have the bandwidth to absorb this right now.

[GeertvanHorrik]

Thanks for reporting. I will try to fix this in 6.0 and if we create a new hotfix, this will be included as well.

[GeertvanHorrik]

We are probably going to create a hotfix for #1712 , so will include this.

[GeertvanHorrik]

Adding unit tests.

[GeertvanHorrik]

done.