PatchOperation.Set cannot handle null values

[loraderon]

We are continuously addressing and improving the SDK, if possible, make sure the problem persist in the latest SDK version.

Describe the bug
PatchOperation.Set throws ArgumentNullException when value is null.

To Reproduce
await container.PatchItemAsync(id, PartitionKey.None, new List { PatchOperation.Set("/name", null) });

Expected behavior
Value should be set to null.

Actual behavior

System.ArgumentNullException: Value cannot be null. (Parameter 'value')
at Microsoft.Azure.Cosmos.PatchOperationCore`1..ctor(PatchOperationType operationType, String path, T value)
at Microsoft.Azure.Cosmos.PatchOperation.Set[T](String path, T value)

Environment summary
SDK Version: 3.23.0
OS Version (e.g. Windows, Linux, MacOSX) Windows 11

Additional context
According to @sajeetharan (https://stackoverflow.com/a/70194090/22092), this seems to be a known issue but I couldn't find any matching issue in github.

[yang-er]

Hi, I have a workaround as below which could resolve your problem:

await container.PatchItemAsync(id, PartitionKey.None, new List { PatchOperation.Set("/name", new MemoryStream(Encoding.UTF8.GetBytes("null"))) });

My thought is that here we shouldn't add null checks for value.

[Jezternz]

This sounds like it should work, but it appears that to make this workaround work as expected, modifications to json serialization would somehow have to happen:

[ghost]

This works for me.

Instead of using null I just create a JProperty with the value null. And use that value.

private JToken NullValue { get { return new JProperty("nullValue", null).Value; } }
And use it like this
operations.Add(PatchOperation.Set("\customer", value ?? NullValue));

[Jezternz]

Edit: Thanks @rvdvelden, that works perfectly!

[yang-er]

BTW, a much easier way to get a null JToken: JValue.CreateNull()

[kirankumarkolli]

@deparash what's the expected server contract for such scenarios?

[kirankumarkolli]

Update: (offline closure with @deparash )

Value is expected and it should be JSON NULL.
Current implementation is using JSON.NET for writing and it can leverage WriteNull() instead.

[kirankumarkolli]

@SchintaMicrosoft assigned it to you.

[onionhammer]

This should still be open, not closed. There are hacky workarounds for now, commented above

[j82w]

Github automatically closes the issue when the PR is merged. A new version should be released hopefully by tomorrow with the fix.

[onionhammer]

Not fixed in 3.26.2

[j82w]

Sorry about the confusion. The fix is going out in 3.27.0 which can be tracked here: #3172
The 3.27 release is waiting on this fix: #3168
3.26.2 is a hotfix to unblock a customer hitting an issue in production which is why it only has 3 required changes cherry picked.

[j82w]

@onionhammer please try the latest SDK release 3.27.0 https://github.com/Azure/azure-cosmos-dotnet-v3/releases/tag/3.27.0

[onionhammer]

Yep, thanks, that fixes it

[gagwithgaffer]

Using Microsoft.Azure.Cosmos 3.28 and i dont see any fix? will have to resort to the above said workaround from rvdvelden