Add upsertMemo command

[lorensr]

Is your feature request related to a problem? Please describe.

User would like to edit memo from inside the Workflow, like upsertSearchAttributes

https://temporalio.slack.com/archives/C01DKSMU94L/p1659963126631549

Describe the solution you'd like

import { upsertMemo } from '@temporalio/workflow'

function myWorkflow() {
  upsertMemo({ newField: 'foo', changeExistingField: 'bar' })
}

SDKs

• Core - [Feature Request] Implement ModifyWorkflowProperties command sdk-core#383
• TS - [Feature Request] Add upsertMemo command sdk-typescript#1124
• Python - [Feature Request] Upsert memo support sdk-python#190
• Go - Add UpsertMemo API sdk-go#883
• Java - Upsert memo support sdk-java#623
• .NET - since inception
• PHP

[bergundy]

How would I delete an existing field?

[dnr]

Set it to null. We support this for search attributes now with temporalio/temporal#3047.

[bergundy]

Requires an sdk-features issue plus spec.
I'd like us to think what the behavior's going to be when we allow modifying the memo externally.
It could be as simple as "last writer wins" as long as the server is responsible for merging partial upserts IMHO, others have raise a need for an update token but I don't think that's necessary here.

[bergundy]

Set it to null. We support this for search attributes now with temporalio/temporal#3047.

We'd have to think if that's the desired experience per SDK, we might want a deleteMemoFields helper, we'll decide at implementation time.

[bergundy]

Moved to sdk-features

[bergundy]

From the Go PR, we should discuss the behavior in SDK:

Didn't look at the code but something I wish we'd done with search attributes in TS is delay sending the command until the end of an "activation", so if a user calls UpsertMemo({ a: 1 }); UpsertMemo({ b: 2 }); UpsertMemo({ a: 2 }) the SDK would only issue 1 UpsertMemo({ a: 2, b: 2}) command.