Workflow Update

[dandavison]

Fixes #1160

• Implement support for Workflow Update

API

To see examples using the new API, see

• Typescript Update features features#362
• packages/test/src/test-integration-update-*

Briefly:

// An Update is defined similarly to Query and Signal. The second type parameter (input) is optional
const myUpdate = wf.defineUpdate<string, [string]>('myUpdate');

// A handler is a sync or async function; the optional validator is always sync.
wf.setHandler(myUpdate, handler, { validator });

// `await wfHandle.executeUpdate` to start an update and block until it completes or fails.
// The signature resembles `WorkflowClient.start` in that the arguments are supplied
// in the optional options object
// (as opposed to the variadic signatures of wfHandle.query and wfHandle.signal)
// An error is thrown if the RPC times out (we do not poll for this call)
// or if the validator rejects, or the handler throws ApplicationFailure.
const updateResult = await handle.executeUpdate(myUpdate, { args: ['a'] });

// `startUpdate` to block until Accepted and obtain a handle to the Update. Signature the same as `executeUpdate`.
const updateHandle = await handle.startUpdate(myUpdate, { args: ['a'] });
// Blocking call to fetch result, with polling.
// Validation failures or ApplicationFailure in the handler would throw here.
const updateResult = await updateHandle.result();

How was this tested

• features tests Typescript Update features features#362
• packages/test/src/integration-tests/test-update*

Checklist

1. Closes [Typescript] Workflow update support #1160

2. Any docs updates needed?
   Yes

3. Not done in this PR:

   • Test that non-ApplicationFailure error in handler fails the task
   • Tests involving continue-as-new (e.g. providing coverage for firstExecutionRunId)
   • Support late registration
   • Fail task if workflow commands created during validation
   • Support setting a default update handler

[cretz]

May also want a TODO concerning supporting user-facing cancellation on long-poll/RPC-loop calls (AbortSignal I think was what was decided) and a link to the issue (or make one)

[bergundy]

You might want to have a type alias here to avoid this long statement.

[lorensr]

Yay! 💃

[bergundy]

I think we agreed to mark all of the update APIs experimental, please do so.

[bergundy]

Meant to comment before, accidentally approved.

[dandavison]

In addition to the tests here, this PR passes the features tests for TS in temporalio/features#362

[mjameswh]

nit: You could have combine all of those checks into a single "Misformed activation" error. Being very detailed is useful for user provided objects (ie. errors are more likely, are user need to know what they need to fix), but here, a missing field would indicate a server/core level error.

[mjameswh]

Please make sure to fix the four floating promises before you merge. Otherwise, just a suggestion, don't feel obliged.

Great job, thanks a lot!

[dandavison]

Thanks @mjameswh and @bergundy for all the reviewing here!