Activity invocation with duplicate function names is silently redirected to aliased registration

[antmendoza]

Expected Behavior

The workflow should invoke the activity registered with the requested name, not an aliased activity with the same underlying function name.

The worker registers two activities that have the same function name but different package implementations: one without an alias and one with an alias.

w.RegisterActivity(acvitity_v1.Activity)
w.RegisterActivityWithOptions(
    acvitity_v2.Activity,
    activity.RegisterOptions{
       Name: "Activity_v2",
    },
)

The workflow invokes the non-aliased activity either by name or by function:

err := workflow.ExecuteActivity(ctx, "Activity", name).Get(ctx, &result) or
err := workflow.ExecuteActivity(ctx, acvitity_v1.Activity, name).Get(ctx, &result)

However, the workflow ends up invoking activity_v2.Activity.

I think the issue is that the function getActivityFunctionName finds an alias registered for the given function name and resolves with the function attached to the alias

Actual Behavior

The worker should invoke the activity registered under the requested name, rather than silently resolving the invocation to an aliased activity with the same function name.

Steps to Reproduce the Problem

Attached you can find the reproduction

30967.zip

[amit-writes-code]

I think I can pick this one

[dplyukhin]

Thanks for the report! Unfortunately this is what happens when tasks have aliases and DisableRegistrationAliasing is disabled. The docs recommend you turn the flag on, but it's easy to miss and the docs don't warn about the problem you're running into.

We could turn DisableRegistrationAliasing on by default, but it would be a breaking change - I'll talk to the team. The least we could do is improve the docs and emit a warning when these collisions happen.

@amit-writes-code welcome and thanks for the PR! I don't think it addresses the underlying issue, which is that "aliases + DisableRegistrationAliasing disabled = sad times". But I'll double check.

[dplyukhin]

Btw in case it wasn't clear from my response, the solution to your problem is:

1. Set the following worker options:

	w := worker.New(c, "hello-world", worker.Options{
		DisableRegistrationAliasing: true,
	})

2. When using aliases, avoid invoking activities or workflows using function pointers. All three of the following lines are actually equivalent, which you might not expect:

	err := workflow.ExecuteActivity(ctx, activities_v1.Activity, name).Get(ctx, &result)
	err := workflow.ExecuteActivity(ctx, activities_v2.Activity, name).Get(ctx, &result)
	err := workflow.ExecuteActivity(ctx, "Activity", name).Get(ctx, &result)

[amit-writes-code]

I completely agree with the collision concern raised in #2384. #2385 actually aims to solve that exact problem by using fully qualified names in the map to prevent conflicts (e.g., shifting from map[Activity] = Fn to map[activities_v1.Activity] = Fn)

[dplyukhin]

Small update: this is a frequent enough problem that I'm working on an overhaul of the Go SDK workflow/activity registration semantics to avoid this type of problem. The tricky part is making sure the solution doesn't break existing workflows. Hope to address this soon :)