duplicate of #11373

@edison1105 Are you sure this is a duplicate? I've looked through #11373, and also through #4866 (linked there), and both of these issues reference situations that use dynamically assigned template refs, i.e. code that uses :ref="x".

This is NOT what is going on here in my issue. I have a hardcoded reference to p in my code; perfectly statically analyzable. This issue has (at least by what I can tell) nothing to do with the "design flaw" Evan is referring to in the other two issues.

This issue is similar to the other two in the sense that it concerns template refs and dev/prod build differences, however the bug itself feels different. Maybe I'm wrong here and they are related; could you elaborate how this issue and the other two are caused by the same defect?

This here seems to be the code causing the divergence: (EDIT: It's not?)

I think it's destructuring owner from the rawRef here, which in my case (new A()) is obviously undefined. Thankfully in non-prod, the code catches this returns out of the function. However, in prod it continues and then runs into an error.

Is there a reason why it continues in production? Is there any scenario in which !owner is true and the code that follows it is still well-behaved?

Perhaps this is the intended code:

  if (!owner) {
    if (process.env.NODE_ENV !== "production") {
      warn$1(
        `Missing ref owner context. ref cannot be used on hoisted vnodes. A vnode with ref must be created inside the render function.`
      );
    }
    return;
  }

You can switch between DEV and PROD to inspect the compiled code.

At runtime

• in the DEV environment, set the ref value using setupState["refName"] = el.
• in the PROD environment, there is no setupState object, so the ref value is set using ref.value = el.
  However, const p = new A() is analyzed as setup-maybe-ref, but it is not a ref. This results in inconsistencies between DEV and PROD environments.
  While this inconsistency differs somewhat from Inconsistent behavior of template refs between development server and production builds #11373 and 项目编译后，component标签上ref属性对应的响应式对象为空，开发环境下正常 #4866, fundamentally, it is also a design flaw.

Developers should follow the documentation

• declare a ref to hold the element reference
• useTemplateRef

Looked at #12031 and I think the correct change should be detecting such usage during development (when setting the template ref, if the key exists on setupState but is not a ref) and emit a warning.