Which package(s) are affected?

Lit Core (lit / lit-html / lit-element / reactive-element)

Description

When a standard private field is decorated with @state() the name of the field is something like '#foo', which requestUpdate() then uses to get the current value of the field, here:

this['#foo'] does not return the value of this.#foo, it is an entirely different property, so the change detection logic fails, specifically when changing value from undefined (since the new value will appear to be undefined and so no change is detected.

A fix would be to allow requestUpdate() to take the new value as a parameter instead of looking it up by name.

Reproduction

None yet. The playground doesn't support standard accessors yet.

Workaround

Use non-standard TypeScript private fields.

Is this a regression?

No or unsure. This never worked, or I haven't tried before.

Affected versions

3.x

Browser/OS/Node environment

All