array mutations are not reactive in a custom lightning-datatable component.

[vignesh191]

Description

When using a custom type lightning-datatable, methods such as push, pop, and splice on the data array are not reactive and do not cause a re-render on the custom type datatable element.

Steps to Reproduce

An example of a custom type lightning-datatable is described in these developer docs

As described in the above linked docs, a custom type datatable consists of the following layers:

• wrapper element (columns and data are defined here)

  • custom-type-datatable element (extends LightningDatatable and declares static customTypes)

  When doing an array mutation method on the data in the wrapper layer, the data attribute is not reactive, even when using @track.

LWC version: 6.5.3

[nolanlawson]

Thanks for filing! Do you have a repro you can share, e.g. using https://playground.lwc.dev?

I tried to write a minimal repro, but my repro seems to be working as documented. If I use @track and @api, then I can use push/pop/splice and the rendered output is updated.