T3012: Missing required contract field

Cause

A required contract field is missing (name, role and parts are required), or a pairing is missing its foreground or background.

Example

<contract>
{ "name": "Card", "role": "group" }
</contract>
<template><div class="root"></div></template>

What you see

ERROR  T3012  app/components/Card.tess:2:1
  Missing required field "parts".
  Run `tessera explain T3012` for details.

Fix

Add the field the message names.

All errors and warnings