A simple WordPress block plugin with block.json viewModule

block.json

{
  "$schema": "https://schemas.wp.org/trunk/block.json",
  "apiVersion": 3,
  "title": "Jon's cool counter",
  "name": "jon/the-block",
  "editorScript": "file:./index.js",
  "viewModule": "file:./view.js",
  "render": "file:./render.php",
  "category": "text"
}

index.asset.php

<?php return array('dependencies' => array('react', 'wp-blocks'), 'version' => '04a7cb7df938528c50ee');

index.js

const e = window.React,
  t = window.wp.blocks,
  o = JSON.parse(
    '{"$schema":"https://schemas.wp.org/trunk/block.json","apiVersion":3,"title":"Jon\'s cool counter","name":"jon/the-block","editorScript":"file:./index.tsx","viewModule":"file:./view.mts","render":"file:./render.php","category":"text"}',
  );
t.registerBlockType(o, {
  edit: () => (0, e.createElement)("div", null, "counter"),
  save: () => (0, e.createElement)("div", null, "counter"),
});

plugin.php

<?php
/*
 * Plugin Name: A counter
 */

add_action(
	'init',
	function () {
		register_block_type_from_metadata(__DIR__ . '/block.json');
	}
);

render.php

<div data-wp-interactive='{"namespace":"jon/the-block"}' data-wp-context='{"val":0}'>
	<input readonly type='number' data-wp-bind--value='context.val' value='0' />
	<button data-wp-on--click='actions.inc'>+</button>
	<button data-wp-on--click='actions.dec'>-</button>
</div>

view.asset.php

<?php return array('dependencies' => array('@wordpress/interactivity'), 'version' => 'f282a2a7610fadeab6d4', 'type' => 'module');

view.js

import * as t from "@wordpress/interactivity";
var e = {
  d: (t, o) => {
    for (var r in o)
      e.o(o, r) &&
        !e.o(t, r) &&
        Object.defineProperty(t, r, { enumerable: !0, get: o[r] });
  },
  o: (t, e) => Object.prototype.hasOwnProperty.call(t, e),
};
const o =
    ((n = { getContext: () => t.getContext, store: () => t.store }),
    (a = {}),
    e.d(a, n),
    a),
  r = o.getContext;
var n, a;
o.store("jon/the-block", {
  actions: {
    inc() {
      r().val += 1;
    },
    dec() {
      r().val -= 1;
    },
  },
});