var assert = require('mdast-util-assert')

assert({type: 'root', children: []})
assert({type: 'break'})
assert({type: 'listItem', checked: true, children: []})
// All OK.

assert({children: []})
// AssertionError: node should have a type: `{ children: [] }`

assert({type: 'paragraph', value: 'foo'})
// AssertionError: parent should have children: `{ type: 'paragraph', value: 'foo' }`