/**
* @typedef {import('hast').Element} Element
* @typedef {import('hast').Parents} Parents
*/
import {whitespace} from 'hast-util-whitespace'
import {siblingAfter, siblingBefore} from './util/siblings.js'
import {closing} from './closing.js'
import {omission} from './omission.js'
export const opening = omission({
body,
colgroup,
head,
html,
tbody
})
/**
* Whether to omit `<html>`.
*
* @param {Element} node
* Element.
* @returns {boolean}
* Whether the opening tag can be omitted.
*/
function html(node) {
const head = siblingAfter(node, -1)
return !head || head.type !== 'comment'
}
/**
* Whether to omit `<head>`.
*
* @param {Element} node
* Element.
* @returns {boolean}
* Whether the opening tag can be omitted.
*/
function head(node) {
const children = node.children
/** @type {Array<string>} */
const seen = []
let index = -1
while (++index < children.length) {
const child = children[index]
if (
child.type === 'element' &&
(child.tagName === 'title' || child.tagName === 'base')
) {
if (seen.includes(child.tagName)) return false
seen.push(child.tagName)
}
}
return children.length > 0
}
/**
* Whether to omit `<body>`.
*
* @param {Element} node
* Element.
* @returns {boolean}
* Whether the opening tag can be omitted.
*/
function body(node) {
const head = siblingAfter(node, -1, true)
return (
!head ||
(head.type !== 'comment' &&
!(head.type === 'text' && whitespace(head.value.charAt(0))) &&
!(
head.type === 'element' &&
(head.tagName === 'meta' ||
head.tagName === 'link' ||
head.tagName === 'script' ||
head.tagName === 'style' ||
head.tagName === 'template')
))
)
}
/**
* Whether to omit `<colgroup>`.
* The spec describes some logic for the opening tag, but it’s easier to
* implement in the closing tag, to the same effect, so we handle it there
* instead.
*
* @param {Element} node
* Element.
* @param {number | undefined} index
* Index of element in parent.
* @param {Parents | undefined} parent
* Parent of element.
* @returns {boolean}
* Whether the opening tag can be omitted.
*/
function colgroup(node, index, parent) {
const previous = siblingBefore(parent, index)
const head = siblingAfter(node, -1, true)
// Previous colgroup was already omitted.
if (
parent &&
previous &&
previous.type === 'element' &&
previous.tagName === 'colgroup' &&
closing(previous, parent.children.indexOf(previous), parent)
) {
return false
}
return Boolean(head && head.type === 'element' && head.tagName === 'col')
}
/**
* Whether to omit `<tbody>`.
*
* @param {Element} node
* Element.
* @param {number | undefined} index
* Index of element in parent.
* @param {Parents | undefined} parent
* Parent of element.
* @returns {boolean}
* Whether the opening tag can be omitted.
*/
function tbody(node, index, parent) {
const previous = siblingBefore(parent, index)
const head = siblingAfter(node, -1)
// Previous table section was already omitted.
if (
parent &&
previous &&
previous.type === 'element' &&
(previous.tagName === 'thead' || previous.tagName === 'tbody') &&
closing(previous, parent.children.indexOf(previous), parent)
) {
return false
}
return Boolean(head && head.type === 'element' && head.tagName === 'tr')
}