All files / src/internal/client/dom hydration.js

100% Statements 71/71
100% Branches 16/16
100% Functions 3/3
100% Lines 70/70

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 712x 2x 2x 2x 2x 2x 2x 2x 2x 2x 4294x 4294x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 1430x 1430x 2x 2x 2x 2x 2x 2x 2x 2x 2x 12491x 5973x 5973x 6518x 6518x 6518x 6518x 12491x 5x 5x 6513x 6513x 6513x 6513x 6513x 12491x 39450x 26474x 26474x 26474x 9981x 26474x 16492x 6511x 6511x 6511x 9981x 9981x 9981x 26474x 32939x 32939x 32939x 2x 2x 2x  
import { HYDRATION_END, HYDRATION_START } from '../../../constants.js';
 
/**
 * Use this variable to guard everything related to hydration code so it can be treeshaken out
 * if the user doesn't use the `hydrate` method and these code paths are therefore not needed.
 */
export let hydrating = false;
 
/** @param {boolean} value */
export function set_hydrating(value) {
	hydrating = value;
}
 
/**
 * Array of nodes to traverse for hydration. This will be null if we're not hydrating, but for
 * the sake of simplicity we're not going to use `null` checks everywhere and instead rely on
 * the `hydrating` flag to tell whether or not we're in hydration mode at which point this is set.
 * @type {import('#client').TemplateNode[]}
 */
export let hydrate_nodes = /** @type {any} */ (null);
 
/** @param {import('#client').TemplateNode[]} nodes */
export function set_hydrate_nodes(nodes) {
	hydrate_nodes = nodes;
}
 
/**
 * This function is only called when `hydrating` is true. If passed a `<!--[-->` opening
 * hydration marker, it finds the corresponding closing marker and sets `hydrate_nodes`
 * to everything between the markers, before returning the closing marker.
 * @param {Node} node
 * @returns {Node}
 */
export function hydrate_anchor(node) {
	if (node.nodeType !== 8) {
		return node;
	}
 
	var current = /** @type {Node | null} */ (node);
 
	// TODO this could have false positives, if a user comment consisted of `[`. need to tighten that up
	if (/** @type {Comment} */ (current)?.data !== HYDRATION_START) {
		return node;
	}
 
	/** @type {Node[]} */
	var nodes = [];
	var depth = 0;
 
	while ((current = /** @type {Node} */ (current).nextSibling) !== null) {
		if (current.nodeType === 8) {
			var data = /** @type {Comment} */ (current).data;
 
			if (data === HYDRATION_START) {
				depth += 1;
			} else if (data[0] === HYDRATION_END) {
				if (depth === 0) {
					hydrate_nodes = /** @type {import('#client').TemplateNode[]} */ (nodes);
					return current;
				}
 
				depth -= 1;
			}
		}
 
		nodes.push(current);
	}
 
	throw new Error('Expected a closing hydration marker');
}