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 4347x 4347x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 2x 1446x 1446x 2x 2x 2x 2x 2x 2x 2x 2x 2x 12606x 6043x 6043x 6563x 6563x 6563x 6563x 12606x 5x 5x 6558x 6558x 6558x 6558x 6558x 12606x 39671x 26593x 26593x 26593x 10018x 26593x 16574x 6556x 6556x 6556x 10018x 10018x 10018x 26593x 33115x 33115x 33115x 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');
}