await.js — svelte Source File

Source Code

/** @import { Source, TemplateNode } from '#client' */
import { is_promise } from '../../../shared/utils.js';
import { block } from '../../reactivity/effects.js';
import { internal_set, mutable_source, source } from '../../reactivity/sources.js';
import {
	hydrate_next,
	hydrating,
	skip_nodes,
	set_hydrate_node,
	set_hydrating
} from '../hydration.js';
import { queue_micro_task } from '../task.js';
import { HYDRATION_START_ELSE, UNINITIALIZED } from '../../../../constants.js';
import { is_runes } from '../../context.js';
import { Batch, flushSync, is_flushing_sync } from '../../reactivity/batch.js';
import { BranchManager } from './branches.js';
import { capture, unset_context } from '../../reactivity/async.js';

const PENDING = 0;
const THEN = 1;
const CATCH = 2;

/** @typedef {typeof PENDING | typeof THEN | typeof CATCH} AwaitState */

/**
 * @template V
 * @param {TemplateNode} node
 * @param {(() => any)} get_input
 * @param {null | ((anchor: Node) => void)} pending_fn
 * @param {null | ((anchor: Node, value: Source<V>) => void)} then_fn
 * @param {null | ((anchor: Node, error: unknown) => void)} catch_fn
 * @returns {void}
 */
export function await_block(node, get_input, pending_fn, then_fn, catch_fn) {
	if (hydrating) {
		hydrate_next();
	}

	var runes = is_runes();

	var v = /** @type {V} */ (UNINITIALIZED);
	var value = runes ? source(v) : mutable_source(v, false, false);
	var error = runes ? source(v) : mutable_source(v, false, false);

	var branches = new BranchManager(node);

	block(() => {
		var input = get_input();
		var destroyed = false;

		/** Whether or not there was a hydration mismatch. Needs to be a `let` or else it isn't treeshaken out */
		// @ts-ignore coercing `node` to a `Comment` causes TypeScript and Prettier to fight
		let mismatch = hydrating && is_promise(input) === (node.data === HYDRATION_START_ELSE);

		if (mismatch) {
			// Hydration mismatch: remove everything inside the anchor and start fresh
			set_hydrate_node(skip_nodes());
			set_hydrating(false);
		}

// ... (83 more lines)