legacy.js — svelte Source File

Architecture documentation for legacy.js, a javascript file in the svelte codebase. 4 imports, 1 dependents.

File javascript Compiler Migrator 4 imports 1 dependents 2 functions

Entity Profile

Compiler→ Migrator→ legacy.js — svelte Source File

Dependency Diagram

graph LR
  21beed52_94ea_f810_11b8_87a2cf50432f["legacy.js"]
  ce051dbd_4cf1_f117_d66e_12cfa122de37["patterns.js"]
  21beed52_94ea_f810_11b8_87a2cf50432f --> ce051dbd_4cf1_f117_d66e_12cfa122de37
  d1869e84_a713_3c60_3aae_40e1a6b78424["extract_svelte_ignore.js"]
  21beed52_94ea_f810_11b8_87a2cf50432f --> d1869e84_a713_3c60_3aae_40e1a6b78424
  4422a3ac_4abf_f704_22f3_7d5d175ce307["extract_svelte_ignore"]
  21beed52_94ea_f810_11b8_87a2cf50432f --> 4422a3ac_4abf_f704_22f3_7d5d175ce307
  c49ac9f8_b355_57a2_8d10_b5fd945c6144["zimmerframe"]
  21beed52_94ea_f810_11b8_87a2cf50432f --> c49ac9f8_b355_57a2_8d10_b5fd945c6144
  cc8de3ad_4bae_f883_44db_d90442053943["index.js"]
  cc8de3ad_4bae_f883_44db_d90442053943 --> 21beed52_94ea_f810_11b8_87a2cf50432f
  style 21beed52_94ea_f810_11b8_87a2cf50432f fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

/** @import { Expression } from 'estree' */
/** @import { AST } from '#compiler' */
/** @import * as Legacy from './types/legacy-nodes.js' */
import { walk } from 'zimmerframe';
import {
	regex_ends_with_whitespaces,
	regex_not_whitespace,
	regex_starts_with_whitespaces
} from './phases/patterns.js';
import { extract_svelte_ignore } from './utils/extract_svelte_ignore.js';

/**
 * Some of the legacy Svelte AST nodes remove whitespace from the start and end of their children.
 * @param {AST.TemplateNode[]} nodes
 */
function remove_surrounding_whitespace_nodes(nodes) {
	const first = nodes.at(0);
	const last = nodes.at(-1);

	if (first?.type === 'Text') {
		if (!regex_not_whitespace.test(first.data)) {
			nodes.shift();
		} else {
			first.data = first.data.replace(regex_starts_with_whitespaces, '');
		}
	}
	if (last?.type === 'Text') {
		if (!regex_not_whitespace.test(last.data)) {
			nodes.pop();
		} else {
			last.data = last.data.replace(regex_ends_with_whitespaces, '');
		}
	}
}

/**
 * Transform our nice modern AST into the monstrosity emitted by Svelte 4
 * @param {string} source
 * @param {AST.Root} ast
 * @returns {Legacy.LegacyRoot}
 */
export function convert(source, ast) {
	const root = /** @type {AST.SvelteNode | Legacy.LegacySvelteNode} */ (ast);

	return /** @type {Legacy.LegacyRoot} */ (
		walk(root, null, {
			_(node, { next }) {
				// @ts-ignore
				delete node.metadata;
				next();
			},
			// @ts-ignore
			Root(node, { visit }) {
				const { instance, module, options } = node;

				// Insert svelte:options back into the root nodes
				if (/** @type {any} */ (options)?.__raw__) {
					let idx = node.fragment.nodes.findIndex(
						(node) => /** @type {any} */ (options).end <= node.start
					);
// ... (573 more lines)