Fragment.js — svelte Source File

Source Code

/** @import { Expression, Statement } from 'estree' */
/** @import { AST } from '#compiler' */
/** @import { ComponentClientTransformState, ComponentContext } from '../types' */
import * as b from '#compiler/builders';
import { TEMPLATE_FRAGMENT, TEMPLATE_USE_IMPORT_NODE } from '../../../../../constants.js';
import { clean_nodes, infer_namespace } from '../../utils.js';
import { transform_template } from '../transform-template/index.js';
import { Template } from '../transform-template/template.js';
import { process_children } from './shared/fragment.js';
import { build_render_statement, Memoizer } from './shared/utils.js';

/**
 * @param {AST.Fragment} node
 * @param {ComponentContext} context
 */
export function Fragment(node, context) {
	// Creates a new block which looks roughly like this:
	// ```js
	// // hoisted:
	// const block_name = $.from_html(`...`);
	//
	// // for the main block:
	// const id = block_name();
	// // init stuff and possibly render effect
	// $.append($$anchor, id);
	// ```
	// Adds the hoisted parts to `context.state.hoisted` and returns the statements of the main block.

	const parent = context.path.at(-1) ?? node;

	const namespace = infer_namespace(context.state.metadata.namespace, parent, node.nodes);

	const { hoisted, trimmed, is_standalone, is_text_first } = clean_nodes(
		parent,
		node.nodes,
		context.path,
		namespace,
		context.state,
		context.state.preserve_whitespace,
		context.state.options.preserveComments
	);

	if (hoisted.length === 0 && trimmed.length === 0) {
		return b.block([]);
	}

	const is_single_element = trimmed.length === 1 && trimmed[0].type === 'RegularElement';
	const is_single_child_not_needing_template =
		trimmed.length === 1 &&
		(trimmed[0].type === 'SvelteFragment' ||
			trimmed[0].type === 'TitleElement' ||
			(trimmed[0].type === 'IfBlock' &&
				trimmed[0].elseif &&
				/** @type {AST.IfBlock} */ (parent).metadata.flattened?.includes(trimmed[0])));
	const template_name = context.state.scope.root.unique('root'); // TODO infer name from parent

	/** @type {Statement[]} */
	const body = [];

	/** @type {Statement | undefined} */
// ... (127 more lines)