ui/node_modules/svelte/src/compiler/compile/index.js

import Stats from '../Stats.js';
import parse from '../parse/index.js';
import render_dom from './render_dom/index.js';
import render_ssr from './render_ssr/index.js';
import Component from './Component.js';
import fuzzymatch from '../utils/fuzzymatch.js';
import get_name_from_filename from './utils/get_name_from_filename.js';
import { valid_namespaces } from '../utils/namespaces.js';

const valid_options = [
	'name',
	'filename',
	'sourcemap',
	'enableSourcemap',
	'generate',
	'errorMode',
	'varsReport',
	'outputFilename',
	'cssOutputFilename',
	'sveltePath',
	'dev',
	'accessors',
	'immutable',
	'hydratable',
	'legacy',
	'customElement',
	'namespace',
	'tag',
	'css',
	'loopGuardTimeout',
	'preserveComments',
	'preserveWhitespace',
	'cssHash',
	'discloseVersion'
];
const valid_css_values = [true, false, 'injected', 'external', 'none'];
const regex_valid_identifier = /^[a-zA-Z_$][a-zA-Z_$0-9]*$/;
const regex_starts_with_lowercase_character = /^[a-z]/;

let warned_of_format = false;
let warned_boolean_css = false;

/**
 * @param {import('../interfaces.js').CompileOptions} options
 * @param {import('../interfaces.js').Warning[]} warnings
 */
function validate_options(options, warnings) {
	if (/** @type {any} */ (options).format) {
		if (!warned_of_format) {
			warned_of_format = true;
			console.warn(
				'The format option has been removed in Svelte 4, the compiler only outputs ESM now. Remove "format" from your compiler options. ' +
					'If you did not set this yourself, bump the version of your bundler plugin (vite-plugin-svelte/rollup-plugin-svelte/svelte-loader)'
			);
		}
		delete (/** @type {any} */ (options).format);
	}

	const { name, filename, loopGuardTimeout, dev, namespace, css } = options;
	Object.keys(options).forEach((key) => {
		if (!valid_options.includes(key)) {
			const match = fuzzymatch(key, valid_options);
			let message = `Unrecognized option '${key}'`;
			if (match) message += ` (did you mean '${match}'?)`;
			throw new Error(message);
		}
	});
	if (name && !regex_valid_identifier.test(name)) {
		throw new Error(`options.name must be a valid identifier (got '${name}')`);
	}
	if (name && regex_starts_with_lowercase_character.test(name)) {
		const message = 'options.name should be capitalised';
		warnings.push({
			code: 'options-lowercase-name',
			message,
			filename,
			toString: () => message
		});
	}
	if (loopGuardTimeout && !dev) {
		const message = 'options.loopGuardTimeout is for options.dev = true only';
		warnings.push({
			code: 'options-loop-guard-timeout',
			message,
			filename,
			toString: () => message
		});
	}

	if (css === true || css === false) {
		options.css = css === true ? 'injected' : 'external';
		if (!warned_boolean_css) {
			console.warn(
				`compilerOptions.css as a boolean is deprecated. Use '${options.css}' instead of ${css}.`
			);
			warned_boolean_css = true;
		}
	}

	if (!valid_css_values.includes(options.css)) {
		throw new Error(
			`compilerOptions.css must be 'injected', 'external' or 'none' (got '${options.css}').`
		);
	}

	if (namespace && valid_namespaces.indexOf(namespace) === -1) {
		const match = fuzzymatch(namespace, valid_namespaces);
		if (match) {
			throw new Error(`Invalid namespace '${namespace}' (did you mean '${match}'?)`);
		} else {
			throw new Error(`Invalid namespace '${namespace}'`);
		}
	}

	if (options.discloseVersion == undefined) {
		options.discloseVersion = true;
	}
}

/**
 * `compile` takes your component source code, and turns it into a JavaScript module that exports a class.
 *
 * https://svelte.dev/docs/svelte-compiler#svelte-compile
 * @param {string} source
 * @param {import('../interfaces.js').CompileOptions} options
 */
export default function compile(source, options = {}) {
	options = Object.assign(
		{ generate: 'dom', dev: false, enableSourcemap: true, css: 'injected' },
		options
	);
	const stats = new Stats();
	const warnings = [];
	validate_options(options, warnings);
	stats.start('parse');
	const ast = parse(source, options);
	stats.stop('parse');
	stats.start('create component');
	const component = new Component(
		ast,
		source,
		options.name || get_name_from_filename(options.filename) || 'Component',
		options,
		stats,
		warnings
	);
	stats.stop('create component');
	const result =
		options.generate === false
			? null
			: options.generate === 'ssr'
			? render_ssr(component, options)
			: render_dom(component, options);
	return component.generate(result);
}