svelte/src/compiler/compile/utils/get_name_from_filename.ts

export default function get_name_from_filename(filename: string) {
	if (!filename) return null;
	// eslint-disable-next-line no-useless-escape
	const parts = filename.split(/[\/\\]/);

	if (parts.length > 1) {
		const index_match = parts[parts.length - 1].match(/^index(\.\w+)/);
		if (index_match) {
			parts.pop();
			parts[parts.length - 1] += index_match[1];
		}
	}

	const base = parts.pop()
		.replace(/\.[^.]+$/, "")
		.replace(/[^a-zA-Z_$0-9]+/g, '_')
		.replace(/^_/, '')
		.replace(/_$/, '')
		.replace(/^(\d)/, '_$1');

	if (!base) {
		throw new Error(`Could not derive component name from file ${filename}`);
	}

	return base[0].toUpperCase() + base.slice(1);
}