parse_attached_sourcemap() — svelte Function Reference

Architecture documentation for the parse_attached_sourcemap() function in mapped_code.js from the svelte codebase.

Function javascript Compiler Migrator calls 1 called by 1

Entity Profile

Compiler→ Migrator→ parse_attached_sourcemap() — svelte Function Reference

Dependency Diagram

graph TD
  b39edb0f_ea67_1ea3_e86a_954e5131b3cd["parse_attached_sourcemap()"]
  d383a41d_5383_ee86_cab6_03bf1a2daf93["mapped_code.js"]
  b39edb0f_ea67_1ea3_e86a_954e5131b3cd -->|defined in| d383a41d_5383_ee86_cab6_03bf1a2daf93
  860c55db_f911_8bca_7055_338865a9f9b0["processed_tag_to_code()"]
  860c55db_f911_8bca_7055_338865a9f9b0 -->|calls| b39edb0f_ea67_1ea3_e86a_954e5131b3cd
  32acb77a_d3b2_7ed6_c472_32354754ebf0["b64dec()"]
  b39edb0f_ea67_1ea3_e86a_954e5131b3cd -->|calls| 32acb77a_d3b2_7ed6_c472_32354754ebf0
  style b39edb0f_ea67_1ea3_e86a_954e5131b3cd fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/svelte/src/compiler/utils/mapped_code.js lines 341–387

export function parse_attached_sourcemap(processed, tag_name) {
	const r_in = '[#@]\\s*sourceMappingURL\\s*=\\s*(\\S*)';
	const regex =
		tag_name == 'script'
			? new RegExp('(?://' + r_in + ')|(?:/\\*' + r_in + '\\s*\\*/)$')
			: new RegExp('/\\*' + r_in + '\\s*\\*/$');

	/**
	 * @param {any} message
	 */
	function log_warning(message) {
		// code_start: help to find preprocessor
		const code_start =
			processed.code.length < 100 ? processed.code : processed.code.slice(0, 100) + ' [...]';
		// eslint-disable-next-line no-console
		console.warn(`warning: ${message}. processed.code = ${JSON.stringify(code_start)}`);
	}
	processed.code = processed.code.replace(regex, (_, match1, match2) => {
		const map_url = tag_name == 'script' ? match1 || match2 : match1;
		const map_data = (map_url.match(regex_data_uri) || [])[1];
		if (map_data) {
			// sourceMappingURL is data URL
			if (processed.map) {
				log_warning(
					'Not implemented. ' +
						'Found sourcemap in both processed.code and processed.map. ' +
						'Please update your preprocessor to return only one sourcemap.'
				);
				// ignore attached sourcemap
				return '';
			}
			processed.map = b64dec(map_data); // use attached sourcemap
			return ''; // remove from processed.code
		}
		// sourceMappingURL is path or URL
		if (!processed.map) {
			log_warning(
				`Found sourcemap path ${JSON.stringify(
					map_url
				)} in processed.code, but no sourcemap data. ` +
					'Please update your preprocessor to return sourcemap data directly.'
			);
		}
		// ignore sourcemap path
		return ''; // remove from processed.code
	});
}