Method getSourceMapForModule

lib/lbt/bundle/Builder.js:667–751

({moduleName, moduleContent, resourcePath})

	}

	async getSourceMapForModule({moduleName, moduleContent, resourcePath}) {
		let moduleSourceMap = null;
		let newModuleContent = moduleContent;

		const sourceMapUrlMatch = moduleContent.match(sourceMappingUrlPattern);
		if (sourceMapUrlMatch) {
			const sourceMapUrl = sourceMapUrlMatch[1];
			log.silly(`Found source map reference in content of module ${moduleName}: ${sourceMapUrl}`);

			// Strip sourceMappingURL from module code to be bundled
			// It has no effect and might be cause for confusion
			newModuleContent = moduleContent.replace(sourceMappingUrlPattern, "");

			if (sourceMapUrl) {
				if (sourceMapUrl.startsWith("data:")) {
					// Data-URI indicates an inline source map
					const expectedTypeAndEncoding = "data:application/json;charset=utf-8;base64,";
					if (sourceMapUrl.startsWith(expectedTypeAndEncoding)) {
						const base64Content = sourceMapUrl.slice(expectedTypeAndEncoding.length);
						moduleSourceMap = Buffer.from(base64Content, "base64").toString();
					} else {
						log.warn(
							`Source map reference in module ${moduleName} is a data URI but has an unexpected` +
							`encoding: ${sourceMapUrl}. Expected it to start with ` +
							`"data:application/json;charset=utf-8;base64,"`);
					}
				} else if (httpPattern.test(sourceMapUrl)) {
					log.warn(`Source map reference in module ${moduleName} is an absolute URL. ` +
						`Currently, only relative URLs are supported.`);
				} else if (path.posix.isAbsolute(sourceMapUrl)) {
					log.warn(`Source map reference in module ${moduleName} is an absolute path. ` +
						`Currently, only relative paths are supported.`);
				} else {
					const sourceMapPath = path.posix.join(path.posix.dirname(moduleName), sourceMapUrl);

					try {
						const sourceMapResource = await this.pool.findResource(sourceMapPath);
						moduleSourceMap = (await sourceMapResource.buffer()).toString();
					} catch (e) {
						// No input source map
						log.warn(`Unable to read source map for module ${moduleName}: ${e.message}`);
					}
				}
			}
		} else {
			const sourceMapFileCandidate = resourcePath.slice("/resources/".length) + ".map";
			log.silly(`Could not find a sourceMappingURL reference in content of module ${moduleName}. ` +
				`Attempting to find a source map resource based on the module's path: ${sourceMapFileCandidate}`);
			try {
				const sourceMapResource = await this.pool.findResource(sourceMapFileCandidate);
				moduleSourceMap = (await sourceMapResource.buffer()).toString();
			} catch (e) {
				// No input source map
				log.silly(`Could not find a source map for module ${moduleName}: ${e.message}`);
			}
		}