Function loadAndExtractMap

packages/core/inspector_modules.ts:77–136

(mapPath: string, fallbackJsPath?: string)

}

function loadAndExtractMap(mapPath: string, fallbackJsPath?: string) {
	// check cache first
	if (!loadedSourceMaps) {
		loadedSourceMaps = new Map();
	}
	let mapText = loadedSourceMaps.get(mapPath);
	if (mapText) {
		return mapText; // already loaded
	} else {
		if (File.exists(mapPath)) {
			try {
				const contents = File.fromPath(mapPath).readTextSync();

				// Note: we may want to do this, keeping for reference if needed in future.
				// Check size before processing (skip very large source maps)
				// const maxSizeBytes = 10 * 1024 * 1024; // 10MB limit
				// if (contents.length > maxSizeBytes) {
				// 	console.warn(`Source map ${mapPath} is too large (${contents.length} bytes), skipping...`);
				// 	return null;
				// }

				if (usingSourceMapFiles) {
					mapText = contents;
				} else {
					// parse out the inline base64
					const match = contents.match(/\/\/[#@] sourceMappingURL=data:application\/json[^,]+,(.+)$/);
					if (!match) {
						console.warn(`Invalid source map format in ${mapPath}`);
						return null;
					}
					const base64 = match[1];
					const binary = atob(base64);
					// this is the raw text of the source map
					// seems to work without doing decodeURIComponent tricks
					mapText = binary;
				}
			} catch (error) {
				console.debug && console.debug(`Failed to load source map ${mapPath}:`, error);
				return null;
			}
		} else {
			// Try fallback: read inline or linked map from the JS file itself
			if (fallbackJsPath) {
				const alt = findInlineOrLinkedMapFromJs(fallbackJsPath);
				if (alt && alt.text) {
					mapText = alt.text;
					// Cache under both the requested key and the alt key so future lookups are fast
					loadedSourceMaps.set(alt.key, alt.text);
				} else {
					return null;
				}
			} else {
				// no source maps
				return null;
			}
		}
	}
	loadedSourceMaps.set(mapPath, mapText); // cache it