mozilla/source-map

Source Map is a JavaScript library from Mozilla for reading and writing source maps. A source map is a file that connects minified or compiled code back to the original source files that produced it. When something goes wrong in a web app and you see an error in the browser's developer tools, the error normally points to a line in a compressed, unreadable file. A source map lets the browser show you the corresponding line in the original, human-readable code instead. This library handles both directions. You can use it to generate source maps when building a tool that transforms or compiles JavaScript, and you can use it to consume existing source maps to look up where a position in generated code came from in the original source. It works in Node.js (installed via npm) and in the browser (loaded via a script tag). The library uses a WebAssembly component to process mappings efficiently, which is why browser usage requires a short initialization step to point the library at the compiled WebAssembly file. The README is detailed and documents the full API surface, including a high-level interface for building source maps incrementally and a lower-level interface for adding mappings individually. The project is maintained by Mozilla and is released as an open source npm package. The full README is longer than what was shown.