mozilla/source-map
Source Map
This project is a source map implementation library used for generating, parsing, and consuming source maps. It provides the functional components necessary to link transformed or minified code back to original source files, acting as a tool for code transformation debugging.
The library includes a source map composer for building trees of code snippets that automatically produce output strings and mappings. It also functions as a source map merger, providing mechanisms to chain and merge multiple maps to resolve multi-step code transformations across different build stages.
The project covers bidirectional coordinate translation, allowing positions to be mapped from generated source back to original files or from original source to generated output. It provides utilities for parsing encoded mapping strings, retrieving original source content, and iterating through mapping data for programmatic analysis.
Features
- Minified Code Debugging - Translates runtime errors in minified or transformed code back to the original source files for troubleshooting.
- Source-to-Generated Code Mappings - Translates positions in generated source back to the original file, line, column, and identifier name.
- Coordinate Translation Utilities - Translates runtime error positions in generated code back to the original source file, line, and column.
- Transformation Chaining - Implements the capability to rewrite mappings by applying existing source maps to resolve multi-step transformations.
- Source Map Resolution - Provides a mechanism for chaining and merging multiple source maps to resolve multi-step code transformations.
- Source Map Generators - Creates source maps by incrementally adding mappings between original source positions and generated output positions.
- Map Merging - Provides mechanisms to merge multiple source maps to resolve combined code transformations.
- Source Map Composers - Provides a tool for building trees of code snippets that automatically generate final output strings and associated source maps.
- Source Map Implementation Libraries - Implements a full library for generating, parsing, and consuming source maps to link transformed code to original files.
- Mapped String Concatenations - Tracks offsets during code concatenation to preserve source map metadata while producing the final output string.
- Composite Source Node Trees - Builds a hierarchy of code fragments and metadata to automatically compute final positions and mappings.
- Multi-Step Map Merging - Chains and merges multiple source maps to track code changes across several build stages or compilers.
- VLQ Encodings - Uses Variable-Length Quantity encoding to compress coordinate data for efficient storage and transmission.
- Source Map Chaining - Provides mechanisms to chain multiple mapping layers, treating one map's output as another's input.
- Source Mapping Iterators - Traverses the internal coordinate list sequentially to translate every generated position back to its original source.
- Original-to-Generated Mapping - Translates a specific line and column from an original source file to its corresponding position in the generated output.
- Snippet Tracking - Provides utilities to automatically track source mappings while concatenating and interpolating generated code snippets.
- Source Map Extractions - Extracts raw content of original source files directly from the parsed source map data.
- Source Map Decoders - Decodes encoded mapping strings within a source map to determine relationships between generated and original positions.
- Node Tree Composition - Offers a composer for building trees of code snippets that automatically generate output strings and associated source maps.
- Source Mapping Iterators - Traverses every mapping between original and generated source positions using a specified sort order for analysis.
