sourcemap

A tool for generating sourcemaps based on input/output files in linear time.

Example

File foo.js:

/**
 * @return {string}
 */
function foo() {
    return "foo";
}

File bar.js:

console.log(foo());

Say you have a build procedure which concatenates these files and removes comments and spaces, producing script.js:

function foo(){return "foo";}console.log(foo());

The tool will will generate sourcemap v3:

lushnikov:~/prog/sourcemap(master)$ python gensm.py foo.js bar.js script.js > script.js.map
lushnikov:~/prog/sourcemap(master)$ cat script.js.map
{"mappings": "AAGA,SAAS,MACL,QAAQ,MCJZ,QAAQ,IAAI", "sourceRoot": "http://localhost:8090", "sources": ["foo.js", "bar.js"], "version": 3, "names": [], "file": "script.js"}

Notes:

sourceRoot is set to localhost; change it to whatever you want.
order of input files is crucial. If the script fails to match inputs with output, it fails with exception Exception: Failed to match generated and source files
Algorithm has linear complexity, though the current implementation is not quite fast and produces ~100k of sourcemapping in a second.

aslushnikov/generate-sourcemap

sourcemap

Example