Description

I think there is some problem with sourcemaps generation, in that it produces lines/columns with negative indexes. I'm not 100% sure because I'm not an expert in the sourcemaps format, but I've got errors from webpack+purs-loader and using the source-map npm package, which makes me believe they are indeed incorrect.

To Reproduce

I'll give the steps I've used under Windows 10, but there shouldn't be any difference in other environments

• install purescript and spago globally
• create a new directory
• run "spago init"
• run "spago build"
• run "npm init -y"
• install source-map package: "npm install source-map --save"
• save a script in the project root with this content:

const s = require("source-map");
const fs = require("fs");
const path = require("path");
const content = fs.readFileSync(path.join(__dirname, "output", "Effect.Console", "index.js.map"), {encoding: "utf-8"});
s.SourceMapConsumer.with(
  JSON.parse(content),
  null,
  (consumer) => {
    console.log("sources:");
    console.log(consumer.sources);

    console.log("mappings:");
    consumer.eachMapping(function (m) {
      console.log(JSON.stringify(m));
    });
  }
)
  .then(() => console.log("all done"))
  .catch(console.error);

• run the script

Expected behavior

It should print a list of mappings between Effect.Console's purescript sources and generated javascript sources. Instead, it fails with an error:

sources:
[ '..\\..\\.spago\\console\\v5.0.0\\src\\Effect\\Console.purs' ]
mappings:
Error: Error parsing mappings (code 1): the mappings contained a negative line, column, source index, or name index
    at BasicSourceMapConsumer._parseMappings (E:\Documents\projects\smbug\node_modules\source-map\lib\source-map-consumer.js:360:13)
    at BasicSourceMapConsumer._getMappingsPtr (E:\Documents\projects\smbug\node_modules\source-map\lib\source-map-consumer.js:315:12)
    at E:\Documents\projects\smbug\node_modules\source-map\lib\source-map-consumer.js:387:57
    at Object.withMappingCallback (E:\Documents\projects\smbug\node_modules\source-map\lib\wasm.js:95:11)
    at BasicSourceMapConsumer.eachMapping (E:\Documents\projects\smbug\node_modules\source-map\lib\source-map-consumer.js:371:16)
    at E:\Documents\projects\smbug\test.js:13:14
    at E:\Documents\projects\smbug\node_modules\source-map\lib\source-map-consumer.js:78:16

Additional context

Spago version: 0.19.1
source-map package version: 0.7.3
psc: psc-0.14.0-20210318

PureScript version

0.14.0