Bump source-map dependency

[BlueskyFR]

trafficstars

Hi!

I am trying to locally upgrade the source-map dependency. As of now, the following code is initializing it:

public static get consumer(): SourceMapConsumer {
  if (this._consumer == null) {
    this._consumer = new SourceMapConsumer(require("main.js.map"));
  }

  return this._consumer;
}

However, the new SourceMapConsumer now returns a promise, which makes the source-map parsing asynchronous. The problem is that a getter cannot be async.

How can I handle this? I am considering doing a PR after I resolve this.

Thanks in advance for your help!

[pyrodogg]

Referencing mozilla/source-map#331, I don't think it's possible to use versions higher than 0.6.1 which is what we're targeting.

Is there is some new feature of source-map that you really need, or are you just trying to run the latest version because it's newer?

It might be worth making your case for needing a sync version of the latest source-map on the referenced issue.

[BlueskyFR]

I am trying to upgrade the source-map dependency for many reasons, mainly because the dependencies of this project have not been updated for 2 to 3 years so I am basically trying to upgrade everything to increase the global stability and get the benefits of performance improvements. Using the async version of source-map can be really great because parsing a source-map requires a lot of computation compared to the other operations that a screeps script does, so doing it asynchronously can help I guess.

[BlueskyFR]

Is there is some new feature of source-map that you really need

So I would say that I "need" the performance improvements that have been made since the 0.6.1 version.

The async parsing is not a problem for me, which is different from the issue you referenced: I just need to figure out a clean way to handle it.

[BlueskyFR]

@pyrodogg @resir014 Can you help?

[BlueskyFR]

Referencing mozilla/source-map#331, I don't think it's possible to use versions higher than 0.6.1 which is what we're targeting.

@pyrodogg What is the problem to asynchronously throw errors?

[pyrodogg]

The problem isn't inherently that it's an async library. Promises do exist and operate within the screeps game loop. The problem really comes from looking at why source-map is async.

// https://github.com/mozilla/source-map/blob/master/lib/read-wasm.js
const fs = require("fs");
const path = require("path");

module.exports = function readWasm() {
  return new Promise((resolve, reject) => {
    const wasmPath = path.join(__dirname, "mappings.wasm");
    fs.readFile(wasmPath, null, (error, data) => {
      if (error) {
        reject(error);
        return;
      }

      resolve(data.buffer);
    });
  });
};

It's async because it's reading the wasm module with fs.readFile, which isn't available in screeps.

There are other issues on that project that seems to point at working around it. https://github.com/mozilla/source-map/issues/372 https://github.com/mozilla/source-map/pull/339 https://github.com/mozilla/source-map/pull/369

It looks like node version of source-map needs a method to receive wasm as a synchronous parameter so that it could be loaded with require() and not rely on fs.