Convert to es6 modules

[rkusa]

Before leaving alpha, the library should be converted to using es6 modules.

[rkusa]

Anyone aware of a tool to automatically convert a library to es6 modules?

[rkusa]

While I did an initial conversion, I am not yet sure how to handle the fact that pdfjs should work for both server and client. Since Node.js requires the file extension of .mjs

[jpbourgeon]

Hello have a look here https://github.com/nolanlawson/cjs-to-es6

Other ideas on stackoverflow https://stackoverflow.com/questions/43106130/convert-existing-legacy-library-to-es6-module

[rkusa]

Hi @jpbourgeon, thanks for the links. I have already converted the library in a local branch, but was not able to find a good es6 modules solution for libraries that target both server (Node.js) and client 😕

[jpbourgeon]

Would it help to split the library into two components and take advantage of npmjs namespaces?

Something like @pdfjs/server and @pdfjs/browser

[rkusa]

I guess there are the following options.

1) Write client-side ES modules (.js)

• ✅ does work with babel
• ✅ named imports work (e.g. import {Document} from "pdfjs"
• ❌ does not work with Node.js ES modules (since .mjs extension required)
• ❌ does not work with require
• ➡️ the code has to be transpiled back to common-js and additionally included in the module

2) Write server-side ES modules (.mjs)

• ✅ does work with babel
• ✅ named imports work (e.g. import {Document} from "pdfjs"
• ✅ does work with Node.js ES modules
• ❌ does not work with require
• ➡️ the code still has to be transpiled back to CJS modules to get require to work

3) Keep CJS modules

• ✅ does work with babel
• ❌ named imports do not work (e.g. import {Document} from "pdfjs")
• ✅ can be loaded from Node.js ES modules
• ✅ does work with require
• ➡️ only drawback seems to be that we have to write import * as pdf from "pdfjs" when loading pdfjs from ES modules (instead of being able to import named exports import {Document} from "pdfjs")

In Summary, either transpile the code for Node.js usage or live with import {Document} from "pdfjs". TBH, I really dislike both options 😕

[rkusa]

The conversion happens here https://github.com/rkusa/pdfjs/tree/es6-modules Though, the branch is unfortunately not green yet

[AllNamesRTaken]

Would it be of interest to move to TS instead of ES6?

[amotl]

Would it be of interest to move to TS instead of ES6?

I've recently had the pleasure to work on a TypeScript codebase [1] using WebStorm [2] and I want to report that the overall experience is absolutely amazing and totally washed away any hesitations I had regarding TypeScript. Finally, I feel like I can get similar productive with JavaScript as I am with Python. ES6 did not give me that feeling yet.

[1] https://github.com/hiveeyes/grafana-worldmap-panel [2] https://www.jetbrains.com/webstorm/

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@rkusa: Amazing project, greetings from Berlin and keep up the spirit!

[AllNamesRTaken]

My pet project is https://github.com/AllNamesRTaken/GoodCore outside workhours and i could help out is needed.

[amotl]

@AllNamesRTaken: Sounds interesting, thanks for letting us know. Star-given ;].

[rkusa]

Would it be of interest to move to TS instead of ES6?

I am, generally speaking, not opposed to TS.

I've recently had the pleasure to work on a TypeScript codebase [1] using WebStorm [2] and I want to report that the overall experience is absolutely amazing and totally washed away any hesitations I had regarding TypeScript.

I can confirm that. In my day job, I also work more with TS than JS and the whole TS dev experience (editor integration, less errors when refactoring, ...) is superior than JS ...

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What currently holds me off from converting the codebase to TS:

• I always disliked Coffeescript projects (example works for all other languages that compile to JS), because of the higher entry barrier for submitting a contribution - I am a bit concerned that it might be similar for people when it comes to TS ... though, I think the advantages of TS a greater than my concerns here
• The effort required to convert it
• I am not sure if I'd rather rewrite the lib in something that compiles to wasm (something that would be cooler for my personal use-case of the lib)