Autogenerate TS typedefs for Core

[arthuro555]

Adds a script that parses the Bindings.idl to generate a TypeScript DTS file, as a first step for a potential migration of the IDE from Flow to TypeScript.

[4ian]

Excellent stuff! Will be very helpful for the future or for any tooling using libGD.js directly.
The parser seems fairly concise which is helpful to avoid bringing big dependencies or complex stuff. We could probably adapt the flow generation code to be the same.

@D8H once merged, let's use this in other repos :)

[4ian]

@arthuro555 if you can fix the requested changes, then we can merge this :)

[arthuro555]

Sorry for the delay, I had left on vacation without my laptop ✌️
I've done the requested changes 👍

[4ian]

Looks good! The npm install on Travis is failing, any idea why?

[arthuro555]

Looks good! The npm install on Travis is failing, any idea why?

Hmm git probably messed up package-lock.json when merging with upstream, I regenerated it, hopefully that fixes it.

[arthuro555]

Looks like since the emsdk environement registers an old node/npm version, we needed a package-lock v1 for it to install properly

[4ian]

Nice!
I did try locally but got:

Running "shell:generateTSTypes" (shell) task
internal/modules/cjs/loader.js:981
  throw new ERR_REQUIRE_ESM(filename);
  ^

Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: /Users/florian/Projects/F/GD/GDevelop.js/scripts/generate-dts.mjs
    at Object.Module._extensions..mjs (internal/modules/cjs/loader.js:981:9)
    at Module.load (internal/modules/cjs/loader.js:790:32)
    at Function.Module._load (internal/modules/cjs/loader.js:703:12)
    at Function.Module.runMain (internal/modules/cjs/loader.js:999:10)
    at internal/main/run_main_module.js:17:11
Warning: Command failed: node scripts/generate-dts.mjs
internal/modules/cjs/loader.js:981
  throw new ERR_REQUIRE_ESM(filename);
  ^

Error [ERR_REQUIRE_ESM]: Must use import to load ES Module: /Users/florian/Projects/F/GD/GDevelop.js/scripts/generate-dts.mjs
    at Object.Module._extensions..mjs (internal/modules/cjs/loader.js:981:9)
    at Module.load (internal/modules/cjs/loader.js:790:32)
    at Function.Module._load (internal/modules/cjs/loader.js:703:12)
    at Function.Module.runMain (internal/modules/cjs/loader.js:999:10)
    at internal/main/run_main_module.js:17:11
 Use --force to continue.

node -v gives v12.9.1. Can you confirm what Node version you have locally when in the Emscripten environment?
Looks like the CI might be using a more recent version.

[4ian]

I suggest I convert the script back to "good old" require, so that this is "safe" with older Node.js version - whatever the system/CI/emscripten version. So we can then merge this and ensure it always work.

[arthuro555]

Node supports esm since v14. v14, v16 in 5 days from today, and all versions below, all have reached end of life. Instead of doing additional work to convert this script back to cjs "just in case", we should rather use the energy to update CIs & the like from very outdated node versions to an actually supported version of node.

[arthuro555]

For emscripten specifically, I just tried and GDevelop.js builds perfectly fine (albeit with a few C++17 deprecation warnings for using binary_function) under the latest version of emscripten, where emsdk's environment uses Node v16.

[4ian]

If you're fine for this PR to land later, we can then take the time to upgrade Emscripten.

[4ian]

So Travis CI failing because lock file is probably too old.
And Semaphore failing because... it never manages to do the newIDE tests (??).

Let's regenerate, again, the package-lock.json with at least Node.js 16 bundled with Emscripten?
EDIT: done

[4ian]

Finally merged! I almost think we could generate the Flow types like you did with a simple parser, rather than relying on the complicated webidl-tools-flow.