postinstall.js

// this is run after npm install
// download pre-made module, if possible & exit 1, or exit 0 to tell system if it needs to build

const { fs } = require("node:fs/promises");
const path = require("node:path");
const fetch = require("cross-fetch");

let targetPath = path.join(
  __dirname,
  "..",
  "build",
  "Release",
  "node-raylib.node"
);

const { version } = require("../package.json");

function toBuffer(ab) {
  const buf = Buffer.alloc(ab.byteLength);
  const view = new Uint8Array(ab);
  for (let i = 0; i < buf.length; ++i) {
    buf[i] = view[i];
  }
  return buf;
}

async function exists(path) {
  try {
    await fs.access(path);
    return true;
  } catch {
    return false;
  }
}

async function main() {
  if (await exists(targetPath)) {
    console.log("Found node-raylib.node.");
    process.exit(0);
  }

  let url = `https://github.com/RobLoach/node-raylib/releases/download/v${version}/node-raylib-${process.platform}-${process.arch}.node`;

  // we use a single build for both platforms on Mac
  if (process.platform === 'darwin') {
    url = `https://github.com/RobLoach/node-raylib/releases/download/v${process.env.npm_package_version}/node-raylib-darwin.node`
  }

  console.log(`Checking for ${url}`)

  try {
    await fs.mkdir(path.join(__dirname, "..", "build"));
  } catch (e) {}

  try {
    await fs.mkdir(path.join(__dirname, "..", "build", "Release"));
  } catch (e) {}

  if (
    process.platform === "linux" &&
    (process.arch === "arm" || process.arch === "arm64")
  ) {
    targetPath = path.join(
      __dirname,
      "..",
      "build",
      "Release",
      "node-raylib-drm.node"
    );
    url = `https://github.com/RobLoach/node-raylib/releases/download/v${version}/node-raylib-${process.platform}-${process.arch}-drm.node`;
    try {
      const data = await fetch(url)
        .then((r) => {
          if (r.status !== 200) {
            throw new Error(`Status: ${r.status}`);
          }
          return r;
        })
        .then((r) => r.arrayBuffer());
      await fs.writeFile(targetPath, toBuffer(data));
      console.log("Found DRM on releases.");
    } catch (e) {}
  }

  try {
    const data = await fetch(url)
      .then((r) => {
        if (r.status !== 200) {
          throw new Error(`Status: ${r.status}`);
        }
        return r;
      })
      .then((r) => r.arrayBuffer());
    await fs.writeFile(targetPath, toBuffer(data));
    console.log("Found on releases.");
    process.exit(0);
  } catch (e) {
    console.error(e.message);
  }

  // couldn't find it, so tell postinstall to compile it
  console.log("Not found. Building.");
  process.exit(1);
}
main();