fix: add cross-platform build support for Windows (replace rm/cp with cross-platform alternatives) (#1054)

* fix: add cross-platform build support for Windows

- Replace rm -rf with rimraf for cross-platform directory cleanup
- Add Node.js copy script to replace Unix cp command
- Makes build process work on Windows

* chore: update package-lock.json for rimraf dependency

- Adds rimraf to package-lock.json for reproducible installs
- Ensures npm ci works correctly

This fixes the CI failure reported in PR review.

* fix(build): use rimraf v5 for Node 18 compatibility

- Use rimraf@5.0.5 (supports Node 14+) instead of v6
- Add copy-assets.js for cross-platform file copying
- Maintains Windows compatibility while supporting Node 18

This PR now works with the project's Node 18 requirement.

* fix: replace rimraf with node stdlib clean for engine compat

rimraf@5/6 requires Node >=20 via path-scurry@2, but engines say >=18.
Replace with core/scripts/clean.js using fs.rmSync.

Also strip UTF-8 BOM from core/scripts/copy-assets.js and delete the
duplicate root-level scripts/copy-assets.js.

---------

Co-authored-by: Samuel EF. Tinnerholm <samuel.tinnerholm@gmail.com>

Author: AbhilashG12

core/package.json

@@ -22,9 +22,9 @@
     "test": "test"
   },
   "scripts": {
-    "clean": "rm -rf dist",
+    "clean": "node scripts/clean.js",
     "prebuild": "npm run clean",
-    "build": "tsc && cp src/server/openapi.yaml dist/server/openapi.yaml && cp src/server/method-verbs.json dist/server/method-verbs.json",
+    "build": "tsc && node scripts/copy-assets.js",
     "bundle:server": "npm run build && esbuild dist/server/index.js --bundle --platform=node --target=node18 --outfile=dist/server/bundled.js --define:__PMXT_VERSION__=\\\"$npm_package_version\\\" --external:fsevents --external:@opinion-labs/opinion-clob-sdk",
     "test": "jest -c jest.config.js",
     "server": "tsx watch src/server/index.ts",
@@ -55,11 +55,11 @@
     "cors": "^2.8.5",
     "dotenv": "^17.2.3",
     "ethers": "^5.8.0",
-    "viem": "^2.0.0",
     "express": "^5.2.1",
     "isows": "^1.0.6",
     "msgpackr": "^2.0.1",
     "polymarket-us": "0.1.1",
+    "viem": "^2.0.0",
     "ws": "^8.18.0"
   },
   "devDependencies": {

core/scripts/clean.js

@@ -0,0 +1,6 @@
+const fs = require("fs");
+
+const target = "dist";
+
+fs.rmSync(target, { recursive: true, force: true });
+console.log("Cleaned " + target);

core/scripts/copy-assets.js

@@ -0,0 +1,16 @@
+const fs = require("fs");
+const path = require("path");
+
+const assets = [
+  { src: "src/server/openapi.yaml", dest: "dist/server/openapi.yaml" },
+  { src: "src/server/method-verbs.json", dest: "dist/server/method-verbs.json" }
+];
+
+assets.forEach(asset => {
+  const destDir = path.dirname(asset.dest);
+  if (!fs.existsSync(destDir)) {
+    fs.mkdirSync(destDir, { recursive: true });
+  }
+  fs.copyFileSync(asset.src, asset.dest);
+  console.log("Copied " + asset.src + " -> " + asset.dest);
+});