add cache-busting

server/version.js

@@ -0,0 +1,23 @@
+const fs = require("fs");
+const path = require("path");
+const { execSync } = require("child_process");
+
+function getVersion() {
+  const pkg = JSON.parse(
+    fs.readFileSync(path.join(__dirname, "..", "package.json"), "utf-8"),
+  );
+  const semver = pkg.version;
+
+  let hash;
+  try {
+    hash = execSync("git rev-parse --short=7 HEAD", {
+      encoding: "utf-8",
+    }).trim();
+  } catch (e) {
+    hash = Date.now().toString(36).slice(-7);
+  }
+
+  return `${semver}-${hash}`;
+}
+
+module.exports = { getVersion };