refactored upload away from multipart forms to binary data

server/limiter.js

@@ -0,0 +1,20 @@
+const { Transform } = require('stream');
+
+class Limiter extends Transform {
+  constructor(limit) {
+    super();
+    this.limit = limit;
+    this.length = 0;
+  }
+
+  _transform(chunk, encoding, callback) {
+    this.length += chunk.length;
+    this.push(chunk);
+    if (this.length > this.limit) {
+      return callback(new Error('limit'));
+    }
+    callback();
+  }
+}
+
+module.exports = Limiter;