Add UI to prevent assigning more than 10 asignees

app/javascript/controllers/assignment_limit_controller.js

@@ -0,0 +1,26 @@
+import { Controller } from "@hotwired/stimulus"
+
+export default class extends Controller {
+  static values = { limit: Number, count: Number }
+  static targets = ["unassigned", "limitMessage"]
+
+  connect() {
+    this.updateState()
+  }
+
+  countValueChanged() {
+    this.updateState()
+  }
+
+  updateState() {
+    const atLimit = this.countValue >= this.limitValue
+
+    this.unassignedTargets.forEach(el => {
+      el.hidden = atLimit
+    })
+
+    if (this.hasLimitMessageTarget) {
+      this.limitMessageTarget.hidden = !atLimit
+    }
+  }
+}