Add an accommodations reservations module (#188)

Add a new module to enable accommodations reservation

![](https://gitea.communiquons.org/attachments/de1f5b12-0a93-40f8-b29d-97665daa6fd5)

Reviewed-on: #188

geneit_app/src/utils/form_utils.ts

@@ -0,0 +1,21 @@
+import { LenConstraint } from "../api/ServerApi";
+
+/**
+ * Check if a constraint was respected or not
+ *
+ * @returns An error message appropriate for the constraint
+ * violation, if any, or undefined otherwise
+ */
+export function checkConstraint(
+  constraint: LenConstraint,
+  value: string | undefined
+): string | undefined {
+  value = value ?? "";
+  if (value.length < constraint.min)
+    return `Veuillez indiquer au moins ${constraint.min} caractères !`;
+
+  if (value.length > constraint.max)
+    return `Veuillez indiquer au maximum ${constraint.max} caractères !`;
+
+  return undefined;
+}