feat: add form validation

src/utils/handleOptionalEmptyStringToNull.ts

@@ -0,0 +1,17 @@
+export const handleOptionalEmptyStringToNull = <K>(
+  object: K,
+  required: string[] = []
+): K => {
+  return Object.fromEntries(
+    Object.entries(object).map(([key, value]) => {
+      if (
+        typeof value === 'string' &&
+        value.length === 0 &&
+        !required.includes(key)
+      ) {
+        return [key, null]
+      }
+      return [key, value]
+    })
+  ) as K
+}