fix: birthday being undefined (#23)

* fix: birthday being undefined

* fix: add test

Author: DanielRamosAcosta

src/infrastructure/factorial-client/schema/Employee.ts

@@ -23,7 +23,7 @@ export const Employee = z.object({
   preferredName: z.string().nullable(),
   pronouns: z.string().nullable(),
   regularAccessStartsOn: z.string().nullable(),
-  showBirthday: z.boolean(),
+  showBirthday: z.boolean().optional(),
   supervisedByCurrent: z.boolean(),
   tenureStartDate: z.string().nullable(),
   terminatedOn: z.string().nullable(),

test/fixtures/employees.json

@@ -267,7 +267,6 @@
     "regularAccessStartsOn": "2019-10-04",
     "irpf": null,
     "pronouns": null,
-    "showBirthday": true,
     "permissions": {
       "hirings": {
         "read": true,