fix: add utf8 email validation support (#6239)

Co-authored-by: Thomas <thomas@ajnart.fr>

packages/validation/src/email.ts

@@ -0,0 +1,16 @@
+import { z } from "zod/v4";
+
+export const utf8EmailSchema = z.email({ pattern: z.regexes.unicodeEmail });
+
+export const optionalEmailSchema = utf8EmailSchema.or(z.string().length(0)).optional();
+
+export const nullableEmailSchema = utf8EmailSchema
+  .or(z.literal(""))
+  .transform((value) => (value === "" ? null : value))
+  .optional()
+  .nullable();
+
+export const requiredNullableEmailSchema = utf8EmailSchema
+  .or(z.literal(""))
+  .transform((value) => (value === "" ? null : value))
+  .nullable();

packages/validation/src/form/i18n.spec.ts

@@ -4,6 +4,7 @@ import { z } from "zod/v4";
 import type { TranslationFunction } from "@homarr/translation";
 
 import { createCustomErrorParams, zodErrorMap } from "./i18n";
+import { utf8EmailSchema } from "../email";
 
 const expectError = (error: z.core.$ZodIssue, key: string) => {
   expect(error.message).toContain(key);
@@ -111,4 +112,19 @@ describe("i18n", () => {
     // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
     expectError(result.error.issues[0]!, "boardAlreadyExists");
   });
+
+  test("should validate UTF8SMTP email with umlauts", () => {
+    const result = utf8EmailSchema.safeParse("jörg@example.com");
+    expect(result.success).toBe(true);
+  });
+
+  test("should validate UTF8SMTP email with unicode domain", () => {
+    const result = utf8EmailSchema.safeParse("user@münchen.de");
+    expect(result.success).toBe(true);
+  });
+
+  test("should validate standard ASCII emails", () => {
+    const result = utf8EmailSchema.safeParse("user@example.com");
+    expect(result.success).toBe(true);
+  });
 });

packages/validation/src/user.ts

@@ -6,6 +6,7 @@ import type { TranslationObject } from "@homarr/translation";
 
 import { zodEnumFromArray } from "./enums";
 import { createCustomErrorParams } from "./form/i18n";
+import { nullableEmailSchema, optionalEmailSchema } from "./email";
 
 // We always want the lowercase version of the username to compare it in a case-insensitive way
 export const usernameSchema = z.string().trim().toLowerCase().min(3).max(255);
@@ -42,7 +43,7 @@ export const userBaseCreateSchema = z.object({
   username: usernameSchema,
   password: userPasswordSchema,
   confirmPassword: z.string(),
-  email: z.string().email().or(z.string().length(0)).optional(),
+  email: optionalEmailSchema,
 });
 
 export const userCreateSchema = addConfirmPasswordRefinement(userBaseCreateSchema).and(
@@ -85,13 +86,7 @@ export const userRegistrationApiSchema = userRegistrationSchema.and(
 export const userEditProfileSchema = z.object({
   id: z.string(),
   name: usernameSchema,
-  email: z
-    .string()
-    .email()
-    .or(z.literal(""))
-    .transform((value) => (value === "" ? null : value))
-    .optional()
-    .nullable(),
+  email: nullableEmailSchema,
 });
 
 const baseChangePasswordSchema = z.object({