feat(webui): add user-management validation helpers

src/lib/userManagement.test.ts

@@ -0,0 +1,48 @@
+import { describe, expect, it } from "vitest";
+import {
+  isValidPassword,
+  isValidUsername,
+  otherRole,
+} from "./userManagement";
+
+describe("isValidUsername", () => {
+  it("accepts simple names", () => {
+    expect(isValidUsername("alice")).toBe(true);
+    expect(isValidUsername("A1_b-c.d")).toBe(true);
+  });
+
+  it("rejects empty and overlong names", () => {
+    expect(isValidUsername("")).toBe(false);
+    expect(isValidUsername("a".repeat(65))).toBe(false);
+  });
+
+  it("rejects names starting with a non-alphanumeric", () => {
+    expect(isValidUsername("-alice")).toBe(false);
+    expect(isValidUsername(".alice")).toBe(false);
+  });
+
+  it("rejects illegal characters", () => {
+    expect(isValidUsername("al ice")).toBe(false);
+    expect(isValidUsername("alice!")).toBe(false);
+    expect(isValidUsername("爱丽丝")).toBe(false);
+  });
+});
+
+describe("isValidPassword", () => {
+  it("requires at least 8 characters", () => {
+    expect(isValidPassword("1234567")).toBe(false);
+    expect(isValidPassword("12345678")).toBe(true);
+  });
+
+  it("rejects passwords over 256 characters", () => {
+    expect(isValidPassword("x".repeat(256))).toBe(true);
+    expect(isValidPassword("x".repeat(257))).toBe(false);
+  });
+});
+
+describe("otherRole", () => {
+  it("flips admin and user", () => {
+    expect(otherRole("admin")).toBe("user");
+    expect(otherRole("user")).toBe("admin");
+  });
+});

src/lib/userManagement.ts

@@ -0,0 +1,27 @@
+export const USERNAME_PATTERN = /^[A-Za-z0-9][A-Za-z0-9._-]{0,63}$/;
+export const PASSWORD_MIN_LENGTH = 8;
+export const PASSWORD_MAX_LENGTH = 256;
+
+export type ManagedUserRole = "admin" | "user";
+
+export interface ManagedUser {
+  username: string;
+  role: ManagedUserRole;
+  createdAt: string;
+  updatedAt: string;
+}
+
+export function isValidUsername(username: string): boolean {
+  return USERNAME_PATTERN.test(username);
+}
+
+export function isValidPassword(password: string): boolean {
+  return (
+    password.length >= PASSWORD_MIN_LENGTH &&
+    password.length <= PASSWORD_MAX_LENGTH
+  );
+}
+
+export function otherRole(role: ManagedUserRole): ManagedUserRole {
+  return role === "admin" ? "user" : "admin";
+}