fix(mysql): improve create database permission hint

apps/desktop/src/lib/__tests__/database/createDatabaseErrorHints.spec.ts

@@ -0,0 +1,31 @@
+import { describe, expect, it } from "vitest";
+import { appendCreateDatabaseErrorHint } from "@/lib/database/createDatabaseErrorHints";
+
+const hint = "Use an account with GRANT OPTION to grant CREATE permission.";
+const t = (key: string) => (key === "contextMenu.mysqlCreateDatabasePermissionHint" ? hint : key);
+
+describe("appendCreateDatabaseErrorHint", () => {
+  it("adds guidance for MySQL error 1044", () => {
+    const message = appendCreateDatabaseErrorHint("mysql", "ERROR 1044 (42000): Access denied for user 'root'@'%' to database 'pro'", t);
+
+    expect(message).toContain("ERROR 1044");
+    expect(message).toContain(hint);
+  });
+
+  it("recognizes access-denied messages when the driver omits the error code", () => {
+    const message = appendCreateDatabaseErrorHint("mysql", "Access denied for user 'app'@'%' to database 'pro'", t);
+
+    expect(message).toContain(hint);
+  });
+
+  it("does not alter unrelated or non-MySQL errors", () => {
+    expect(appendCreateDatabaseErrorHint("mysql", "ERROR 1007: Can't create database; database exists", t)).toBe("ERROR 1007: Can't create database; database exists");
+    expect(appendCreateDatabaseErrorHint("postgres", "ERROR 1044: permission denied", t)).toBe("ERROR 1044: permission denied");
+  });
+
+  it("does not append the same hint twice", () => {
+    const original = `ERROR 1044: Access denied\n\n${hint}`;
+
+    expect(appendCreateDatabaseErrorHint("mysql", original, t)).toBe(original);
+  });
+});

apps/desktop/src/lib/database/createDatabaseErrorHints.ts

@@ -0,0 +1,13 @@
+import type { DatabaseType } from "@/types/database";
+
+type Translate = (key: string) => string;
+
+function isMysqlCreateDatabaseAccessDenied(message: string): boolean {
+  return /\b1044\b/i.test(message) || /access denied for user[\s\S]*to database/i.test(message);
+}
+
+export function appendCreateDatabaseErrorHint(databaseType: DatabaseType | undefined, message: string, t: Translate): string {
+  if (databaseType !== "mysql" || !isMysqlCreateDatabaseAccessDenied(message)) return message;
+  const hint = t("contextMenu.mysqlCreateDatabasePermissionHint");
+  return message.includes(hint) ? message : `${message}\n\n${hint}`;
+}