a.js(5,18): error TS1337: An index signature parameter type cannot be a literal type or generic type. Consider using a mapped object type instead.
a.js(5,28): error TS1005: ';' expected.


==== ./a.js (2 errors) ====
    /** @type {unique symbol} */
    const foo = Symbol();
    
    /** @typedef {{ [foo]: boolean }} A */
    /** @typedef {{ [key: foo] boolean }} B */
                     ~~~
!!! error TS1337: An index signature parameter type cannot be a literal type or generic type. Consider using a mapped object type instead.
                               ~~~~~~~
!!! error TS1005: ';' expected.
    