Repository navigation
Better error messages for converting symbols to strings #25870
Description
Starting
declare let x: symbol;
// [ts] Type 'symbol' cannot be converted to type 'string'.
`${x}`;
// [ts] The '+' operator cannot be applied to type 'symbol'.
"" + x;I believe with TypeScript 2.9, we started erroring on the former operation (#22251). When upgrading to 2.9 with Yehuda Katz (@wycats), we got these error messages and it became clear that for most users it wouldn't immediately be obvious why this was an error.
Yehuda Katz (@wycats) had the recommendation that we suggest using String(x):
Type 'symbol' cannot be converted to type 'string'. Consider wrapping this expression in 'String(...)'.
Activity
mhegazy commentedon Jul 23, 2018
Related to the change in #25541
Improve the error message when asserting to a type that is not
Improve the error message when asserting to a type that is not
DanielRosenwasser commentedon Jul 26, 2018
Thanks Matt McCutchen (@mattmccutchen)!