E0230: TypeScript's 'readonly' feature is not allowed in JavaScript code
readonly on class properties is a TypeScript feature. It is a syntax error to
use readonly in JavaScript code:
class Fetcher {
readonly baseURL;
constructor(baseURL) {
this.baseURL = baseURL;
}
}
To fix this error, erase the readonly:
class Fetcher {
baseURL;
constructor(baseURL) {
this.baseURL = baseURL;
}
}
Alternatively, rename your file to have a .ts or .tsx suffix
Introduced in quick-lint-js version 2.6.0.