E0231: methods cannot be readonly
Class and interface methods cannot be marked as read-only. It is a syntax error
to write readonly
on a method:
class SecureFetcher {
readonly fetch() {
// ...
}
}
// TypeScript only:
interface Hasher {
readonly mix(data: string): void;
}
To fix this error, remove the readonly
keyword:
class SecureFetcher {
fetch() {
// ...
}
}
Alternatively, for TypeScript interface methods, convert the method into a field with a function type:
interface Hasher {
readonly mix: (data: string) => void;
}
Introduced in quick-lint-js version 2.6.0.