Detected usage of void type outside of generic or return types JS-0333
Anti-pattern
Minor
9 days ago
—
a year old
void is not valid as a constituent in a union type
119export type ListrJob = ListrTaskObj<Context, ListrDefaultRenderer>
120
121export type MigrationJob = ListrJob & { def: JobDef }
122export type ListrTask = (ctx: Context, task: PassedTask) => Promisable<void | Listr<Context>>
Description
Disallows usage of void type outside of return types or generic type arguments. If void is used as return type, it shouldn’t be a part of intersection/union type with most other types.
Bad Practice
type PossibleValues = string | number | void;
type MorePossibleValues = string | ((number & any) | (string | void));
function logSomething(thing: void) {}
function printArg<T = void>(arg: T) {}
logAndReturn<void>(undefined);
interface Interface {
lambda: () => void;
prop: void;
}
class MyClass {
private readonly propName: void;
}
Recommended
type NoOp = () => void;
function noop(): void {}
let trulyUndefined = void 0;
async function promiseMeSomething(): Promise<void> {}
type stillVoid = void | never;