OptionalstrictConsider never elements to match the target type only if the target type itself is never (or any).
true (default), never is not treated as a bottom type, instead, it is treated as a type that matches only itself (or any).false, never is treated as a bottom type, and behaves as it normally would.import type {SomeExtend} from 'type-fest';
type A = SomeExtend<[1, 2, never], string, {strictNever: true}>;
//=> false
type B = SomeExtend<[1, 2, never], string, {strictNever: false}>;
//=> true
type C = SomeExtend<[1, never], never, {strictNever: true}>;
//=> true
type D = SomeExtend<[1, never], never, {strictNever: false}>;
//=> true
type E = SomeExtend<[never], any, {strictNever: true}>;
//=> true
type F = SomeExtend<[never], any, {strictNever: false}>;
//=> true
See
SomeExtend