Skip to content

ConditionalPickDeep: Fix returning {} instead of never when no keys match #1360

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
sindresorhus merged 3 commits into from
Feb 14, 2026
+14 −4
Merged

ConditionalPickDeep: Fix returning {} instead of never when no keys match #1360

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
c521d09
`ConditionalPickDeep`: Fix returning `{}` instead of `never` when no …
derodero24 Feb 8, 2026
62fe706
`ConditionalPickDeep`: Use `expectType<never>` instead of `expectNever`
derodero24 Feb 9, 2026
a4041ad
`ConditionalPickDeep`: Use `EmptyObject` instead of `keyof` in `_Neve…
derodero24 Feb 14, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 5 additions & 3 deletions source/conditional-pick-deep.d.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -74,7 +74,7 @@ type BooleanPick = ConditionalPickDeep<Example, boolean | undefined>;
//=> {c: {e: {g?: boolean}; j: boolean}}

type NumberPick = ConditionalPickDeep<Example, number>;
//=> {}
//=> never

type StringOrBooleanPick = ConditionalPickDeep<Example, string | boolean>;
//=> {
Expand All @@ -99,11 +99,13 @@ export type ConditionalPickDeep<
Type,
Condition,
Options extends ConditionalPickDeepOptions = {},
> = _ConditionalPickDeep<
> = _NeverIfEmpty<_ConditionalPickDeep<
Type,
Condition,
ApplyDefaultOptions<ConditionalPickDeepOptions, DefaultConditionalPickDeepOptions, Options>
>;
>>;

type _NeverIfEmpty<Type> = Type extends EmptyObject ? never : Type;

type _ConditionalPickDeep<
Type,
Expand Down
10 changes: 9 additions & 1 deletion test-d/conditional-pick-deep.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -102,7 +102,15 @@ declare const emptyPick: ConditionalPickDeep<Example, 'abcdefg'>;
expectType<{never: never}>(emptyPick);

declare const emptyEqualityPick: ConditionalPickDeep<Example, 'abcdefg', {condition: 'equality'}>;
expectType<{}>(emptyEqualityPick);
expectType<never>(emptyEqualityPick);

// Returns `never` when no keys match the condition
declare const noMatchingKeys: ConditionalPickDeep<{a: string; b: number}, boolean>;
expectType<never>(noMatchingKeys);

// Union with no common properties
declare const unionNoCommon: ConditionalPickDeep<{a: string} | {b: string}, string>;
expectType<{a: string} | {b: string}>(unionNoCommon);

declare const stringOrBooleanPick: ConditionalPickDeep<Example, string | boolean>;
expectType<{
Expand Down