fix(types): return T from Serialize when it extends undefined (#…

…2286) Co-authored-by: Daniel Roe <[email protected]>
unjs · Mar 21, 2024 · a077cb2 · a077cb2
1 parent 5184e45
commit a077cb2
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Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/src/types/serialize.ts b/src/types/serialize.ts
@@ -28,7 +28,7 @@ type FilterKeys<TObj extends object, TFilter> = {
 // prettier-ignore
 export type Serialize<T> =
  IsAny<T> extends true ? any :
- T extends JsonPrimitive ? T :
+ T extends JsonPrimitive | undefined ? T :
  T extends Map<any,any> | Set<any> ? Record<string, never> :
  T extends NonJsonPrimitive ? never :
  T extends { toJSON(): infer U } ? U :

diff --git a/test/fixture/types.ts b/test/fixture/types.ts
@@ -311,7 +311,14 @@ describe("defineCachedEventHandler", () => {
 
 describe("type helpers", () => {
  it("Serialize", () => {
+ expectTypeOf<Serialize<undefined>>().toEqualTypeOf<undefined>();
+ expectTypeOf<Serialize<{ test?: string }>>().toEqualTypeOf<{
+ test?: string;
+ }>();
  expectTypeOf<Serialize<{ test: Date }>>().toEqualTypeOf<{ test: string }>();
+ expectTypeOf<Serialize<{ test?: Date }>>().toEqualTypeOf<{
+ test?: string;
+ }>();
  expectTypeOf<Serialize<{ test: Map<string, string> }>>().toEqualTypeOf<{
  test: Record<string, never>;
  }>();