Add test for #858

sindresorhus · Apr 8, 2024 · 2547a00 · 2547a00
1 parent 7768ed6
commit 2547a00
Showing 1 changed file with 18 additions and 0 deletions.
diff --git a/test-d/override-properties.ts b/test-d/override-properties.ts
@@ -1,4 +1,5 @@
 import {expectType} from 'tsd';
+import {expectTypeOf} from 'expect-type';
 import type {OverrideProperties} from '../source/override-properties';
 
 type Foo = {
@@ -14,3 +15,20 @@ type Bar = OverrideProperties<Foo, {c: number}>;
 
 // @ts-expect-error
 type Bar = OverrideProperties<Foo, {b: number; c: number}>;
+
+// Test for https://github.com/sindresorhus/type-fest/issues/858
+{ // eslint-disable-line no-lone-blocks
+ type Original = {
+ foo: string;
+ bar: string;
+ };
+
+ type Modified = {
+ foo: string | undefined;
+ bar: string;
+ };
+
+ type Final = OverrideProperties<Original, Modified>;
+
+ expectTypeOf<Final>().toMatchTypeOf<{foo: string | undefined; bar: string}>();
+}