add failing type tests

Author: schiller-manuel

packages/react-start-client/src/tests/createServerFn.test-d.tsx

@@ -15,3 +15,39 @@ test.skip('createServerFn returns RSC', () => {
     }>
   >()
 })
+
+test('createServerFn returns async array', () => {
+  const result: Array<{ a: number }> = [{ a: 1 }]
+  const serverFn = createServerFn({ method: 'GET' }).handler(async () => {
+    return result
+  })
+
+  expectTypeOf(serverFn()).toEqualTypeOf<Promise<Array<{ a: number }>>>()
+})
+
+test('createServerFn returns sync array', () => {
+  const result: Array<{ a: number }> = [{ a: 1 }]
+  const serverFn = createServerFn({ method: 'GET' }).handler(() => {
+    return result
+  })
+
+  expectTypeOf(serverFn()).toEqualTypeOf<Promise<Array<{ a: number }>>>()
+})
+
+test('createServerFn returns async union', () => {
+  const result = '1' as string | number
+  const serverFn = createServerFn({ method: 'GET' }).handler(async () => {
+    return result
+  })
+
+  expectTypeOf(serverFn()).toEqualTypeOf<Promise<string | number>>()
+})
+
+test('createServerFn returns sync union', () => {
+  const result = '1' as string | number
+  const serverFn = createServerFn({ method: 'GET' }).handler(() => {
+    return result
+  })
+
+  expectTypeOf(serverFn()).toEqualTypeOf<Promise<string | number>>()
+})