possible event schema type

packages/local/test/foo.test.ts

@@ -0,0 +1,30 @@
+import { expectTypeOf, test } from "vitest";
+
+type Wrapper<T> = T extends { schema: infer S } ? S : never;
+
+export function foo<const T extends readonly { schema: unknown }[]>(
+  arr: T
+): Wrapper<T[number]>[] {
+  return arr.map((item) => item.schema) as Wrapper<T[number]>[];
+}
+
+test("infers union of schema types with literal types", () => {
+  const result = foo([{ schema: 1 }, { schema: "a" }]);
+  expectTypeOf(result).toEqualTypeOf<(1 | "a")[]>();
+});
+
+test("infers object and boolean schema types with literal types", () => {
+  const result = foo([{ schema: { x: 42 } }, { schema: true }]);
+  expectTypeOf(result).toEqualTypeOf<({ readonly x: 42 } | true)[]>();
+});
+
+test("infers single-element array with literal type", () => {
+  const result = foo([{ schema: 123 }]);
+  expectTypeOf(result).toEqualTypeOf<123[]>();
+});
+
+test("preserves literal tuple inference when using const assertions", () => {
+  const input = [{ schema: 1 }, { schema: "a" }] as const;
+  const result = foo(input);
+  expectTypeOf(result).toEqualTypeOf<(1 | "a")[]>();
+});