swc/crates/swc_ecma_parser/tests/tsc/optionalProperties01.ts

// @strictNullChecks: true
// @declaration: true

interface Foo {
  required1: string;
  required2: string;
  optional?: string;
}

const foo1 = { required1: "hello" } as Foo;
const foo2 = { required1: "hello", optional: "bar" } as Foo;