interface Runnable { isRunning: boolean; } interface Refrigerator extends Runnable { makesFoodGoBrrr: boolean; } let x: string; let y: "foo" | Refrigerator; let b: boolean; b = x === y; b = "foo" === y b = y === "foo"; b = "foo" === "bar"; b = "bar" === x; b = x === "bar"; b = y === "bar"; b = "bar" === y; b = x !== y; b = "foo" !== y b = y !== "foo"; b = "foo" !== "bar"; b = "bar" !== x; b = x !== "bar"; b = y !== "bar"; b = "bar" !== y;