import { assertType } from "https://deno.land/x/cliffy@v1.0.0-rc.4/dev_deps.ts";
Asserts at compile time that the provided type argument's type resolves to the expected boolean literal type.
Examples
Example 1
Example 1
import { assertType, IsExact, IsNullable } from "https://deno.land/std@0.224.0/testing/types.ts";
const result = "some result" as string | number;
// compile error if the type of `result` is not exactly `string | number`
assertType<IsExact<typeof result, string | number>>(true);
// causes a compile error that `true` is not assignable to `false`
assertType<IsNullable<string>>(true); // error: string is not nullable