# Documentation tests Deno supports type-checking your documentation examples. This makes sure that examples within your documentation are up to date and working. The basic idea is this: ````ts /** * # Examples * * ```ts * const x = 42; * ``` */ ```` The triple backticks mark the start and end of code blocks. If this example was in a file named foo.ts, running `deno test --doc foo.ts` will extract this example, and then type-check it as a standalone module living in the same directory as the module being documented. To document your exports, import the module using a relative path specifier: ````ts /** * # Examples * * ```ts * import { foo } from "./foo.ts"; * ``` */ export function foo(): string { return "foo"; } ````