import { mockFile } from "https://dotland.deno.dev/x/deno_slack_hooks@0.5.0/dev_deps.ts";
const { prepareLocalFile } = mockFile;
Preload the file that will be opened/read later.
import { prepareLocalFile } from "https://deno.land/x/mock_file@$VERSION/mod.ts";
await prepareLocalFile("./path/to/file.txt")
const file = Deno.openSync("./path/to/file.txt")