Deno now has https://deno.land/std/testing/snapshot.ts

Sunappu (スナップ)

Simple Snapshot Assertion in Deno using JSON.stringify

Usage

Snapshot files are saved as ES Modules with named exports in the __snapshots__ directory.

This module needs --allow-read and --allow-write runtime flag of Deno.

For snapshot updating, delete the snapshot file and regenerate it for now.

// import from deno.land/x
import { setupSnapshot } from 'https://deno.land/x/sunappu@<version>/mod.ts';

// setup Snapshot file to write/read
// argument should be always `import.meta.url`.
const assertSnapshot = await setupSnapshot(import.meta.url);

Deno.test('...', () => {
  const actual = ...

  // call the function for snapshot assertion
  // the second argument is used as the named export in the snapshot file
  assertSnapshot(actual, 'test something')
})

LICENSE

MIT