refactor: remove mock-fs from dev dependency

test/stub/render.ts

@@ -0,0 +1,18 @@
+import Liquid from 'src/liquid'
+import { expect } from 'chai'
+
+export const liquid = new Liquid()
+
+export const ctx = {
+  date: new Date(),
+  foo: 'bar',
+  arr: [-2, 'a'],
+  obj: { foo: 'bar' },
+  func: function () {},
+  posts: [{ category: 'foo' }, { category: 'bar' }]
+}
+
+export async function test (src, dst) {
+  const html = await liquid.parseAndRender(src, ctx)
+  return expect(html).to.equal(dst)
+}