chore: migrate test cases from Chai to Jest

test/integration/liquid/fs-option.spec.ts

@@ -0,0 +1,52 @@
+import { Liquid } from '../../../src/liquid'
+
+describe('LiquidOptions#fs', function () {
+  let engine: Liquid
+  const fs = {
+    sep: '/',
+    dirname: (x: string) => x.split('/').slice(0, -1).join('/'),
+    exists: (x: string) => Promise.resolve(!x.match(/not-exist/)),
+    existsSync: (x: string) => !x.match(/not-exist/),
+    readFile: (x: string) => Promise.resolve(`content for ${x}`),
+    readFileSync: (x: string) => `content for ${x}`,
+    fallback: (x: string) => '/root/files/fallback',
+    resolve: (base: string, path: string) => base + '/' + path
+  }
+  beforeEach(function () {
+    engine = new Liquid({
+      root: '/root',
+      fs
+    } as any)
+  })
+  it('should be used to read templates', async function () {
+    const html = await engine.renderFile('files/foo')
+    expect(html).toBe('content for /root/files/foo')
+  })
+
+  it('should support fallback', async function () {
+    const html = await engine.renderFile('not-exist/foo')
+    expect(html).toBe('content for /root/files/fallback')
+  })
+
+  it('should support renderSync', function () {
+    const html = engine.renderFileSync('not-exist/foo')
+    expect(html).toBe('content for /root/files/fallback')
+  })
+
+  it('should throw lookup failure if fallback not specified', function () {
+    const engine = new Liquid({
+      root: '/root/',
+      fs: { ...fs, fallback: undefined }
+    } as any)
+    return expect(engine.renderFile('not-exist/foo'))
+      .rejects.toThrow('Failed to lookup')
+  })
+
+  it('should disable relativeReference if `sep` and `dirname` not specified', function () {
+    const engine = new Liquid({
+      root: '/root/',
+      fs: { ...fs, sep: undefined, dirname: undefined }
+    } as any)
+    expect(engine.options.relativeReference).toBe(false)
+  })
+})