From 310e98d5ba0fd95d5d7a7b5b0e6c55e94bf4c783 Mon Sep 17 00:00:00 2001
From: JJ Kasper <jj@jjsweb.site>
Date: Thu, 6 Feb 2020 21:36:56 -0600
Subject: [PATCH] Add test for data preload link

---
 test/integration/prerender/test/index.test.js | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/test/integration/prerender/test/index.test.js b/test/integration/prerender/test/index.test.js
index a1bad06c53b7c..8a3014c483e3b 100644
--- a/test/integration/prerender/test/index.test.js
+++ b/test/integration/prerender/test/index.test.js
@@ -255,13 +255,16 @@ const runTests = (dev = false) => {
     const html = await renderViaHTTP(appPort, '/blog/post-1')
 
     if (dev) {
-      expect(
-        JSON.parse(
-          cheerio
-            .load(html)('#__NEXT_DATA__')
-            .text()
-        ).isFallback
-      ).toBe(true)
+      const $ = cheerio.load(html)
+      expect(JSON.parse($('#__NEXT_DATA__').text()).isFallback).toBe(true)
+
+      const preloadLink = Array.from($('link[rel=preload]')).find(el =>
+        el.attribs.href.endsWith('post-1.json')
+      )
+
+      expect(preloadLink.attribs.href).toBe(
+        `/_next/data/${buildId}/blog/post-1.json`
+      )
     } else {
       expect(html).toMatch(/Post:.*?post-1/)
     }