From 737e2b32325571d1dec2da461222aa995981e091 Mon Sep 17 00:00:00 2001
From: Sunil Pai <threepointone@gmail.com>
Date: Tue, 25 Jul 2017 11:46:02 +0100
Subject: [PATCH 1/2] fresh regex every time extractCritical is called

---
 src/server.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/server.js b/src/server.js
index 0a7cce7d2..dec941a6e 100644
--- a/src/server.js
+++ b/src/server.js
@@ -1,8 +1,6 @@
 import { sheet, inserted } from './index'
 import { keys, forEach } from './utils'
 
-const RGX = /css(?:[a-zA-Z0-9-]*)-([a-zA-Z0-9]+)/gm
-
 export {
   flush,
   css,
@@ -16,6 +14,8 @@ export {
 export function extractCritical (html) {
   // parse out ids from html
   // reconstruct css/rules/cache to pass
+  const RGX = /css(?:[a-zA-Z0-9-]*)-([a-zA-Z0-9]+)/gm
+  
   let o = { html, ids: [], css: '', rules: [] }
   let match
   let ids = {}

From 9a2be66507b57803f115884931e1fc9c0202e059 Mon Sep 17 00:00:00 2001
From: Kye Hohenberger <kye@sideway.com>
Date: Wed, 26 Jul 2017 22:52:52 -0600
Subject: [PATCH 2/2] Clear out the lastIndex on loop iteration.

---
 src/server.js                          |  6 ++++--
 test/__snapshots__/server.test.js.snap | 18 ++++++++++++++++++
 test/server.test.js                    | 12 +++++++++---
 3 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/src/server.js b/src/server.js
index dec941a6e..8d653b12c 100644
--- a/src/server.js
+++ b/src/server.js
@@ -15,7 +15,7 @@ export function extractCritical (html) {
   // parse out ids from html
   // reconstruct css/rules/cache to pass
   const RGX = /css(?:[a-zA-Z0-9-]*)-([a-zA-Z0-9]+)/gm
-  
+
   let o = { html, ids: [], css: '', rules: [] }
   let match
   let ids = {}
@@ -27,7 +27,9 @@ export function extractCritical (html) {
 
   o.rules = sheet.sheet.cssRules.slice().filter(x => {
     let match = RGX.exec(x.cssText)
-    return match == null || ids[match[1]] || false
+    const ret = match == null || ids[match[1]] || false
+    RGX.lastIndex = 0
+    return ret
   })
 
   o.ids = keys(inserted).filter(id => !!ids[id])
diff --git a/test/__snapshots__/server.test.js.snap b/test/__snapshots__/server.test.js.snap
index 4f5c996b9..41058727b 100644
--- a/test/__snapshots__/server.test.js.snap
+++ b/test/__snapshots__/server.test.js.snap
@@ -21,3 +21,21 @@ Object {
   ],
 }
 `;
+
+exports[`extractCritical returns static css 2`] = `
+Object {
+  "css": ".no-prefix {display:-webkit-box; display: -ms-flexbox; display: flex;-webkit-box-pack:center;-ms-flex-pack:center;justify-content:center;}.css-71uu79{display:-webkit-box; display: -ms-flexbox; display: flex;}",
+  "html": "<main class=\\"css-71uu79\\" data-reactroot=\\"\\" data-reactid=\\"1\\" data-react-checksum=\\"-1826086624\\"><div data-reactid=\\"2\\">Hello</div></main>",
+  "ids": Array [
+    "71uu79",
+  ],
+  "rules": Array [
+    Object {
+      "cssText": ".no-prefix {display:-webkit-box; display: -ms-flexbox; display: flex;-webkit-box-pack:center;-ms-flex-pack:center;justify-content:center;}",
+    },
+    Object {
+      "cssText": ".css-71uu79{display:-webkit-box; display: -ms-flexbox; display: flex;}",
+    },
+  ],
+}
+`;
diff --git a/test/server.test.js b/test/server.test.js
index 44f7ea372..7b1939967 100644
--- a/test/server.test.js
+++ b/test/server.test.js
@@ -16,7 +16,7 @@ const Image = styled.img`
   border-radius: 50%;
   height: 50px;
   width: 50px;
-  background-color: ${color}
+  background-color: ${color};
 `
 
 // this will not be included since it's not used
@@ -34,15 +34,21 @@ injectGlobal`
   }
 `
 
-const Page = () =>
+const Page1 = () =>
   <Main>
     <Image size={30} />
     <Image size={100} />
     <Image />
   </Main>
 
+const Page2 = () =>
+  <Main>
+    <div>Hello</div>
+  </Main>
+
 describe('extractCritical', () => {
   test('returns static css', () => {
-    expect(extractCritical(renderToString(<Page />))).toMatchSnapshot()
+    expect(extractCritical(renderToString(<Page1 />))).toMatchSnapshot()
+    expect(extractCritical(renderToString(<Page2 />))).toMatchSnapshot()
   })
 })