From 600b78c098bb9c1d4b6135df146e5948c1baf07f Mon Sep 17 00:00:00 2001
From: David Pike <1872727+oddnavy@users.noreply.github.com>
Date: Tue, 21 Apr 2020 22:51:16 +1000
Subject: [PATCH] fix postcss.config.js warnings (#12070)

* update postcss.config.js to fix warnings

Return empty array if the condition is not met to avoid a null/undefined PostCSS plugin.

Related PR: https://github.com/zeit/next.js/pull/11366

* style: correct linting error
---
 examples/blog-starter/postcss.config.js | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/examples/blog-starter/postcss.config.js b/examples/blog-starter/postcss.config.js
index 0daed9b0738d9..23ffee56ffe55 100644
--- a/examples/blog-starter/postcss.config.js
+++ b/examples/blog-starter/postcss.config.js
@@ -1,18 +1,21 @@
 module.exports = {
   plugins: [
     'tailwindcss',
-    process.env.NODE_ENV === 'production'
+    ...(process.env.NODE_ENV === 'production'
       ? [
-          '@fullhuman/postcss-purgecss',
-          {
-            content: [
-              './pages/**/*.{js,jsx,ts,tsx}',
-              './components/**/*.{js,jsx,ts,tsx}',
-            ],
-            defaultExtractor: content => content.match(/[\w-/:]+(?<!:)/g) || [],
-          },
+          [
+            '@fullhuman/postcss-purgecss',
+            {
+              content: [
+                './pages/**/*.{js,jsx,ts,tsx}',
+                './components/**/*.{js,jsx,ts,tsx}',
+              ],
+              defaultExtractor: content =>
+                content.match(/[\w-/:]+(?<!:)/g) || [],
+            },
+          ],
         ]
-      : undefined,
+      : []),
     'postcss-preset-env',
   ],
 }