feat: improve regex

Author: jkzing

Diff for: lib/codegen/styleInjection.js

@@ -1,6 +1,6 @@
 const { attrsToQuery } = require('./utils')
 const hotReloadAPIPath = JSON.stringify(require.resolve('vue-hot-reload-api'))
-const allWhitespaceRE = /^\s+$/
+const nonWhitespaceRE = /\S+/
 
 module.exports = function genStyleInjectionCode (
   loaderContext,
@@ -71,7 +71,7 @@ module.exports = function genStyleInjectionCode (
   }
 
   // filter out empty styles (with no `src` specified or only contains whitespaces)
-  styles = styles.filter(style => style.src || !allWhitespaceRE.test(style.content))
+  styles = styles.filter(style => style.src || nonWhitespaceRE.test(style.content))
   // explicit injection is needed in SSR (for critical CSS collection)
   // or in Shadow Mode (for injection into shadow root)
   // In these modes, vue-style-loader exports objects with the __inject__