fix(icon): generate only on build

Author: Pooya Parsa

Diff for: packages/icon/index.js

@@ -1,11 +1,19 @@
 const fs = require('fs-extra')
 const path = require('path')
 const Jimp = require('jimp')
+const debug = require('debug')('nuxt:pwa:icon')
 
 const fixUrl = url => url.replace(/\/\//g, '/').replace(':/', '://')
 const isUrl = url => url.indexOf('http') === 0 || url.indexOf('//') === 0
 
 module.exports = function nuxtIcon (options) {
+  this.nuxt.plugin('build', builder => {
+    debug('Generating icons')
+    generateIcons.call(this, options)
+  })
+}
+
+function generateIcons (options) {
   const iconSrc = options.iconSrc || path.resolve(this.options.srcDir, 'static', 'icon.png')
   const sizes = options.sizes || [64, 120, 144, 152, 192, 384, 512]
 
@@ -22,7 +30,7 @@ module.exports = function nuxtIcon (options) {
   // Ensure icon file exists
   if (!fs.existsSync(iconSrc)) {
     /* eslint-disable no-console */
-    console.warn('[@nuxtjs/icon]', path.relative(this.options.srcDir, iconSrc), 'not found! Please create one or disable icon module.')
+    debug(path.relative(this.options.srcDir, iconSrc), 'not found! Please create one or disable icon module.')
     return
   }