Support inlining assets

lib/lego.js

@@ -43,7 +43,16 @@ module.exports = async function(args) {
       process.env.NODE_ENV = 'production';
 
       const site = new Site();
-      await runTask([...build, 'revisionAssets', ['optimiseImages', 'extractCritical', 'generateSiteMap']], site);
+      await runTask([
+        ...build,
+        'revisionAssets',
+        [
+          'optimiseImages',
+          'extractCritical',
+          'inlineAssets',
+          'generateSiteMap'
+        ]
+      ], site);
 
       site.logger.success(`Build created at ${chalk.cyan(BUILD)}.`);
     }

lib/tasks/inlineAssets.js

@@ -0,0 +1,43 @@
+module.exports = async function(site) {
+  const glob = require('glob');
+  const fs = require('fs-extra');
+  const path = require('path');
+  const { inlineSource } = require('inline-source')
+
+  const { BUILD, STATIC } = require('../utils/constants');
+
+  try {
+    let siteOptions = site.getConfig().inlineSource;
+    if (!siteOptions) {
+      return;
+    }
+
+    let message = 'Inlining Assets';
+    site.logger.await(message);
+
+    let htmlFiles = glob.sync(`${BUILD}/**/*.html`);
+    htmlFiles = htmlFiles.filter(file => !file.startsWith(`${BUILD}/${STATIC}`));
+
+    let inlineSourceOptions = Object.assign({
+      rootpath: path.resolve(BUILD),
+      // ES6 code will cause build failures if this is set as true
+      compress: false,
+      fs
+    }, siteOptions);
+
+    let inlinePromises = [];
+    for (let file of htmlFiles) {
+      let html = inlineSource(file, inlineSourceOptions);
+      inlinePromises.push(html);
+    }
+
+    let inlinedHtmlContents = await Promise.all(inlinePromises);
+    for (let [index, inlinedHtml] of inlinedHtmlContents.entries()) {
+      fs.writeFileSync(htmlFiles[index], inlinedHtml);
+    }
+
+    site.logger.success(message);
+  } catch (error) {
+    throw error;
+  }
+}

package.json

@@ -44,6 +44,7 @@
     "imagemin": "^6.0.0",
     "imagemin-mozjpeg": "^8.0.0",
     "imagemin-pngquant": "^6.0.0",
+    "inline-source": "^6.1.8",
     "liquid-node": "^3.0.0",
     "live-server": "^1.2.0",
     "markdown-it": "^8.4.2",