Reduce the external files required for gem installation

assets/404.html

@@ -0,0 +1,21 @@
+---
+layout: page
+title: "404: Page not found"
+permalink: /404.html
+
+redirect_from:
+  - /norobots/
+  - /assets/
+  - /posts/
+
+dynamic_title: true
+---
+
+<div class="lead">
+  <p>Sorry, we've misplaced that URL or it's pointing to something that doesn't exist. </p>
+  <p>
+    <a href="{{ '/' | relative_url }}">Head back Home</a>
+    to try finding it again, or search for it on the
+    <a href="{{ 'archives' | relative_url }}">Archives page</a>.
+  </p>
+</div>

assets/feed.xml

@@ -0,0 +1,61 @@
+---
+layout: compress
+permalink: /feed.xml
+# Atom Feed, reference: https://validator.w3.org/feed/docs/atom.html
+---
+
+{% capture source %}
+<feed xmlns="http://www.w3.org/2005/Atom">
+  <id>{{ "/" | absolute_url }}</id>
+  <title>{{ site.title }}</title>
+  <subtitle>{{ site.description }}</subtitle>
+  <updated>{{ site.time | date_to_xmlschema }}</updated>
+  <author>
+    <name>{{ site.social.name }}</name>
+    <uri>{{ "/" | absolute_url }}</uri>
+  </author>
+  <link rel="self" type="application/atom+xml" href="{{ page.url | absolute_url }}"/>
+  <link rel="alternate" type="text/html" hreflang="{{ site.lang | default: 'en' }}"
+    href="{{ '/' | absolute_url }}"/>
+  <generator uri="https://jekyllrb.com/" version="{{ jekyll.version }}">Jekyll</generator>
+  <rights> © {{ 'now' | date: '%Y' }} {{ site.social.name }} </rights>
+  <icon>{{ site.baseurl }}/assets/img/favicons/favicon.ico</icon>
+  <logo>{{ site.baseurl }}/assets/img/favicons/favicon-96x96.png</logo>
+
+{% for post in site.posts limit: 5 %}
+  {% assign post_absolute_url = post.url | absolute_url %}
+  <entry>
+    <title>{{ post.title }}</title>
+    <link href="{{ post_absolute_url }}" rel="alternate" type="text/html" title="{{ post.title }}" />
+    <published>{{ post.date | date_to_xmlschema }}</published>
+  {% if post.last_modified_at %}
+    <updated>{{ post.last_modified_at | date_to_xmlschema }}</updated>
+  {% else %}
+    <updated>{{ post.date | date_to_xmlschema }}</updated>
+  {% endif %}
+    <id>{{ post_absolute_url }}</id>
+    <content src="{{ post_absolute_url }}" />
+    <author>
+      <name>{{ post.author | default: site.social.name }}</name>
+    </author>
+
+  {% if post.categories %}
+    {% for category in post.categories %}
+    <category term="{{ category }}" />
+    {% endfor %}
+  {% endif %}
+
+  {% if post.summary %}
+    <summary>{{ post.summary | strip }}</summary>
+  {% else %}
+    <summary>
+      {% include no-linenos.html content=post.content %}
+      {{ content  | strip_html | truncate: 400 }}
+    </summary>
+  {% endif %}
+
+  </entry>
+{% endfor %}
+</feed>
+{% endcapture %}
+{{ source | replace: '&', '&amp;' }}

assets/js/pwa/app.js

@@ -0,0 +1,9 @@
+---
+layout: compress
+permalink: '/app.js'
+---
+
+/* Registering Service Worker */
+if('serviceWorker' in navigator) {
+  navigator.serviceWorker.register('{{ "/sw.js" | relative_url }}');
+};

assets/js/pwa/sw.js

@@ -0,0 +1,87 @@
+---
+layout: compress
+permalink: '/sw.js'
+# PWA service worker
+---
+
+self.importScripts('{{ "/assets/js/data/swcache.js" | relative_url }}');
+
+const cacheName = 'chirpy-{{ "now" | date: "%Y%m%d.%H%M" }}';
+
+function verifyDomain(url) {
+  for (const domain of allowedDomains) {
+    const regex = RegExp(`^http(s)?:\/\/${domain}\/`);
+    if (regex.test(url)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+function isExcluded(url) {
+  for (const item of denyUrls) {
+    if (url === item) {
+      return true;
+    }
+  }
+  return false;
+}
+
+self.addEventListener('install', e => {
+  self.skipWaiting();
+  e.waitUntil(
+    caches.open(cacheName).then(cache => {
+      return cache.addAll(resource);
+    })
+  );
+});
+
+self.addEventListener('fetch', event => {
+  event.respondWith(
+    caches.match(event.request)
+      .then(response => {
+        if (response) {
+          return response;
+        }
+
+        return fetch(event.request)
+          .then(response => {
+            const url = event.request.url;
+
+            if (event.request.method !== 'GET' ||
+              !verifyDomain(url) ||
+              isExcluded(url)) {
+              return response;
+            }
+
+            /*
+              see: <https://developers.google.com/web/fundamentals/primers/service-workers#cache_and_return_requests>
+             */
+            let responseToCache = response.clone();
+
+            caches.open(cacheName)
+              .then(cache => {
+                /* console.log('[sw] Caching new resource: ' + event.request.url); */
+                cache.put(event.request, responseToCache);
+              });
+
+            return response;
+          });
+      })
+    );
+});
+
+self.addEventListener('activate', e => {
+  e.waitUntil(
+    caches.keys().then(keyList => {
+          return Promise.all(
+            keyList.map(key => {
+              if(key !== cacheName) {
+                return caches.delete(key);
+              }
+            })
+          );
+    })
+  );
+});

assets/robots.txt

@@ -0,0 +1,10 @@
+---
+permalink: /robots.txt
+# The robots rules
+---
+
+User-agent: *
+
+Disallow: /norobots/
+
+Sitemap: {{ '/sitemap.xml' | absolute_url }}