Fail the build on templating errors and undefined variables

Author: AndrewKvalheim

_config.yml

@@ -4,6 +4,10 @@ future:         false # Restore default behavior of Jekyll overridden by https:/
 timezone:       America/Los_Angeles
 markdown:       kramdown
 highlighter:    rouge
+liquid:
+    error_mode: strict
+    strict_filters: true
+    strict_variables: true
 
 # Allowed plugins: https://pages.github.com/versions/
 plugins: &plugins
@@ -36,14 +40,23 @@ collections:
         permalink: /sponsors/:path
 
 defaults:
+    - scope: { path: "" }
+      values:
+        body_id: null # Workaround for Shopify/liquid#1034
+        description: null # Workaround for Shopify/liquid#1034
+        nav: null # Workaround for Shopify/liquid#1034
     - scope: { type: archive-conferences }
       values:
         layout: archive/conference
         nav: archive
+        subtitle: null # Workaround for Shopify/liquid#1034
     - scope: { type: archive-sessions }
       values:
         layout: archive/session
         nav: archive
+        keynote: null # Workaround for Shopify/liquid#1034
+        presenters: null # Workaround for Shopify/liquid#1034
+        resources: null # Workaround for Shopify/liquid#1034
     - scope: { type: sponsor-years }
       values:
         body_id: sponsors

_layouts/archive/conference.html

@@ -9,7 +9,7 @@
   | where_exp: 'session', 'session.relative_path contains path_prefix'
   | sort: 'beginning'
   | group_by_exp: 'session', 'session.beginning | date: "%A"' %}
-{% assign posts = site.tags[year] | where: 'categories','news' | reverse %}
+{% if site.tags contains year %}{% assign posts = site.tags[year] | where: 'categories','news' | reverse %}{% else %}{% assign posts = empty %}{% endif %}
 
 <div class="row">
   <div class="col-xs-12 col-lg-10 col-lg-push-1">
@@ -41,7 +41,7 @@ <h2>{{ day.name }}</h2>
 
             {% for presenter in session.presenters %}
             <div>
-              {{ presenter.name }}{% if presenter.affiliation %}<span class="text-muted">, {{ presenter.affiliation }}</span>{% endif %}
+              {{ presenter.name }}{% if presenter contains 'affiliation' %}<span class="text-muted">, {{ presenter.affiliation }}</span>{% endif %}
             </div>
             {% endfor %}
           </li>

_layouts/archive/session.html

@@ -8,7 +8,7 @@
 <div class="row">
   <div class="col-xs-12 col-lg-10 col-lg-push-1">
     {% if session.resources %}
-    {% if session.resources.internet_archive_identifier %}
+    {% if session.resources contains 'internet_archive_identifier' %}
     <figure>
       <div class="embed-responsive embed-responsive-16by9">
         <iframe class="embed-responsive-item" src="https://archive.org/embed/{{ session.resources.internet_archive_identifier }}" allowfullscreen mozallowfullscreen="true" webkitallowfullscreen="true"></iframe>
@@ -19,7 +19,7 @@
         If you value their service, please consider thanking them with a small donation.
       </figcaption>
     </figure>
-    {% elsif session.resources.youtube_id %}
+    {% elsif session.resources contains 'youtube_id' %}
     <figure>
       <div class="embed-responsive embed-responsive-16by9">
         <div class="embed-responsive-item embed-placeholder">
@@ -58,11 +58,11 @@ <h3>Presenters</h3>
         {% for presenter in session.presenters %}
         <div class="media">
           <div class="media-left">
-            <img class="img-circle" width="64" height="64" alt="{{ presenter.name }}" src="https://s.gravatar.com/avatar/{{ presenter.gravatar_id }}?d=mp&s=128">
+            <img class="img-circle" width="64" height="64" alt="{{ presenter.name }}" src="https://s.gravatar.com/avatar/{% if presenter contains 'gravatar_id' %}{{ presenter.gravatar_id }}{% endif %}?d=mp&s=128">
           </div>
           <div class="media-body media-middle">
-            <h4 class="media-heading">{{ presenter.name }}{% if presenter.pronouns %}<span class="text-muted"> ({{ presenter.pronouns }})</span>{% endif %}{% if presenter.affiliation %}<span class="text-muted">, {{ presenter.affiliation }}</span>{% endif %}</h4>
-            {{ presenter.biography | markdownify }}
+            <h4 class="media-heading">{{ presenter.name }}{% if presenter contains 'pronouns' %}<span class="text-muted"> ({{ presenter.pronouns }})</span>{% endif %}{% if presenter contains 'affiliation' %}<span class="text-muted">, {{ presenter.affiliation }}</span>{% endif %}</h4>
+            {% if presenter contains 'biography' %}{{ presenter.biography | markdownify }}{% endif %}
           </div>
         </div>
         {% endfor %}
@@ -72,21 +72,21 @@ <h4 class="media-heading">{{ presenter.name }}{% if presenter.pronouns %}<span c
         <h3>Resources</h3>
 
         <ul>
-          {% if session.resources.resources_url %}
+          {% if session.resources contains 'resources_url' %}
           <li><a href="{{ session.resources.resources_url }}">Resources</a></li>
           {% endif %}
 
-          {% if session.resources.slides_url %}
+          {% if session.resources contains 'slides_url' %}
           <li><a href="{{ session.resources.slides_url }}">Slides</a></li>
           {% endif %}
 
-          {% if session.resources.internet_archive_identifier %}
+          {% if session.resources contains 'internet_archive_identifier' %}
           <li><a href="https://archive.org/details/{{ session.resources.internet_archive_identifier }}">Video Recording</a></li>
-          {% elsif session.resources.youtube_id %}
+          {% elsif session.resources contains 'youtube_id' %}
           <li><a href="https://youtu.be/{{ session.resources.youtube_id }}">Video Recording</a></li>
           {% endif %}
 
-          {% if session.resources.audio_url %}
+          {% if session.resources contains 'audio_url' %}
           <li><a href="{{ session.resources.audio_url }}">Audio Recording</a></li>
           {% endif %}
         </ul>

_layouts/post.html

@@ -13,13 +13,13 @@
 
     <div class="row">
       <div class="col-md-6">
-        {% if page.previous.url %}
+        {% if page.previous %}
           <a class="prev" href="{{page.previous.url}}">&laquo; {{page.previous.title}}</a>
         {% endif %}
       </div>
 
       <div class="col-md-6 text-right">
-        {% if page.next.url %}
+        {% if page.next %}
           <a class="next" href="{{page.next.url}}">{{page.next.title}} &raquo;</a>
         {% endif %}
       </div>