Add html-proofer as a validation mechanism

Author: PeterJCLaw

.github/workflows/validate.yml

@@ -25,5 +25,5 @@ jobs:
         bundler-cache: true
         cache-version: 1
 
-    - name: Build
-      run: rake build
+    - name: Build & Validate
+      run: rake validate

Gemfile

@@ -9,5 +9,8 @@ gem 'kramdown-parser-gfm'
 gem 'jekyll', 3.9
 gem 'jekyll-redirect-from'
 
+# For testing output
+gem 'html-proofer'
+
 # Avoid polling on windows
 gem 'wdm', '>= 0.1.0'

Gemfile.lock

@@ -8,11 +8,21 @@ GEM
     em-websocket (0.5.2)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
+    ethon (0.15.0)
+      ffi (>= 1.15.0)
     eventmachine (1.2.7)
     eventmachine (1.2.7-x64-mingw32)
     ffi (1.15.0)
     ffi (1.15.0-x64-mingw32)
     forwardable-extended (2.6.0)
+    html-proofer (3.19.2)
+      addressable (~> 2.3)
+      mercenary (~> 0.3)
+      nokogumbo (~> 2.0)
+      parallel (~> 1.3)
+      rainbow (~> 3.0)
+      typhoeus (~> 1.3)
+      yell (~> 2.0)
     http_parser.rb (0.6.0)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
@@ -44,12 +54,23 @@ GEM
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.3.6)
+    mini_portile2 (2.6.1)
     neat (3.0.0)
       sass (~> 3.4)
       thor (~> 0.19)
+    nokogiri (1.12.5)
+      mini_portile2 (~> 2.6.1)
+      racc (~> 1.4)
+    nokogiri (1.12.5-x64-mingw32)
+      racc (~> 1.4)
+    nokogumbo (2.0.5)
+      nokogiri (~> 1.8, >= 1.8.4)
+    parallel (1.21.0)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (4.0.6)
+    racc (1.5.2)
+    rainbow (3.0.0)
     rake (12.3.3)
     rb-fsevent (0.10.4)
     rb-inotify (0.10.1)
@@ -63,13 +84,17 @@ GEM
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
     thor (0.20.3)
+    typhoeus (1.4.0)
+      ethon (>= 0.9.0)
     wdm (0.1.1)
+    yell (2.2.2)
 
 PLATFORMS
   ruby
   x64-mingw32
 
 DEPENDENCIES
+  html-proofer
   jekyll (= 3.9)
   jekyll-redirect-from
   kramdown

Rakefile

@@ -23,3 +23,15 @@ end
 task :build => [:dependencies, :submodules] do
   sh('bundle exec jekyll build --config _config.yml')
 end
+
+task :validate => [:build] do
+  # Explanation of arguments:
+  # --assume-extension  # Tells html-proofer that `.html` files can be accessed without the `.html` part in the url.
+  # --disable-external  # For speed. Ideally we'd check external links too, but ignoring for now.
+  # --empty-alt-ignore  # To avoid needing to fix lots upfront, we can migrate towards this later.
+  # --allow-hash-href   # Allow empty `#` links to mean "top of page". It's true that these can be errors, however we have far too many to really address this.
+  # --url-swap          # Adjust for Jekyll's baseurl. See https://github.com/gjtorikian/html-proofer/issues/618 for more.
+  # --url-ignore        # Allow mailto links without a target email, for our Share links. Works around https://github.com/gjtorikian/html-proofer/issues/552.
+  #                     # Allow old event links which aren't easily updated.
+  sh('bundle exec htmlproofer _site --assume-extension --disable-external --empty-alt-ignore --allow-hash-href --url-swap "^/docs/:/"')
+end