alphagov · mrwilson · May 17, 2023 · Mar 31, 2022 · Mar 31, 2022 · Mar 31, 2022
diff --git a/Gemfile b/Gemfile
@@ -11,3 +11,5 @@ gem 'tzinfo-data', platforms: [:mswin, :mingw, :jruby]
 # Include the tech docs gem
 gem 'govuk_tech_docs'
 
+# Include linter to check for dead internal links
+gem 'html-proofer', '~> 3.19.4'
diff --git a/Gemfile.lock b/Gemfile.lock
@@ -37,6 +37,8 @@ GEM
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0)
     erubis (2.7.0)
+    ethon (0.16.0)
+      ffi (>= 1.15.0)
     eventmachine (1.2.7)
     execjs (2.8.1)
     fast_blank (1.0.1)
@@ -61,6 +63,14 @@ GEM
     hamster (3.0.0)
       concurrent-ruby (~> 1.0)
     hashie (3.6.0)
+    html-proofer (3.19.4)
+      addressable (~> 2.3)
+      mercenary (~> 0.3)
+      nokogiri (~> 1.13)
+      parallel (~> 1.10)
+      rainbow (~> 3.0)
+      typhoeus (~> 1.3)
+      yell (~> 2.0)
     http_parser.rb (0.8.0)
     i18n (0.9.5)
       concurrent-ruby (~> 1.0)
@@ -70,6 +80,7 @@ GEM
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
     memoist (0.16.2)
+    mercenary (0.4.0)
     middleman (4.3.11)
       coffee-script (~> 2.2)
       haml (>= 4.0.5)
@@ -141,6 +152,7 @@ GEM
     rack (2.2.6.4)
     rack-livereload (0.3.17)
       rack
+    rainbow (3.1.1)
     rb-fsevent (0.11.2)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
@@ -156,17 +168,23 @@ GEM
       rack (>= 2.2.4, < 4)
     temple (0.10.0)
     thor (1.2.1)
-    thread_safe (0.3.6)
     tilt (2.0.11)
-    tzinfo (1.2.10)
-      thread_safe (~> 0.1)
+    typhoeus (1.4.0)
+      ethon (>= 0.9.0)
+    tzinfo (2.0.6)
+      concurrent-ruby (~> 1.0)
     uglifier (3.2.0)
       execjs (>= 0.3.0, < 3)
+    yell (2.2.2)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   govuk_tech_docs
+  html-proofer (~> 3.19.4)
   tzinfo-data
   wdm (~> 0.1.0)
+
+BUNDLED WITH
+   2.1.4
diff --git a/config.rb b/config.rb
@@ -1,5 +1,31 @@
 require 'govuk_tech_docs'
 
+# Check for broken links
+require 'html-proofer'
+
 GovukTechDocs.configure(self)
 
 set :layout, 'custom'
+
+after_build do |builder|
+  begin
+    proofer = HTMLProofer.check_directory(config[:build_dir],
+      { :assume_extension => true,
+        :allow_hash_href => true,
+        :check_internal_hash => true,
+        :empty_alt_ignore => true,
+        :file_ignore => [
+            /search/ # Provided by tech-docs gem but has a "broken" link from html-proofer's point of view
+        ],
+        :url_ignore => [
+            "https://gdshelpdesk.digital.cabinet-office.gov.uk",
+            "https://gds-way.cloudapps.digital/standards/secrets-acl.html",
+            /https:\/\/github.com\//
+        ]
+      })
+
+      proofer.run
+  rescue RuntimeError => e
+    abort e.to_s
+  end
+end
diff --git a/config/tech-docs.yml b/config/tech-docs.yml
@@ -36,8 +36,7 @@ default_owner_slack: '#gds-way'
 owner_slack_workspace: gds
 
 redirects:
-  /standards/publish-opensource-code.html: /standards/source-code/#publish-open-source-code
-  /standards/git.html: /standards/source-code/#working-with-git
-  /standards/source-code.html: /standards/source-code/
+  /standards/publish-opensource-code.html: /standards/source-code/index.html#publish-open-source-code
+  /standards/git.html: /standards/source-code/working-with-git.html
   /standards/testing-with-rspec.html: /manuals/programming-languages/ruby.html#testing-with-rspec
   /standards/secrets-ACL.html: /standards/secrets-acl.html
diff --git a/source/manuals/programming-languages/java.html.md.erb b/source/manuals/programming-languages/java.html.md.erb
@@ -199,7 +199,7 @@ If you are starting a new Java project, do not use anything older than the lates
 
 If you are currently using an older LTS version of Java, you should be planning to upgrade to something newer. Different Java vendors have different support lifecycles for different Java releases.
 
-Recent versions of the [Oracle JDK can be used free of charge](https://blogs.oracle.com/java/post/free-java-license) for commercial and production purposes under the terms of a bespoke licence. OpenJDK is open source under the [GPLv2 with the Classpath Exception](https://openjdk.java.net/legal/gplv2+ce.html) but Oracle only provide general-availability [OpenJDK builds](https://jdk.java.net/) for the latest release.
+Recent versions of the [Oracle JDK can be used free of charge](https://www.oracle.com/downloads/licenses/no-fee-license.html) for commercial and production purposes under the terms of a bespoke licence. OpenJDK is open source under the [GPLv2 with the Classpath Exception](https://openjdk.java.net/legal/gplv2+ce.html) but Oracle only provide general-availability [OpenJDK builds](https://jdk.java.net/) for the latest release.
 
 The [Adoptium](https://adoptium.net/) (formerly AdoptOpenJDK) project (part of the [Eclipse Foundation](https://www.eclipse.org/)) provides fully open-source TCK-certified pre-built OpenJDK binaries under the name Eclipse Temurin. For LTS releases (such as Java 8, 11 and 17), Adoptium have committed to releasing free updates for several years.
 

diff --git a/source/manuals/programming-languages/nodejs/index.html.md.erb b/source/manuals/programming-languages/nodejs/index.html.md.erb
@@ -20,9 +20,6 @@ the main [programming languages manual page](../../programming-languages.html).
 The advice here is specifically about Node.js. Generic guidelines on writing
 code are out of scope.
 
-If you want to contribute to this document please see the [Updating this
-manual](#updating-this-manual) section below.
-
 Most guidelines listed here are recommendations, and the authors acknowledge
 that there will sometimes be valid exceptions.
 

diff --git a/source/manuals/programming-languages/ruby.html.md.erb b/source/manuals/programming-languages/ruby.html.md.erb
@@ -33,6 +33,8 @@ applications we have chosen [Sinatra] before - however this
 should be approached with caution as these can easily become large applications
 over time that are less conventionally organised than Rails applications.
 
+## Testing with RSpec
+
 For testing, the [RSpec] framework is the conventional and preferred choice.
 RSpec provides an expressive syntax that lends itself to producing readable
 tests. For testing functionality from a user's perspective it is preferred

diff --git a/source/partials/_nav-version-control-deployments.html.erb b/source/partials/_nav-version-control-deployments.html.erb
@@ -1,5 +1,5 @@
 <ul>
-  <li><a href="/standards/source-code/">How to store source code</a></li>
+  <li><a href="/standards/source-code/index.html">How to store source code</a></li>
   <li><a href="/standards/pull-requests.html">Using Pull Requests</a></li>
   <li><a href="/manuals/readme-guidance.html">Writing READMEs</a></li>
   <li><a href="/manuals/release-notes.html">Writing release notes</a></li>

diff --git a/source/standards/continuous-delivery.html.md.erb b/source/standards/continuous-delivery.html.md.erb
@@ -64,7 +64,7 @@ Find out more about continuous delivery from:
 - [Trunk Based Development][] - a source control branching method
 
 [Continuous delivery]: https://www.continuousdelivery.com
-[feature-flagging]: https://featureflags.io/2016/10/28/continuous-delivery-coding-patterns-feature-toggles/
+[feature-flagging]: https://martinfowler.com/articles/feature-toggles.html
 [modular architectures]: https://continuousdelivery.com/implementing/architecture/
 [production monitoring and alerting]: https://gds-way.cloudapps.digital/standards/monitoring.html
 [Pull Requests]: https://gds-way.cloudapps.digital/standards/pull-requests.html

diff --git a/source/standards/optimise-frontend-perf.html.md.erb b/source/standards/optimise-frontend-perf.html.md.erb
@@ -96,7 +96,7 @@ You can find out more about improving your website’s frontend performance by r
 The Service Manual has more suggestions about [how you can test frontend performance][].
 
 [frontend performance]: https://www.gov.uk/service-manual/technology/how-to-test-frontend-performance
-[minification]: https://minifycode.com/
+[minification]: https://web.dev/reduce-network-payloads-using-text-compression/
 [Gzip]: https://web.dev/optimizing-content-efficiency-optimize-encoding-and-transfer/#text_compression_with_gzip
 [Cache-Control]: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control
 [ETag]: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag

diff --git a/source/standards/principle-least-access.html.md.erb b/source/standards/principle-least-access.html.md.erb
@@ -45,4 +45,4 @@ If you’re using the gds-users account to log into your AWS accounts, you shoul
 - [NCSC - privileged user management](https://www.ncsc.gov.uk/guidance/introduction-identity-and-access-management#section_6)
 - [NIST Special Publication 800-53 - AC-6 least privilege][polp]
 
-[polp]: https://csrc.nist.gov/Projects/risk-management/sp800-53-controls/release-search#!/control?version=5.1&number=AC-6
+[polp]: https://csrc.nist.gov/Projects/risk-management/sp800-53-controls/release-search
diff --git a/source/standards/pull-requests.html.md.erb b/source/standards/pull-requests.html.md.erb
@@ -144,5 +144,5 @@ You should add a documentation credit thanking the contributor if you do not add
 [good-pr]: https://github.com/alphagov/frontend/pull/784
 [alice]: https://github.com/alicebartlett
 [style-enf]: https://technology.blog.gov.uk/2016/09/30/easing-the-process-of-pull-request-reviews/
-[paul]: https://twitter.com/boffbowsh
+[paul]: https://mastodon.me.uk/@boffbowsh
 [prs]: https://docs.github.com/en/github/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/about-pull-requests