diff --git a/lib/asciidoctor/foodogsquared-extensions.rb b/lib/asciidoctor/foodogsquared-extensions.rb
index 94eda90..adb965a 100644
--- a/lib/asciidoctor/foodogsquared-extensions.rb
+++ b/lib/asciidoctor/foodogsquared-extensions.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'asciidoctor'
 require 'asciidoctor/extensions'
 require_relative 'man-inline-macro/extension'
diff --git a/lib/asciidoctor/github-link-inline-macro/extension.rb b/lib/asciidoctor/github-link-inline-macro/extension.rb
index 1c55b0c..be840c4 100644
--- a/lib/asciidoctor/github-link-inline-macro/extension.rb
+++ b/lib/asciidoctor/github-link-inline-macro/extension.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'uri'
 
 class GitHubLinkInlineMacro < Asciidoctor::Extensions::InlineMacroProcessor
@@ -6,7 +8,7 @@ class GitHubLinkInlineMacro < Asciidoctor::Extensions::InlineMacroProcessor
   named :github
   name_positional_attributes 'caption'
 
-  def process parent, target, attrs
+  def process(parent, target, attrs)
     doc = parent.document
 
     text = attrs['caption'] || target
diff --git a/lib/asciidoctor/github-raw-content-include-processor/extension.rb b/lib/asciidoctor/github-raw-content-include-processor/extension.rb
index c29ba61..20bdda8 100644
--- a/lib/asciidoctor/github-raw-content-include-processor/extension.rb
+++ b/lib/asciidoctor/github-raw-content-include-processor/extension.rb
@@ -1,14 +1,16 @@
+# frozen_string_literal: true
+
 require 'base64'
 require 'json'
 require 'open-uri'
 require 'uri'
 
 class GitHubRawIncludeProcessor < Asciidoctor::Extensions::IncludeProcessor
-  def handles? target
+  def handles?(target)
     target.start_with? 'github:'
   end
 
-  def warn_or_raise doc, warning
+  def warn_or_raise(doc, warning)
     if (doc.safe > Asciidoctor::SafeMode::SERVER) && !(doc.attr? 'allow-uri-read')
       raise warning
     else
@@ -16,7 +18,7 @@ class GitHubRawIncludeProcessor < Asciidoctor::Extensions::IncludeProcessor
     end
   end
 
-  def process doc, reader, target, attrs
+  def process(doc, reader, target, attrs)
     src = target.delete_prefix('github:').split('/', 3)
     owner = src.at 0
     repo = src.at 1
@@ -28,14 +30,14 @@ class GitHubRawIncludeProcessor < Asciidoctor::Extensions::IncludeProcessor
     uri = URI.parse %(https://api.github.com/repos/#{owner}/#{repo}/contents/#{path})
 
     if attrs['rev']
-      query = { :ref => attrs['rev'] }
+      query = { ref: attrs['rev'] }
       uri.query = URI.encode_www_form query
     end
 
     begin
       headers = {
         'Header' => 'application/vnd.github+json',
-        'X-GitHub-Api-Version' => '2022-11-28',
+        'X-GitHub-Api-Version' => '2022-11-28'
       }
 
       headers['Authorization'] = "Token #{ENV['GITHUB_API_BEARER_TOKEN']}" if ENV['GITHUB_API_BEARER_TOKEN']
@@ -45,20 +47,18 @@ class GitHubRawIncludeProcessor < Asciidoctor::Extensions::IncludeProcessor
 
         # If the response is an array, it is likely to be a directory. In this
         # usecase, we'll just list them.
-        content = if response.kind_of? Array
+        content = if response.is_a? Array
                     warning = %(given path '#{path}' from GitHub repo '#{repo}' is a directory)
                     warn_or_raise doc, warning
                     warning
-                  elsif response.kind_of? Object
-                    if response['content'] && response['encoding'] == 'base64'
-                      Base64.decode64 response['content']
-                    end
+                  elsif response.is_a? Object
+                    Base64.decode64 response['content'] if response['content'] && response['encoding'] == 'base64'
                   end
 
         reader.push_include content, target, target, 1, attrs
       end
     rescue OpenURI::HTTPError => e
-      warning = %(error while getting '#{path}' in GitHub repo '#{repo}: #{e}')
+      warning = %(error while getting '#{path}' in GitHub repo '#{namespaced_repo}: #{e}')
       warn_or_raise doc, warning
       reader.push_include warning, target, target, 1, attrs
     end
diff --git a/lib/asciidoctor/gitlab-link-inline-macro/extension.rb b/lib/asciidoctor/gitlab-link-inline-macro/extension.rb
index 37c75ab..9c84d9e 100644
--- a/lib/asciidoctor/gitlab-link-inline-macro/extension.rb
+++ b/lib/asciidoctor/gitlab-link-inline-macro/extension.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'uri'
 
 class GitLabLinkInlineMacro < Asciidoctor::Extensions::InlineMacroProcessor
@@ -7,7 +9,7 @@ class GitLabLinkInlineMacro < Asciidoctor::Extensions::InlineMacroProcessor
   name_positional_attributes 'caption'
   default_attributes 'domain' => 'gitlab.com'
 
-  def process parent, target, attrs
+  def process(parent, target, attrs)
     doc = parent.document
 
     text = attrs['caption'] || target
diff --git a/lib/asciidoctor/gitlab-raw-content-include-processor/extension.rb b/lib/asciidoctor/gitlab-raw-content-include-processor/extension.rb
index a5f0280..1214009 100644
--- a/lib/asciidoctor/gitlab-raw-content-include-processor/extension.rb
+++ b/lib/asciidoctor/gitlab-raw-content-include-processor/extension.rb
@@ -1,13 +1,15 @@
+# frozen_string_literal: true
+
 require 'base64'
 require 'json'
 require 'open-uri'
 require 'uri'
 
 class GitLabRawIncludeProcessor < Asciidoctor::Extensions::IncludeProcessor
-  @@prefix = 'gitlab:'
+  @prefix = 'gitlab:'
 
-  def handles? target
-    target.start_with? @@prefix
+  def handles?(target)
+    target.start_with? @prefix
   end
 
   def warn_or_raise doc, warning
@@ -18,14 +20,14 @@ class GitLabRawIncludeProcessor < Asciidoctor::Extensions::IncludeProcessor
     end
   end
 
-  def process doc, reader, target, attrs
-    src = target.delete_prefix(@@prefix).split('/', 2)
+  def process(doc, reader, target, attrs)
+    src = target.delete_prefix(@prefix).split('/', 2)
     owner = src.at 0
     repo = src.at 1
     namespaced_repo = "#{owner}/#{repo}"
 
-    raise %(there is no 'path' attribute given for GitLab repo '#{namespaced_repo}') unless (attrs.key? 'path')
-    raise %(no given ref for getting file in '#{namespaced_repo}') unless (attrs.key? 'rev')
+    raise %(there is no 'path' attribute given for GitLab repo '#{namespaced_repo}') unless attrs.key? 'path'
+    raise %(no given ref for getting file in '#{namespaced_repo}') unless attrs.key? 'rev'
 
     path = attrs['path']
     rev = attrs['rev']
@@ -42,7 +44,7 @@ class GitLabRawIncludeProcessor < Asciidoctor::Extensions::IncludeProcessor
     uri += %(/repository/files/#{URI.encode_www_form_component path})
 
     # Then the revision.
-    query = { :ref => rev }
+    query = { ref: rev }
     uri.query = URI.encode_www_form query
 
     content = begin
@@ -52,9 +54,7 @@ class GitLabRawIncludeProcessor < Asciidoctor::Extensions::IncludeProcessor
       OpenURI.open_uri(uri, headers) do |f|
         response = JSON.parse(f.read)
 
-        if response['content'] && response['encoding'] == 'base64'
-          Base64.decode64 response['content']
-        end
+        Base64.decode64 response['content'] if response['content'] && response['encoding'] == 'base64'
 
         reader.push_include content, target, target, 1, attrs
       end
diff --git a/lib/asciidoctor/man-inline-macro/extension.rb b/lib/asciidoctor/man-inline-macro/extension.rb
index b25a8be..8fe4142 100644
--- a/lib/asciidoctor/man-inline-macro/extension.rb
+++ b/lib/asciidoctor/man-inline-macro/extension.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ManInlineMacro < Asciidoctor::Extensions::InlineMacroProcessor
   use_dsl
 
@@ -5,7 +7,7 @@ class ManInlineMacro < Asciidoctor::Extensions::InlineMacroProcessor
   name_positional_attributes 'volnum'
   default_attributes 'domain' => 'manpages.debian.org'
 
-  def process parent, target, attrs
+  def process(parent, target, attrs)
     doc = parent.document
     text = manname = target
     suffix = (volnum = attrs['volnum']) ? %((#{volnum})) : ''
diff --git a/lib/asciidoctor/swhid-inline-macro/extension.rb b/lib/asciidoctor/swhid-inline-macro/extension.rb
index 8e3afaf..b0b4d08 100644
--- a/lib/asciidoctor/swhid-inline-macro/extension.rb
+++ b/lib/asciidoctor/swhid-inline-macro/extension.rb
@@ -1,15 +1,17 @@
+# frozen_string_literal: true
+
 class SWHInlineMacro < Asciidoctor::Extensions::InlineMacroProcessor
   use_dsl
 
   named :swh
   name_positional_attributes 'caption'
 
-  def process parent, target, attrs
+  def process(parent, target, attrs)
     doc = parent.document
 
     # We're only considering `swh:` starting with the scheme version. Also, it
     # looks nice aesthetically.
-    swhid = (target.start_with? 'swh:') ? target : %(swh:#{target})
+    swhid = target.start_with?('swh:') ? target : %(swh:#{target})
     swhid_core_identifier = (swhid.split ';').at 0
 
     text = attrs['caption'] || swhid_core_identifier