Add GitHub link inline macro

gems/lib/asciidoctor/foodogsquared-extensions.rb

@@ -2,6 +2,7 @@ require 'asciidoctor'
 require 'asciidoctor/extensions'
 require_relative 'man-inline-macro/extension'
 require_relative 'swhid-inline-macro/extension'
+require_relative 'github-link-inline-macro/extension'
 require_relative 'github-raw-content-include-processor/extension'
 require_relative 'gitlab-raw-content-include-processor/extension'
 require_relative 'gitlab-link-inline-macro/extension'
@@ -9,6 +10,7 @@ require_relative 'gitlab-link-inline-macro/extension'
 Asciidoctor::Extensions.register do
   inline_macro ManInlineMacro
   inline_macro SWHInlineMacro
+  inline_macro GitHubLinkInlineMacro
   include_processor GitHubRawIncludeProcessor
   include_processor GitLabRawIncludeProcessor
   inline_macro GitLabLinkInlineMacro

gems/lib/asciidoctor/github-link-inline-macro/README.adoc

@@ -0,0 +1,33 @@
+= GitHub link inline macro
+:toc:
+
+
+An inline macro that easily links repositories from GitHub.
+
+
+== Synopsis
+
+[source, asciidoc]
+----
+github:$OWNER/$REPO[$CAPTION]
+----
+
+If caption is missing, the link text will be the namespace (i.e., `$OWNER/$REPO`) of the repo.
+
+
+== Attributes
+
+There are optional attributes for this macro.
+
+- `rev` is the commit/branch/tag of the repo to be linked.
+
+- `path` is the filepath to be linked within the repo.
+
+
+== Example usage
+
+- `github:foo-dogsquared/website` will link to link:https://github.com/foo-dogsquared/website[my website repository].
+
+- `github:NixOS/nixpkgs[nixpkgs nixos-unstable branch, rev=nixos-unstable]` should link to the link:https://github.com/NixOS/nixpkgs/tree/nixos-unstable[NixOS unstable branch of nixpkgs] with a custom link text.
+
+- `github:errata-ai/vale[Vale v2.3.0 README, path=README.md, rev=v2.3.0]` should link to the link:https://github.com/errata-ai/vale/blob/v2.3.0/README.md[README of Vale v2.3.0].

gems/lib/asciidoctor/github-link-inline-macro/extension.rb

@@ -0,0 +1,23 @@
+require 'uri'
+
+class GitHubLinkInlineMacro < Asciidoctor::Extensions::InlineMacroProcessor
+  use_dsl
+
+  named :github
+  name_positional_attributes 'caption'
+
+  def process parent, target, attrs
+    doc = parent.document
+
+    text = attrs['caption'] || target
+    uri = URI.parse %(https://github.com/#{target})
+
+    uri.path += %(/tree/#{attrs['rev']}) if attrs['rev']
+    uri.path += %(/#{attrs['path']}) if attrs['path']
+
+    target = uri.to_s
+
+    doc.register :links, target
+    create_anchor parent, text, type: :link, target: target
+  end
+end