Autolink package names in package.json

3 files changed, 111 insertions, 0 deletions

diff --git a/lib/gitlab/dependency_linker/base_linker.rb b/lib/gitlab/dependency_linker/base_linker.rb
index 019e670081e..15fa9f40116 100644
--- a/lib/gitlab/dependency_linker/base_linker.rb
+++ b/lib/gitlab/dependency_linker/base_linker.rb
@@ -2,6 +2,7 @@ module Gitlab
   module DependencyLinker
     class BaseLinker
       URL_REGEX = %r{https?://[^'"]+}.freeze
+      REPO_REGEX = %r{[^/'"]+/[^/'"]+}.freeze
 
       class_attribute :file_type
 
@@ -36,6 +37,9 @@ module Gitlab
         Licensee::License.find(name)&.url
       end
 
+      def github_url(name)
+        "https://github.com/#{name}"
+      end
 
       def link_tag(name, url)
         %{<a href="#{ERB::Util.html_escape_once(url)}" rel="nofollow noreferrer noopener" target="_blank">#{ERB::Util.html_escape_once(name)}</a>}
diff --git a/lib/gitlab/dependency_linker/json_linker.rb b/lib/gitlab/dependency_linker/json_linker.rb
new file mode 100644
index 00000000000..021347b6429
--- /dev/null
+++ b/lib/gitlab/dependency_linker/json_linker.rb
@@ -0,0 +1,63 @@
+module Gitlab
+  module DependencyLinker
+    class JsonLinker < BaseLinker
+      def link
+        return highlighted_text unless json
+
+        super
+      end
+
+      private
+
+      # Links package names in a JSON key or values.
+      #
+      # Example:
+      #   link_json('name')
+      #   # Will link `package` in `"name": "package"`
+      #
+      #   link_json('name', 'specific_package')
+      #   # Will link `specific_package` in `"name": "specific_package"`
+      #
+      #   link_json('name', /[^\/]+\/[^\/]+/)
+      #   # Will link `user/repo` in `"name": "user/repo"`, but not `"name": "package"`
+      #
+      #   link_json('specific_package', '1.0.1', link: :key)
+      #   # Will link `specific_package` in `"specific_package": "1.0.1"`
+      def link_json(key, value = nil, link: :value, &url_proc)
+        key =
+          case key
+          when Array
+            Regexp.union(key.map { |name| Regexp.escape(name) })
+          when String
+            Regexp.escape(key)
+          when nil
+            '[^"]+'
+          else
+            key
+          end
+
+        value =
+          case value
+          when String
+            Regexp.escape(value)
+          when nil
+            '[^"]+'
+          else
+            value
+          end
+
+        if link == :value
+          value = "(?<name>#{value})"
+        else
+          key = "(?<name>#{key})"
+        end
+
+        link_regex(/"#{key}":\s*"#{value}"/, &url_proc)
+      end
+
+      def json
+        @json ||= JSON.parse(plain_text) rescue nil
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/dependency_linker/package_json_linker.rb b/lib/gitlab/dependency_linker/package_json_linker.rb
new file mode 100644
index 00000000000..330c95f0880
--- /dev/null
+++ b/lib/gitlab/dependency_linker/package_json_linker.rb
@@ -0,0 +1,44 @@
+module Gitlab
+  module DependencyLinker
+    class PackageJsonLinker < JsonLinker
+      self.file_type = :package_json
+
+      private
+
+      def link_dependencies
+        link_json('name', json["name"], &method(:package_url))
+        link_json('license', &method(:license_url))
+        link_json(%w[homepage url], URL_REGEX, &:itself)
+
+        link_packages
+      end
+
+      def link_packages
+        link_packages_at_key("dependencies", &method(:package_url))
+        link_packages_at_key("devDependencies", &method(:package_url))
+      end
+
+      def link_packages_at_key(key, &url_proc)
+        dependencies = json[key]
+        return unless dependencies
+
+        dependencies.each do |name, version|
+          link_json(name, version, link: :key, &url_proc)
+
+          link_json(name) do |value|
+            case value
+            when /\A#{URL_REGEX}\z/
+              value
+            when /\A#{REPO_REGEX}\z/
+              github_url(value)
+            end
+          end
+        end
+      end
+
+      def package_url(name)
+        "https://npmjs.com/package/#{name}"
+      end
+    end
+  end
+end