1 files changed, 86 insertions, 0 deletions
diff --git a/lib/gitlab/dependency_linker/base_linker.rb b/lib/gitlab/dependency_linker/base_linker.rb
new file mode 100644
index 00000000000..d2360583741
--- /dev/null
+++ b/lib/gitlab/dependency_linker/base_linker.rb
@@ -0,0 +1,86 @@
+module Gitlab
+  module DependencyLinker
+    class BaseLinker
+      URL_REGEX = %r{https?://[^'" ]+}.freeze
+      REPO_REGEX = %r{[^/'" ]+/[^/'" ]+}.freeze
+
+      class_attribute :file_type
+
+      def self.support?(blob_name)
+        Gitlab::FileDetector.type_of(blob_name) == file_type
+      end
+
+      def self.link(*args)
+        new(*args).link
+      end
+
+      attr_accessor :plain_text, :highlighted_text
+
+      def initialize(plain_text, highlighted_text)
+        @plain_text = plain_text
+        @highlighted_text = highlighted_text
+      end
+
+      def link
+        link_dependencies
+
+        highlighted_lines.join.html_safe
+      end
+
+      private
+
+      def link_dependencies
+        raise NotImplementedError
+      end
+
+      def license_url(name)
+        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>}
+      end
+
+      # Links package names based on regex.
+      #
+      # Example:
+      #   link_regex(/(github:|:github =>)\s*['"](?<name>[^'"]+)['"]/)
+      #   # Will link `user/repo` in `github: "user/repo"` or `:github => "user/repo"`
+      def link_regex(regex, &url_proc)
+        highlighted_lines.map!.with_index do |rich_line, i|
+          marker = StringRegexMarker.new(plain_lines[i].chomp, rich_line.html_safe)
+
+          marker.mark(regex, group: :name) do |text, left:, right:|
+            url = yield(text)
+            url ? link_tag(text, url) : text
+          end
+        end
+      end
+
+      def plain_lines
+        @plain_lines ||= plain_text.lines
+      end
+
+      def highlighted_lines
+        @highlighted_lines ||= highlighted_text.lines
+      end
+
+      def regexp_for_value(value, default: /[^'" ]+/)
+        case value
+        when Array
+          Regexp.union(value.map { |v| regexp_for_value(v, default: default) })
+        when String
+          Regexp.escape(value)
+        when Regexp
+          value
+        else
+          default
+        end
+      end
+    end
+  end
+end