Autolink URLs and emails in blobs and diffs

app/assets/stylesheets/highlight/dark.scss

@@ -185,6 +185,11 @@ $dark-il: #de935f;
     color: $dark-highlight-color !important;
   }
+  // Links to URLs, emails, or dependencies
+  .line a {
+    color: $dark-na;
+  }
+
   .hll { background-color: $dark-hll-bg; }
   .c { color: $dark-c; } /* Comment */
   .err { color: $dark-err; } /* Error */

app/assets/stylesheets/highlight/monokai.scss

@@ -185,6 +185,11 @@ $monokai-gi: #a6e22e;
     color: $black !important;
   }
+  // Links to URLs, emails, or dependencies
+  .line a {
+    color: $monokai-k;
+  }
+
   .hll { background-color: $monokai-hll; }
   .c { color: $monokai-c; } /* Comment */
   .err { color: $monokai-err-color; background-color: $monokai-err-bg; } /* Error */

app/assets/stylesheets/highlight/solarized_dark.scss

@@ -188,6 +188,11 @@ $solarized-dark-il: #2aa198;
     background-color: $solarized-dark-highlight !important;
   }
+  // Links to URLs, emails, or dependencies
+  .line a {
+    color: $solarized-dark-kd;
+  }
+
   /* Solarized Dark
   For use with Jekyll and Pygments

app/assets/stylesheets/highlight/solarized_light.scss

@@ -196,6 +196,11 @@ $solarized-light-il: #2aa198;
     background-color: $solarized-light-highlight !important;
   }
+  // Links to URLs, emails, or dependencies
+  .line a {
+    color: $solarized-light-kd;
+  }
+
   /* Solarized Light
   For use with Jekyll and Pygments

app/assets/stylesheets/highlight/white.scss

@@ -203,6 +203,11 @@ $white-gc-bg: #eaf2f5;
     background-color: $white-highlight !important;
   }
+  // Links to URLs, emails, or dependencies
+  .line a {
+    color: $white-nb;
+  }
+
   .hll { background-color: $white-hll-bg; }
   .c { color: $white-c; font-style: italic; }
   .err { color: $white-err; background-color: $white-err-bg; }

lib/banzai/filter/autolink_filter.rb

@@ -54,15 +54,13 @@ module Banzai
       #
       # `@doc` will be re-parsed with the HTML String from Rinku.
       def rinku_parse
-        # Convert the options from a Hash to a String that Rinku expects
-        options = tag_options(link_options)
-
         # NOTE: We don't parse email links because it will erroneously match
         # external Commit and CommitRange references.
         #
         # The final argument tells Rinku to link short URLs that don't include a
         # period (e.g., http://localhost:3000/)
-        rinku = Rinku.auto_link(html, :urls, options, IGNORE_PARENTS.to_a, 1)
+        mode = context[:autolink_emails] ? :all : :urls
+        rinku = Rinku.auto_link(html, mode, tag_options(link_options), IGNORE_PARENTS.to_a, 1)
         return if rinku == html
@@ -111,9 +109,9 @@ module Banzai
         # order to be output literally rather than escaped.
         match.gsub!(/((?:&[\w#]+;)+)\z/, '')
         dropped = ($1 || '').html_safe
-        options = link_options.merge(href: match)
-        content_tag(:a, match, options) + dropped
+        match = ERB::Util.html_escape_once(match)
+        %{<a href="#{match}" #{tag_options(link_options)}>#{match}</a>#{dropped}}.html_safe
       end
       def autolink_filter(text)

lib/banzai/pipeline/autolink_pipeline.rb

+module Banzai
+  module Pipeline
+    class AutolinkPipeline < BasePipeline
+      def self.filters
+        @filters ||= FilterArray[
+          Filter::AutolinkFilter,
+          Filter::ExternalLinkFilter
+        ]
+      end
+    end
+  end
+end

lib/gitlab/highlight.rb

@@ -21,16 +21,8 @@ module Gitlab
     end
     def highlight(text, continue: true, plain: false)
-      if plain
-        hl_lexer = Rouge::Lexers::PlainText
-        continue = false
-      else
-        hl_lexer = self.lexer
-      end
-
-      @formatter.format(hl_lexer.lex(text, continue: continue), tag: hl_lexer.tag).html_safe
-    rescue
-      @formatter.format(Rouge::Lexers::PlainText.lex(text)).html_safe
+      highlighted_text = highlight_text(text, continue: continue, plain: plain)
+      autolink_strings(highlighted_text)
     end
     def lexer
@@ -50,5 +42,41 @@ module Gitlab
       Rouge::Lexer.find_fancy(language_name)
     end
+
+    def highlight_text(text, continue: true, plain: false)
+      if plain
+        highlight_plain(text)
+      else
+        highlight_rich(text, continue: continue)
+      end
+    end
+
+    def highlight_plain(text)
+      @formatter.format(Rouge::Lexers::PlainText.lex(text)).html_safe
+    end
+
+    def highlight_rich(text, continue: true)
+      @formatter.format(lexer.lex(text, continue: continue), tag: lexer.tag).html_safe
+    rescue
+      highlight_plain(text)
+    end
+
+    def autolink_strings(highlighted_text)
+      doc = Nokogiri::HTML::DocumentFragment.parse(highlighted_text)
+
+      # Files without highlighting have all text in `span.line`.
+      # Files with highlighting have strings and comments in `span`s with a
+      # `class` starting with `c` or `s`.
+      doc.xpath('.//span[@class="line" or starts-with(@class, "c") or starts-with(@class, "s")]/text()').each do |node|
+        content = node.to_html
+        html = Banzai.render(content, pipeline: :autolink, autolink_emails: true)
+
+        next if html == content
+
+        node.replace(html)
+      end
+
+      doc.to_html.html_safe
+    end
   end
 end

spec/lib/gitlab/highlight_spec.rb

@@ -9,7 +9,7 @@ describe Gitlab::Highlight, lib: true do
   describe '.highlight_lines' do
     let(:lines) do
-      Gitlab::Highlight.highlight_lines(project.repository, commit.id, 'files/ruby/popen.rb')
+      described_class.highlight_lines(project.repository, commit.id, 'files/ruby/popen.rb')
     end
     it 'highlights all the lines properly' do
@@ -57,4 +57,69 @@ describe Gitlab::Highlight, lib: true do
       end
     end
   end
+
+  describe '#highlight' do
+    subject { described_class.highlight(file_name, file_content) }
+
+    context "plain text file" do
+      let(:file_name) { "example.txt" }
+      let(:file_content) do
+        <<-CONTENT.strip_heredoc
+          URL: http://www.google.com
+          Email: hello@example.com
+        CONTENT
+      end
+
+      it "links URLs" do
+        expect(subject).to include(%{<a href="http://www.google.com" rel="nofollow noreferrer" target="_blank">http://www.google.com</a>})
+      end
+
+      it "links emails" do
+        expect(subject).to include(%{<a href="mailto:hello@example.com">hello@example.com</a>})
+      end
+    end
+
+    context "file with highlighting" do
+      let(:file_name) { "example.rb" }
+      let(:file_content) do
+        <<-CONTENT.strip_heredoc
+          # URL in comment: http://www.google.com
+          # Email in comment: hello@example.com
+
+          "URL in string: http://www.google.com"
+          "Email in string: hello@example.com"
+
+          # <http://www.google.com>
+          # <url>http://www.google.com</url>
+        CONTENT
+      end
+
+      context "in a comment" do
+        it "links URLs" do
+          expect(subject).to include(%{URL in comment: <a href="http://www.google.com" rel="nofollow noreferrer" target="_blank">http://www.google.com</a>})
+        end
+
+        it "links emails" do
+          expect(subject).to include(%{Email in comment: <a href="mailto:hello@example.com">hello@example.com</a>})
+        end
+      end
+
+      context "in a string" do
+        it "links URLs" do
+          expect(subject).to include(%{URL in string: <a href="http://www.google.com" rel="nofollow noreferrer" target="_blank">http://www.google.com</a>})
+        end
+
+        it "links emails" do
+          expect(subject).to include(%{Email in string: <a href="mailto:hello@example.com">hello@example.com</a>})
+        end
+      end
+
+      context 'in HTML/XML tags' do
+        it "links URLs" do
+          expect(subject).to include(%{&lt;<a href="http://www.google.com" rel="nofollow noreferrer" target="_blank">http://www.google.com</a>&gt;})
+          expect(subject).to include(%{&lt;url&gt;<a href="http://www.google.com" rel="nofollow noreferrer" target="_blank">http://www.google.com</a>&lt;/url&gt;})
+        end
+      end
+    end
+  end
 end