Enable CommonMark alert extension (#42603).

Patch by Mizuki ISHIKAWA (user:ishikawa999).

git-svn-id: https://svn.redmine.org/redmine/trunk@23724 e93f8b46-1217-0410-a6f0-8f06a7374b81

5 files changed, 127 insertions, 9 deletions

diff --git a/app/assets/stylesheets/application.css b/app/assets/stylesheets/application.css
index 7dc1a64b4..c63a89a75 100644
--- a/app/assets/stylesheets/application.css
+++ b/app/assets/stylesheets/application.css
@@ -1262,6 +1262,38 @@ div.flash.warning svg.icon-svg, .conflict svg.icon-svg {
 
 .conflict-details {font-size:93%;}
 
+/***** CommonMark Alerts *****/
+.markdown-alert {
+  border-left: 4px solid;
+  padding: 10px 10px 1px 10px;
+  margin: 10px 0;
+}
+
+.markdown-alert-title + p {
+  margin-top: 2px;
+}
+
+.markdown-alert-title {
+  font-weight: bold;
+  margin-bottom: 0.5em;
+  margin: 0;
+}
+
+.markdown-alert-tip { border-color: #5db651; }
+.markdown-alert-tip .markdown-alert-title { color: #005f00; }
+
+.markdown-alert-important { border-color: #800080; }
+.markdown-alert-important .markdown-alert-title { color: #4b006e; }
+
+.markdown-alert-caution { border-color: #c22; }
+.markdown-alert-caution .markdown-alert-title { color: #880000; }
+
+.markdown-alert-warning { border-color: #e4bc4b; }
+.markdown-alert-warning .markdown-alert-title { color: #a7760c; }
+
+.markdown-alert-note { border-color: #169; }
+.markdown-alert-note .markdown-alert-title { color: #1e40af; }
+
 /***** Ajax indicator ******/
 #ajax-indicator {
 position: absolute; /* fixed not supported by IE */
diff --git a/lib/redmine/wiki_formatting/common_mark/formatter.rb b/lib/redmine/wiki_formatting/common_mark/formatter.rb
index b695fb854..f2b9bca04 100644
--- a/lib/redmine/wiki_formatting/common_mark/formatter.rb
+++ b/lib/redmine/wiki_formatting/common_mark/formatter.rb
@@ -34,6 +34,7 @@ module Redmine
           header_ids: nil,
           tasklist: true,
           shortcodes: false,
+          alerts: true,
         }.freeze,
 
         # https://github.com/gjtorikian/commonmarker#parse-options
diff --git a/lib/redmine/wiki_formatting/common_mark/sanitization_filter.rb b/lib/redmine/wiki_formatting/common_mark/sanitization_filter.rb
index e603d9f7f..584df9e0d 100644
--- a/lib/redmine/wiki_formatting/common_mark/sanitization_filter.rb
+++ b/lib/redmine/wiki_formatting/common_mark/sanitization_filter.rb
@@ -68,6 +68,26 @@ module Redmine
             end
           }
 
+          # Allow class on div and p tags only for alert blocks
+          # (must be exactly: "markdown-alert markdown-alert-*" for div, and "markdown-alert-title" for p)
+          (allowlist[:attributes]["div"] ||= []) << "class"
+          (allowlist[:attributes]["p"] ||= []) << "class"
+          allowlist[:transformers].push lambda{|env|
+            node = env[:node]
+            return unless node.element?
+
+            case node.name
+            when 'div'
+              unless node['class'] =~ /\Amarkdown-alert markdown-alert-[a-z]+\z/
+                node.remove_attribute('class')
+              end
+            when 'p'
+              unless node['class'] == 'markdown-alert-title'
+                node.remove_attribute('class')
+              end
+            end
+          }
+
           # Allow table cell alignment by style attribute
           #
           # Only necessary if we used the TABLE_PREFER_STYLE_ATTRIBUTES
diff --git a/test/unit/lib/redmine/wiki_formatting/common_mark/formatter_test.rb b/test/unit/lib/redmine/wiki_formatting/common_mark/formatter_test.rb
index 79581a928..d9a84a2c2 100644
--- a/test/unit/lib/redmine/wiki_formatting/common_mark/formatter_test.rb
+++ b/test/unit/lib/redmine/wiki_formatting/common_mark/formatter_test.rb
@@ -163,39 +163,39 @@ class Redmine::WikiFormatting::CommonMark::FormatterTest < ActionView::TestCase
       # 0
       <<~STR.chomp,
         # Title
-  
+
         Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Maecenas sed libero.
       STR
       # 1
       <<~STR.chomp,
         ## Heading 2
-  
+
         ~~~ruby
           def foo
           end
         ~~~
-  
+
         Morbi facilisis accumsan orci non pharetra.
-  
+
         ~~~ ruby
         def foo
         end
         ~~~
-  
+
         ```
         Pre Content:
-  
+
         ## Inside pre
-  
+
         <tag> inside pre block
-  
+
         Morbi facilisis accumsan orci non pharetra.
         ```
       STR
       # 2
       <<~STR.chomp,
         ### Heading 3
-  
+
         Nulla nunc nisi, egestas in ornare vel, posuere ac libero.
       STR
     ]
@@ -299,6 +299,45 @@ class Redmine::WikiFormatting::CommonMark::FormatterTest < ActionView::TestCase
       assert_equal expected.gsub(%r{[\r\n\t]}, ''), to_html(text).gsub(%r{[\r\n\t]}, '').rstrip
     end
 
+    def test_should_render_alert_blocks
+      text = <<~MD
+        > [!note]
+        > This is a note.
+
+        > [!tip]
+        > This is a tip.
+
+        > [!warning]
+        > This is a warning.
+
+        > [!caution]
+        > This is a caution.
+
+        > [!important]
+        > This is a important.
+      MD
+
+      html = to_html(text)
+      %w[note tip warning caution important].each do |alert|
+        assert_include "<div class=\"markdown-alert markdown-alert-note\">\n<p class=\"markdown-alert-title\">Note</p>\n<p>This is a note.</p>\n</div>", html
+      end
+    end
+
+    def test_should_not_render_unknown_alert_type
+      text = <<~MD
+        > [!unknown]
+        > This should not become an alert.
+      MD
+
+      html = to_html(text)
+
+      assert_include "<blockquote>", html
+      assert_include "[!unknown]", html
+      assert_include "This should not become an alert.", html
+
+      assert_not_include 'markdown-alert', html
+    end
+
     private
 
     def assert_section_with_hash(expected, text, index)
diff --git a/test/unit/lib/redmine/wiki_formatting/common_mark/sanitization_filter_test.rb b/test/unit/lib/redmine/wiki_formatting/common_mark/sanitization_filter_test.rb
index 4c0282f2d..d17c2a09f 100644
--- a/test/unit/lib/redmine/wiki_formatting/common_mark/sanitization_filter_test.rb
+++ b/test/unit/lib/redmine/wiki_formatting/common_mark/sanitization_filter_test.rb
@@ -71,6 +71,32 @@ if Object.const_defined?(:Commonmarker)
       assert_equal %(<code>foo</code>), filter(input)
     end
 
+    def test_should_allow_valid_alert_div_and_p_classes
+      html = <<~HTML
+        <div class="markdown-alert markdown-alert-tip">
+          <p class="markdown-alert-title">Tip</p>
+          <p>Useful tip.</p>
+        </div>
+      HTML
+
+      sanitized = filter(html)
+
+      assert_include 'class="markdown-alert markdown-alert-tip"', sanitized
+      assert_include 'class="markdown-alert-title"', sanitized
+    end
+
+    def test_should_remove_invalid_div_class
+      html = '<div class="bad-class">Text</div>'
+      sanitized = filter(html)
+      refute_include 'bad-class', sanitized
+    end
+
+    def test_should_remove_invalid_p_class
+      html = '<p class="bad-class">Text</p>'
+      sanitized = filter(html)
+      assert_not_include 'bad-class', sanitized
+    end
+
     def test_should_allow_links_with_safe_url_schemes
       %w(http https ftp ssh foo).each do |scheme|
         input = %(<a href="#{scheme}://example.org/">foo</a>)