Add support for incoming rich text (#23913)

4 files changed, 85 insertions, 27 deletions

diff --git a/app/javascript/styles/application.scss b/app/javascript/styles/application.scss
index 81a040108..1b2969c23 100644
--- a/app/javascript/styles/application.scss
+++ b/app/javascript/styles/application.scss
@@ -23,3 +23,4 @@
 @import 'mastodon/dashboard';
 @import 'mastodon/rtl';
 @import 'mastodon/accessibility';
+@import 'mastodon/rich_text';
diff --git a/app/javascript/styles/mastodon/rich_text.scss b/app/javascript/styles/mastodon/rich_text.scss
new file mode 100644
index 000000000..35901984b
--- /dev/null
+++ b/app/javascript/styles/mastodon/rich_text.scss
@@ -0,0 +1,64 @@
+.status__content__text,
+.e-content,
+.reply-indicator__content {
+  pre,
+  blockquote {
+    margin-bottom: 20px;
+    white-space: pre-wrap;
+    unicode-bidi: plaintext;
+
+    &:last-child {
+      margin-bottom: 0;
+    }
+  }
+
+  blockquote {
+    padding-left: 10px;
+    border-left: 3px solid $darker-text-color;
+    color: $darker-text-color;
+    white-space: normal;
+
+    p:last-child {
+      margin-bottom: 0;
+    }
+  }
+
+  & > ul,
+  & > ol {
+    margin-bottom: 20px;
+  }
+
+  b,
+  strong {
+    font-weight: 700;
+  }
+
+  em,
+  i {
+    font-style: italic;
+  }
+
+  ul,
+  ol {
+    margin-left: 2em;
+
+    p {
+      margin: 0;
+    }
+  }
+
+  ul {
+    list-style-type: disc;
+  }
+
+  ol {
+    list-style-type: decimal;
+  }
+}
+
+.reply-indicator__content {
+  blockquote {
+    border-left-color: $inverted-text-color;
+    color: $inverted-text-color;
+  }
+}
diff --git a/lib/sanitize_ext/sanitize_config.rb b/lib/sanitize_ext/sanitize_config.rb
index dc39e9c90..9cc500c36 100644
--- a/lib/sanitize_ext/sanitize_config.rb
+++ b/lib/sanitize_ext/sanitize_config.rb
@@ -51,29 +51,22 @@ class Sanitize
     end
 
     UNSUPPORTED_ELEMENTS_TRANSFORMER = lambda do |env|
-      return unless %w(h1 h2 h3 h4 h5 h6 blockquote pre ul ol li).include?(env[:node_name])
+      return unless %w(h1 h2 h3 h4 h5 h6).include?(env[:node_name])
 
       current_node = env[:node]
 
-      case env[:node_name]
-      when 'li'
-        current_node.traverse do |node|
-          next unless %w(p ul ol li).include?(node.name)
-
-          node.add_next_sibling('<br>') if node.next_sibling
-          node.replace(node.children) unless node.text?
-        end
-      else
-        current_node.name = 'p'
-      end
+      current_node.name = 'strong'
+      current_node.wrap('<p></p>')
     end
 
     MASTODON_STRICT ||= freeze_config(
-      elements: %w(p br span a),
+      elements: %w(p br span a del pre blockquote code b strong u i em ul ol li),
 
       attributes: {
         'a' => %w(href rel class),
         'span' => %w(class),
+        'ol' => %w(start reversed),
+        'li' => %w(value),
       },
 
       add_attributes: {
diff --git a/spec/lib/sanitize_config_spec.rb b/spec/lib/sanitize_config_spec.rb
index c9543ceb0..a01122bed 100644
--- a/spec/lib/sanitize_config_spec.rb
+++ b/spec/lib/sanitize_config_spec.rb
@@ -6,24 +6,16 @@ describe Sanitize::Config do
   describe '::MASTODON_STRICT' do
     subject { Sanitize::Config::MASTODON_STRICT }
 
-    it 'converts h1 to p' do
-      expect(Sanitize.fragment('<h1>Foo</h1>', subject)).to eq '<p>Foo</p>'
+    it 'converts h1 to p strong' do
+      expect(Sanitize.fragment('<h1>Foo</h1>', subject)).to eq '<p><strong>Foo</strong></p>'
     end
 
-    it 'converts ul to p' do
-      expect(Sanitize.fragment('<p>Check out:</p><ul><li>Foo</li><li>Bar</li></ul>', subject)).to eq '<p>Check out:</p><p>Foo<br>Bar</p>'
+    it 'keeps ul' do
+      expect(Sanitize.fragment('<p>Check out:</p><ul><li>Foo</li><li>Bar</li></ul>', subject)).to eq '<p>Check out:</p><ul><li>Foo</li><li>Bar</li></ul>'
     end
 
-    it 'converts p inside ul' do
-      expect(Sanitize.fragment('<ul><li><p>Foo</p><p>Bar</p></li><li>Baz</li></ul>', subject)).to eq '<p>Foo<br>Bar<br>Baz</p>'
-    end
-
-    it 'converts ul inside ul' do
-      expect(Sanitize.fragment('<ul><li>Foo</li><li><ul><li>Bar</li><li>Baz</li></ul></li></ul>', subject)).to eq '<p>Foo<br>Bar<br>Baz</p>'
-    end
-
-    it 'keep links in lists' do
-      expect(Sanitize.fragment('<p>Check out:</p><ul><li><a href="https://joinmastodon.org" rel="nofollow noopener noreferrer" target="_blank">joinmastodon.org</a></li><li>Bar</li></ul>', subject)).to eq '<p>Check out:</p><p><a href="https://joinmastodon.org" rel="nofollow noopener noreferrer" target="_blank">joinmastodon.org</a><br>Bar</p>'
+    it 'keeps start and reversed attributes of ol' do
+      expect(Sanitize.fragment('<p>Check out:</p><ol start="3" reversed=""><li>Foo</li><li>Bar</li></ol>', subject)).to eq '<p>Check out:</p><ol start="3" reversed=""><li>Foo</li><li>Bar</li></ol>'
     end
 
     it 'removes a without href' do
@@ -45,5 +37,13 @@ describe Sanitize::Config do
     it 'keeps a with href' do
       expect(Sanitize.fragment('<a href="http://example.com">Test</a>', subject)).to eq '<a href="http://example.com" rel="nofollow noopener noreferrer" target="_blank">Test</a>'
     end
+
+    it 'removes a with unparsable href' do
+      expect(Sanitize.fragment('<a href=" https://google.fr">Test</a>', subject)).to eq 'Test'
+    end
+
+    it 'keeps a with supported scheme and no host' do
+      expect(Sanitize.fragment('<a href="dweb:/a/foo">Test</a>', subject)).to eq '<a href="dweb:/a/foo" rel="nofollow noopener noreferrer" target="_blank">Test</a>'
+    end
   end
 end