Sniff H2 sections when ingesting documents

Documents may already have NAME sections which already have name and
tagline, so we should try that before looking at the H1 header.

The sections may use the hyphenated form, which we can split up as
name and tagline, or they may just have the name of the page.  We can
handle both.

lib/ronn/document.rb

@@ -214,7 +214,25 @@ def sniff
       html = Kramdown::Document.new(data[0, 512], auto_ids: false,
         smart_quotes: ['apos', 'apos', 'quot', 'quot'],
         typographic_symbols: { hellip: '...', ndash: '--', mdash: '--' }).to_html
-      sniff_h1_heading(html) or [nil, nil, nil]
+      sniff_h2_headings(html) or sniff_h1_heading(html) or [nil, nil, nil]
+    end
+
+    # If the document has a '## NAME' heading, see if we can sniff out
+    # some of the document metadata.
+    def sniff_h2_headings(html)
+      html.split('<h2>').each do |section|
+        case section
+        when /^NAME<\/h2>\s*<p>([\w_.\/\[\]~+=@:<>-]+)\s+-+\s+([\w_.\/\[\]~+=@: -]*)<\/p>/m
+          # name -- description
+          description = $2
+          name = $1.gsub(/<[^>]+>/, '')
+          return [name, nil, description]
+        when /^NAME<\/h2>\s*<p>([\w_.\/\[\]~+=@:<>-]+)<\/p>/m
+          # name
+          return [$1.gsub(/<[^>]+>/, ''), nil, nil]
+        end
+      end
+      nil
     end
 
     # If the document has a top-level '# <data>' type heading, see

test/test_ronn_document.rb

@@ -74,6 +74,18 @@ def canonicalize(text)
       assert_equal '5', doc.section
       assert_equal 'wootderitis', doc.tagline
     end
+
+    test "new with NAME heading with #{i} dashes and description" do
+      doc = Ronn::Document.new { "# whatever\n\n## NAME\n\n`foo` #{dashes} bar" }
+      assert_equal 'foo', doc.name
+      assert_equal 'bar', doc.tagline
+    end
+  end
+
+  test 'new with NAME heading without description' do
+    doc = Ronn::Document.new { "# whatever\n\n## NAME\n\n`foo`" }
+    assert_equal 'foo', doc.name
+    assert_equal nil, doc.tagline
   end
 
   context 'simple conventionally named document' do