Add gfm plugins

src/tables.js

@@ -0,0 +1,55 @@
+var rules = {}
+
+rules.tableCell = {
+  filter: ['th', 'td'],
+  replacement: function (content, node) {
+    return cell(content, node)
+  }
+}
+
+rules.tableRow = {
+  filter: 'tr',
+  replacement: function (content, node) {
+    var borderCells = ''
+    var alignMap = { left: ':--', right: '--:', center: ':-:' }
+
+    if (node.parentNode.nodeName === 'THEAD') {
+      for (var i = 0; i < node.childNodes.length; i++) {
+        var align = node.childNodes[i].attributes.align
+        var border = '---'
+
+        if (align) border = alignMap[align.value] || border
+
+        borderCells += cell(border, node.childNodes[i])
+      }
+    }
+    return '\n' + content + (borderCells ? '\n' + borderCells : '')
+  }
+}
+
+rules.table = {
+  filter: 'table',
+  replacement: function (content) {
+    // Ensure there are no blank lines
+    content = content.replace('\n\n', '\n')
+    return '\n\n' + content + '\n\n'
+  }
+}
+
+rules.tableSection = {
+  filter: ['thead', 'tbody', 'tfoot'],
+  replacement: function (content) {
+    return content
+  }
+}
+
+function cell (content, node) {
+  var index = Array.prototype.indexOf.call(node.parentNode.childNodes, node)
+  var prefix = ' '
+  if (index === 0) prefix = '| '
+  return prefix + content + ' |'
+}
+
+export default function tables (turndownService) {
+  for (var key in rules) turndownService.addRule(key, rules[key])
+}