Review comment (#2459)

frontend/src/utils/seafile-markdown2html.js

@@ -0,0 +1,54 @@
+var unified = require('unified');
+var markdown = require('remark-parse');
+var slug = require('remark-slug');
+var breaks = require('remark-breaks');
+var remark2rehype = require('remark-rehype');
+var format = require('rehype-format');
+var raw = require('rehype-raw');
+var xtend = require('xtend');
+var toHTML = require('hast-util-to-html');
+var sanitize = require('hast-util-sanitize');
+var gh = require('hast-util-sanitize/lib/github');
+var deepmerge = require('deepmerge').default;
+
+function stringify(config) {
+  var settings = xtend(config, this.data('settings'));
+  var schema = deepmerge(gh, {
+    "attributes":{
+      "input": [
+        "type",
+      ],
+      "li": [
+        "className"
+      ],
+      "code":[
+        "className",
+      ],
+    },
+    "tagNames": [
+      "input",
+      "code"
+    ]
+  });
+  this.Compiler = compiler;
+
+  function compiler(tree) {
+    var hast = sanitize(tree, schema);
+    return toHTML(hast, settings);
+  }
+}
+
+var processor = unified()
+  .use(markdown, {commonmark: true})
+  .use(breaks)
+  .use(slug)
+  .use(remark2rehype, {allowDangerousHTML: true})
+  .use(raw)
+  .use(format)
+  .use(stringify);
+
+var processorGetAST = unified()
+  .use(markdown, {commonmark: true})
+  .use(slug)
+
+export { processor, processorGetAST };