Fix error when tag.render <code> (#2461)

lib/extend/tag.js

@@ -62,7 +62,7 @@ Tag.prototype.render = function(str, options, callback) {
   var env = this.env;
 
   return new Promise(function(resolve, reject) {
-    str = str.replace(/<pre><code.*>[\s\S]*?<\/code><\/pre>/gm, escapeContent);
+    str = str.replace(/(?:<pre>)?<code.*>[\s\S]*?<\/code>(?:<\/pre>)?/gm, escapeContent);
     env.renderString(str, options, function(err, result) {
       if (err) return reject(err);
       resolve(result.replace(rPlaceholder, function() {

test/scripts/extend/tag.js

@@ -148,4 +148,20 @@ describe('Tag', () => {
       result.should.eql('bar');
     });
   });
+
+  it('render() - ignore <pre><code>', function() {
+    var str = '<pre><code>{{ helper.json() }}</code></pre>';
+
+    return tag.render(str).then(function(result) {
+      result.should.eql(str);
+    });
+  });
+
+  it('render() - ignore <code>', function() {
+    var str = '<code>{{ helper.json() }}</code>';
+
+    return tag.render(str).then(function(result) {
+      result.should.eql(str);
+    });
+  });
 });

test/scripts/hexo/post.js

@@ -640,15 +640,15 @@ describe('Post', () => {
       content,
       engine: 'markdown'
     }).then(data => {
-      data.content.trim().should.eql('<p><code>{{ test }}</code></p>');
+      data.content.trim().should.eql('<p><code>{% raw %}{{ test }}{% endraw %}</code></p>');
     });
   });
 
   it('render() - recover escaped swig blocks which is html escaped before post_render', () => {
     var content = '`{% raw %}{{ test }}{% endraw %}`';
 
     var filter = sinon.spy(result => {
-      result.trim().should.eql('<p><code>{{ test }}</code></p>');
+      result.trim().should.eql('<p><code>{% raw %}{{ test }}{% endraw %}</code></p>');
     });
 
     hexo.extend.filter.register('after_render:html', filter);