fix(escapeAllSwigTags): check tag completeness (#5395)

Author: uiolee

Diff for: lib/hexo/post.ts

@@ -69,6 +69,9 @@ class PostRenderEscape {
    * @returns string
    */
   escapeAllSwigTags(str: string) {
+    if (!/(\{\{.+?\}\})|(\{#.+?#\})|(\{%.+?%\})/.test(str)) {
+      return str;
+    }
     let state = STATE_PLAINTEXT;
     let buffer = '';
     let output = '';
@@ -86,6 +89,7 @@ class PostRenderEscape {
 
       if (state === STATE_PLAINTEXT) { // From plain text to swig
         if (char === '{') {
+          // check if it is a complete tag {{ }}
           if (next_char === '{') {
             state = STATE_SWIG_VAR;
             idx++;

Diff for: test/scripts/hexo/post.js

@@ -12,7 +12,7 @@ const escapeSwigTag = str => str.replace(/{/g, '{').replace(/}/g, '}')
 describe('Post', () => {
   const Hexo = require('../../../dist/hexo');
   const hexo = new Hexo(join(__dirname, 'post_test'));
-  require('../../../lib/plugins/highlight/')(hexo);
+  require('../../../dist/plugins/highlight/')(hexo);
   const { post } = hexo;
   const now = Date.now();
   let clock;
@@ -1369,4 +1369,31 @@ describe('Post', () => {
 
     hexo.config.syntax_highlighter = 'highlight.js';
   });
+
+  // https://github.com/hexojs/hexo/issues/5301
+  it('render() - dont escape uncomplete tags', async () => {
+    const content = 'dont drop `{% }` 11111 `{# }` 22222 `{{ }` 33333';
+
+    const data = await post.render(null, {
+      content,
+      engine: 'markdown'
+    });
+
+    data.content.should.contains('11111');
+    data.content.should.contains('22222');
+    data.content.should.contains('33333');
+    data.content.should.not.contains('`'); // `
+  });
+
+  it('render() - uncomplete tags throw error', async () => {
+    const content = 'nunjucks should thorw {#  } error';
+
+    try {
+      await post.render(null, {
+        content,
+        engine: 'markdown'
+      });
+      should.fail();
+    } catch (err) {}
+  });
 });