From 4cb239064967d1ead2b24a3558cd7715740e6d07 Mon Sep 17 00:00:00 2001
From: MDLeom <43627182+curbengh@users.noreply.github.com>
Date: Fri, 24 Jul 2020 10:33:49 +0100
Subject: [PATCH] feat: add 'noreferrer' option

---
 README.md     |  2 ++
 index.js      |  3 ++-
 lib/filter.js |  9 ++++++---
 package.json  |  1 +
 test/index.js | 39 ++++++++++++++++++++++++++++++++++++---
 5 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index f850823..0dd797f 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,7 @@ nofollow:
   exclude:
     - 'exclude1.com'
     - 'exclude2.com'
+  noreferrer: true
 ```
 
 - **enable** - Enable the plugin. Default value is `true`.
@@ -32,3 +33,4 @@ nofollow:
   - 'site' - Add nofollow attribute to external links of whole sites
 - **exclude** - Exclude hostname. Specify subdomain when applicable, including `www`.
   - 'exclude1.com' does not apply to `www.exclude1.com` nor `en.exclude1.com`.
+- **noreferrer** - Add noreferrer to `rel` attribute.
diff --git a/index.js b/index.js
index 9f05fd5..3dad53c 100755
--- a/index.js
+++ b/index.js
@@ -5,7 +5,8 @@
 hexo.config.nofollow = Object.assign({
   enable: true,
   field: 'site',
-  exclude: []
+  exclude: [],
+  noreferrer: true
 }, hexo.config.nofollow);
 
 const config = hexo.config.nofollow;
diff --git a/lib/filter.js b/lib/filter.js
index 5e70272..de83673 100755
--- a/lib/filter.js
+++ b/lib/filter.js
@@ -24,8 +24,9 @@ function isExternal(url, config) {
 module.exports = function(data) {
   const hexo = this;
   const config = hexo.config;
+  const { exclude: excludeCfg, field, noreferrer } = config.nofollow;
 
-  const exclude = config.nofollow.exclude;
+  const exclude = excludeCfg;
   if (exclude && !Array.isArray(exclude)) {
     config.nofollow.exclude = [exclude];
   }
@@ -34,7 +35,9 @@ module.exports = function(data) {
     return data.replace(/<a.*?(href=['"](.*?)['"]).*?>/gi, (str, hrefStr, href) => {
       if (!isExternal(href, config)) return str;
 
-      let noFollow = ['noopener', 'external', 'nofollow', 'noreferrer'];
+      let noFollow = noreferrer || noreferrer == null
+        ? ['noopener', 'external', 'nofollow', 'noreferrer']
+        : ['noopener', 'external', 'nofollow'];
 
       if (/rel=/gi.test(str)) {
         str = str.replace(/\srel="(.*?)"/gi, (relStr, rel) => {
@@ -51,7 +54,7 @@ module.exports = function(data) {
     });
   };
 
-  if (config.nofollow.field === 'post') {
+  if (field === 'post') {
     data.content = filterExternal(data.content);
   } else {
     data = filterExternal(data);
diff --git a/package.json b/package.json
index 97a0535..a86c0b4 100644
--- a/package.json
+++ b/package.json
@@ -36,6 +36,7 @@
     "eslint": "^6.2.2",
     "eslint-config-hexo": "^3.0.0",
     "hexo": "hexojs/hexo",
+    "hexo-util": "^2.2.0",
     "mocha": "^6.2.0"
   }
 }
diff --git a/test/index.js b/test/index.js
index 161b609..c9b5a5e 100755
--- a/test/index.js
+++ b/test/index.js
@@ -1,15 +1,26 @@
 'use strict';
 
 require('chai').should();
+const Hexo = require('hexo');
+const { deepMerge } = require('hexo-util');
 
 describe('hexo-filter-nofollow', () => {
-  const Hexo = require('hexo');
   const hexo = new Hexo();
-
   const nofollowFilter = require('../lib/filter').bind(hexo);
 
   hexo.config.url = 'https://example.com';
-  hexo.config.nofollow = {};
+  const defaultCfg = deepMerge(hexo.config, {
+    nofollow: {
+      enable: true,
+      field: 'site',
+      exclude: [],
+      noreferrer: true
+    }
+  });
+
+  beforeEach(() => {
+    hexo.config = deepMerge({}, defaultCfg);
+  });
 
   describe('Default', () => {
     const content = [
@@ -118,4 +129,26 @@ describe('hexo-filter-nofollow', () => {
       ].join('\n'));
     });
   });
+
+  describe('noreferrer', () => {
+    it('Default', () => {
+      const result = nofollowFilter('<a href="https://hexo.io/">Hexo</a>');
+
+      result.should.eql('<a href="https://hexo.io/" rel="noopener external nofollow noreferrer">Hexo</a>');
+    });
+
+    it('Disable', () => {
+      hexo.config.nofollow.noreferrer = false;
+      const result = nofollowFilter('<a href="https://hexo.io/">Hexo</a>');
+
+      result.should.eql('<a href="https://hexo.io/" rel="noopener external nofollow">Hexo</a>');
+    });
+
+    it('Retain original noreferrer', () => {
+      hexo.config.nofollow.noreferrer = false;
+      const result = nofollowFilter('<a href="https://hexo.io/" rel="noreferrer">Hexo</a>');
+
+      result.should.eql('<a href="https://hexo.io/" rel="noopener external nofollow noreferrer">Hexo</a>');
+    });
+  });
 });