feat: added option onlyInternal excluding external links

package.json

@@ -34,6 +34,7 @@
     "style"
   ],
   "dependencies": {
+    "is-absolute-url": "^3.0.3",
     "is-url": "^1.2.4",
     "nanoid": "^3.0.2",
     "normalize-url": "5.0.0",

readme.md

@@ -66,16 +66,21 @@ output.html
 ## Options
 
 ### `tags`
-Type: `Array`  
-Default: `['script', 'link']`  
-Description: *You can also expand the list by adding the tags you need...*  
+Type: `Array`
+Default: `['script', 'link']`
+Description: *You can also expand the list by adding the tags you need...*
 
 ### `attributes`
-Type: `Array`  
-Default: `['src', 'href']` 
-Description: *You can also expand the list by adding the attributes you need...*  
+Type: `Array`
+Default: `['src', 'href']`
+Description: *You can also expand the list by adding the attributes you need...*
 
 ### `exclude`
-Type: `Array`  
-Default: `[]`  
-Description: *You can also exclude the list by adding the tags you need...*  
+Type: `Array`
+Default: `[]`
+Description: *You can also exclude the list by adding the tags you need...*
+
+### `onlyInternal`
+Type: `Array`
+Default: `[]`
+Description: *If you have external URL-s, some won't work if you add nanoid to them. If this list is empty, all external links are modified. Otherwise, only the URL-s starting with items in the array (case insensitive) will be modified. E.g. `['https://github.com/']` will add nanoid to all local links and only to `https://github.com/*`. It won't add nanoid to e.g. `http://github.com` or  `https://fonts.google.com`. For simplicity, a link is considered external if it starts with a protocol (see [is-absolute-url](https://www.npmjs.com/package/is-absolute-url)) or with double slash `//`.*

src/index.js

@@ -2,18 +2,30 @@ import {nanoid} from 'nanoid';
 import isUrl from 'is-url';
 import queryString from 'query-string';
 import normalizeUrl from 'normalize-url';
+import isAbsoluteUrl from 'is-absolute-url';
 
-const setNanoid = url => {
-  const id = nanoid();
+const setNanoid = (onlyInternal, url) => {
   const fullUrl = /^[/?]/.test(url) ? `foo.bar${url}` : url;
 
+  if (onlyInternal.length > 0) {
+    const isAbsolute = isAbsoluteUrl(url) || url.startsWith('//');
+    if (isAbsolute) {
+      const absoluteUrl = normalizeUrl(url, {normalizeProtocol: false}).toLowerCase();
+      if (onlyInternal.every(start => !absoluteUrl.startsWith(start.toLowerCase()))) {
+        return url;
+      }
+    }
+  }
+
   if (!isUrl(normalizeUrl(fullUrl))) {
     return url;
   }
 
+  const id = nanoid();
+
   let [uri, query] = url.split('?');
   query = queryString.parse(query);
-  query.v = query.v ? query.v : id;
+  query.v = query.v || id;
   query = queryString.stringify(query);
 
   return `${uri}?${query}`;
@@ -44,11 +56,13 @@ export default (options = {}) => {
       resolve(tree);
     }
 
+    const onlyInternal = options.onlyInternal && Array.isArray(options.onlyInternal) ? options.onlyInternal : [];
+
     tree.walk(node => {
       if (node.tag && node.attrs) {
         node.attrs = Object.keys(node.attrs).reduce((attributeList, attr) => {
           if (tags.includes(node.tag) && attributes.includes(attr)) {
-            return Object.assign(attributeList, {[attr]: setNanoid(node.attrs[attr])});
+            return Object.assign(attributeList, {[attr]: setNanoid(onlyInternal, node.attrs[attr])});
           }
 
           return attributeList;

test/test-plugin.js

@@ -131,6 +131,69 @@ test('should add nano id for root path', async t => {
   t.is(id.length, 21);
 });
 
+test('should add nano id for external link', async t => {
+  const input = '<link rel="stylesheet" href="https://foo.com/style.css">';
+  const html = (await processing(input)).html;
+
+  const {url, id} = getParts(html, 'href');
+  const rel = parser(html)[0].attrs.rel;
+  t.truthy(id);
+  t.truthy(rel);
+  t.is(rel, 'stylesheet');
+  t.is(url, 'https://foo.com/style.css');
+  t.is(id.length, 21);
+});
+
+test('should add nano id for allowed external link', async t => {
+  const input = '<link rel="stylesheet" href="https://FOO.com/style.css">';
+  const html = (await processing(input, {onlyInternal: ['https://foo.com/']})).html;
+
+  const {url, id} = getParts(html, 'href');
+  const rel = parser(html)[0].attrs.rel;
+  t.truthy(id);
+  t.truthy(rel);
+  t.is(rel, 'stylesheet');
+  t.is(url, 'https://FOO.com/style.css');
+  t.is(id.length, 21);
+});
+
+test('shouldn\'t add nano id for disallowed external link', async t => {
+  const input = '<link rel="stylesheet" href="https://foo.com/style.css">';
+  const html = (await processing(input, {onlyInternal: ['http://foo.com/']})).html;
+
+  const {url, id} = getParts(html, 'href');
+  const rel = parser(html)[0].attrs.rel;
+  t.falsy(id);
+  t.truthy(rel);
+  t.is(rel, 'stylesheet');
+  t.is(url, 'https://foo.com/style.css');
+});
+
+test('should add nano id for disallowed protocol-less external link', async t => {
+  const input = '<link rel="stylesheet" href="//FOO.com/style.css">';
+  const html = (await processing(input, {onlyInternal: ['//foo.com/']})).html;
+
+  const {url, id} = getParts(html, 'href');
+  const rel = parser(html)[0].attrs.rel;
+  t.truthy(id);
+  t.truthy(rel);
+  t.is(rel, 'stylesheet');
+  t.is(url, '//FOO.com/style.css');
+  t.is(id.length, 21);
+});
+
+test('shouldn\'t add nano id for disallowed protocol-less external link', async t => {
+  const input = '<link rel="stylesheet" href="//foo.com/style.css">';
+  const html = (await processing(input, {onlyInternal: ['//foo.org/']})).html;
+
+  const {url, id} = getParts(html, 'href');
+  const rel = parser(html)[0].attrs.rel;
+  t.falsy(id);
+  t.truthy(rel);
+  t.is(rel, 'stylesheet');
+  t.is(url, '//foo.com/style.css');
+});
+
 function getParts(html, attributeName) {
   const parts = parser(html)[0].attrs[attributeName].split('?');
   const url = parts[0];