Merge a4a2873 into fb02cc9

README.md

@@ -25,6 +25,7 @@ Utilities for [Hexo].
 - [hash](#hashstr)
 - [highlight](#highlightstr-options)
 - [htmlTag](#htmltagtag-attrs-text-escape)
+- [isExternalLink](#isexternallinkurl)
 - [Pattern](#patternrule)
 - [Permalink](#permalinkrule-options)
 - [relative_url](#relative_urlfrom-to)
@@ -256,6 +257,42 @@ htmlTag('script', {src: '/foo.js', async: true}, '')
 // <script src="/foo.js" async></script>
 ```
 
+### isExternalLink(url)
+
+Returns if a given url is external link relative to `config.url` and `config.exclude`.
+
+``` yml
+_config.yml
+url: https://example.com # example
+```
+
+``` js
+isExternalLink('https://example.com');
+// false
+isExternalLink('/archives/foo.html');
+// false
+isExternalLink('https://foo.com/');
+// true
+```
+
+``` yml
+_config.yml
+url: https://example.com # example
+exclude:
+  - foo.com
+  - bar.com
+```
+
+``` js
+isExternalLink('https://foo.com');
+// false
+isExternalLink('https://bar.com');
+// false
+isExternalLink('https://baz.com/');
+// true
+```
+
+
 ### Pattern(rule)
 
 Parses the string and tests if the string matches the rule. `rule` can be a string, a regular expression or a function.
@@ -451,6 +488,7 @@ Following utilities require `bind(hexo)` / `bind(this)` / `call(hexo, input)` /
 - [`full_url_for()`](#full_url_forpath)
 - [`url_for()`](#url_forpath)
 - [`relative_url()`](#relative_urlfrom-to)
+- [`isExternalLink()`](#isexternallinkurl)
 
 Below examples demonstrate different approaches to creating a [helper](https://hexo.io/api/helper) (each example is separated by `/******/`),
 

lib/index.js

@@ -17,6 +17,7 @@ exports.hash = hash.hash;
 exports.HashStream = hash.HashStream;
 exports.highlight = require('./highlight');
 exports.htmlTag = require('./html_tag');
+exports.isExternalLink = require('./isExternalLink');
 exports.Pattern = require('./pattern');
 exports.Permalink = require('./permalink');
 exports.relative_url = require('./relative_url');

lib/is_external_link.js

@@ -0,0 +1,43 @@
+'use strict';
+
+const { URL } = require('url');
+
+const urlObj = (str) => {
+  try {
+    return new URL(str);
+  } catch (err) {
+    return str;
+  }
+};
+
+/**
+ * Check whether the link is external
+ * @param {String} url The url to check
+ * @returns {Boolean} True if the link doesn't have protocol or link has same host with config.url
+ */
+
+function isExternalLink(url) {
+  const { config } = this;
+  const exclude = Array.isArray(config.external_link.exclude) ? config.external_link.exclude
+    : [config.external_link.exclude];
+  const data = urlObj(url);
+  const host = data.hostname;
+  const sitehost = typeof urlObj(config.url) === 'object' ? urlObj(config.url).hostname : config.url;
+
+  if (!sitehost || typeof data === 'string') return false;
+
+  // handle mailto: javascript: vbscript: and so on
+  if (data.origin === 'null') return false;
+
+  if (exclude && exclude.length) {
+    for (const i of exclude) {
+      if (host === i) return false;
+    }
+  }
+
+  if (host !== sitehost) return true;
+
+  return false;
+}
+
+module.exports = isExternalLink;

test/is_external_link.spec.js

@@ -0,0 +1,48 @@
+'use strict';
+
+describe('isExternalLink', () => {
+  const ctx = {
+    config: {
+      url: 'https://example.com',
+      external_link: {}
+    }
+  };
+
+  const isExternalLink = require('../lib/is_external_link').bind(ctx);
+
+  it('external link', () => {
+    isExternalLink('https://hexo.io/').should.eql(true);
+  });
+
+  it('internal link', () => {
+    isExternalLink('https://example.com').should.eql(false);
+    isExternalLink('//example.com').should.eql(false);
+    isExternalLink('//example.com/archives/foo.html').should.eql(false);
+    isExternalLink('/archives/foo.html').should.eql(false);
+  });
+
+  it('hash, mailto, javascript', () => {
+    isExternalLink('#top').should.eql(false);
+    isExternalLink('mailto:hi@hexo.io').should.eql(false);
+    isExternalLink('javascript:alert(\'Hexo is Awesome\')').should.eql(false);
+  });
+
+  it('exclude - empty string', () => {
+    ctx.config.external_link.exclude = '';
+    isExternalLink('https://hexo.io/').should.eql(true);
+  });
+
+  it('exclude - string', () => {
+    ctx.config.external_link.exclude = 'foo.com';
+    isExternalLink('https://foo.com/').should.eql(false);
+    isExternalLink('https://bar.com/').should.eql(true);
+    isExternalLink('https://baz.com/').should.eql(true);
+  });
+
+  it('exclude - array', () => {
+    ctx.config.external_link.exclude = ['foo.com', 'bar.com'];
+    isExternalLink('https://foo.com/').should.eql(false);
+    isExternalLink('https://bar.com/').should.eql(false);
+    isExternalLink('https://baz.com/').should.eql(true);
+  });
+});