feat: meta_generator helper (#3782)

* feat: add meta_generator helper
* test: add meta_generator helper

Author: SukkaW

lib/plugins/helper/index.js

@@ -43,6 +43,8 @@ module.exports = ctx => {
   helper.register('list_tags', require('./list_tags'));
   helper.register('list_posts', require('./list_posts'));
 
+  helper.register('meta_generator', require('./meta_generator'));
+
   helper.register('open_graph', require('./open_graph'));
 
   helper.register('number_format', require('./number_format'));

lib/plugins/helper/meta_generator.js

@@ -0,0 +1,7 @@
+'use strict';
+
+function metaGeneratorHelper() {
+  return `<meta name="generator" content="Hexo ${this.version}">`;
+}
+
+module.exports = metaGeneratorHelper;

test/scripts/helpers/index.js

@@ -19,6 +19,7 @@ describe('Helpers', () => {
   require('./list_tags');
   require('./mail_to');
   require('./markdown');
+  require('./meta_generator');
   require('./number_format');
   require('./open_graph');
   require('./paginator');

test/scripts/helpers/meta_generator.js

@@ -0,0 +1,12 @@
+'use strict';
+
+describe('meta_generator', () => {
+  const Hexo = require('../../../lib/hexo');
+  const hexo = new Hexo();
+
+  const metaGeneratorHelper = require('../../../lib/plugins/helper/meta_generator').bind(hexo);
+
+  it('default', () => {
+    metaGeneratorHelper().should.eql(`<meta name="generator" content="Hexo ${hexo.version}">`);
+  });
+});