Use attribute name consistently for metadata under twitter namespace (#437)

Merge pull request 437

Author: tordans

lib/template.html

@@ -17,8 +17,7 @@
 
 {% if seo_tag.description %}
   <meta name="description" content="{{ seo_tag.description }}" />
-  <meta property="og:description" content="{{ seo_tag.description }}" />
-  <meta property="twitter:description" content="{{ seo_tag.description }}" />
+  <meta name="twitter:description" property="og:description" content="{{ seo_tag.description }}" />
 {% endif %}
 
 {% if site.url %}
@@ -59,7 +58,7 @@
 
 {% if seo_tag.image %}
   <meta name="twitter:card" content="{{ page.twitter.card | default: site.twitter.card | default: "summary_large_image" }}" />
-  <meta property="twitter:image" content="{{ seo_tag.image.path }}" />
+  <meta name="twitter:image" content="{{ seo_tag.image.path }}" />
 {% else %}
   <meta name="twitter:card" content="summary" />
 {% endif %}
@@ -69,7 +68,7 @@
 {% endif %}
 
 {% if seo_tag.page_title %}
-  <meta property="twitter:title" content="{{ seo_tag.page_title }}" />
+  <meta name="twitter:title" content="{{ seo_tag.page_title }}" />
 {% endif %}
 
 {% if site.twitter %}

spec/jekyll_seo_tag_integration_spec.rb

@@ -123,8 +123,7 @@
 
     it "uses the page description" do
       expect(output).to match(%r!<meta name="description" content="foo" />!)
-      expect(output).to match(%r!<meta property="og:description" content="foo" />!)
-      expect(output).to match(%r!<meta property="twitter:description" content="foo" />!)
+      expect(output).to match(%r!<meta name="twitter:description" property="og:description" content="foo" />!)
     end
   end
 
@@ -133,8 +132,7 @@
 
     it "uses the page excerpt when no page description exists" do
       expect(output).to match(%r!<meta name="description" content="foo" />!)
-      expect(output).to match(%r!<meta property="og:description" content="foo" />!)
-      expect(output).to match(%r!<meta property="twitter:description" content="foo" />!)
+      expect(output).to match(%r!<meta name="twitter:description" property="og:description" content="foo" />!)
     end
   end
 
@@ -143,8 +141,7 @@
 
     it "uses the site description when no page description nor excerpt exist" do
       expect(output).to match(%r!<meta name="description" content="foo" />!)
-      expect(output).to match(%r!<meta property="og:description" content="foo" />!)
-      expect(output).to match(%r!<meta property="twitter:description" content="foo" />!)
+      expect(output).to match(%r!<meta name="twitter:description" property="og:description" content="foo" />!)
     end
   end