add tests

spec/jekyll_seo_tag_spec.rb

@@ -110,7 +110,7 @@ describe Jekyll::SeoTag do
       end
     end
 
-    context 'with page.image' do
+    context 'with page.image as a string' do
       let(:page) { make_page('image' => '/img/foo.png') }
 
       it 'outputs the image' do
@@ -119,6 +119,47 @@ describe Jekyll::SeoTag do
       end
     end
 
+    context 'with page.image as an object' do
+      context 'when given a path' do
+        let(:page) { make_page('image' => { 'path' => '/img/foo.png' } ) }
+
+        it 'outputs the image' do
+          expected = %r{<meta property="og:image" content="http://example.invalid/img/foo.png" />}
+          expect(output).to match(expected)
+        end
+      end
+
+      context "when given a facebook image" do
+        let(:page) { make_page('image' => { 'facebook' => '/img/facebook.png' } ) }
+
+        it 'outputs the image' do
+          expected = %r{<meta property="og:image" content="http://example.invalid/img/facebook.png" />}
+          expect(output).to match(expected)
+        end
+      end
+
+      context "when given a twitter image" do
+        let(:page) { make_page('image' => { 'twitter' => '/img/twitter.png' } ) }
+
+        it 'outputs the image' do
+          expected = %r{<meta name="twitter:image" content="http://example.invalid/img/twitter.png" />}
+          expect(output).to match(expected)
+        end
+      end
+
+      context "when given the image height and width" do
+        let(:image) { { 'facebook' => '/img/foo.png', 'height' => 1, 'width' => 2 } }
+        let(:page) { make_page('image' => image) }
+
+        it 'outputs the image' do
+          expected = %r{<meta property="og:image:height" content="1" />}
+          expect(output).to match(expected)
+          expected = %r{<meta property="og:image:width" content="2" />}
+          expect(output).to match(expected)
+        end
+      end
+    end
+
     context 'with site.logo' do
       let(:site) { make_site('logo' => '/logo.png', 'url' => 'http://example.invalid') }