don't require the host to be in the Image tag

now that we know our base host via config, we can stop hardcoding it in
each Image tag

Signed-off-by: Brian S. Stephan <bss@incorporeal.org>

tests/functional_markdown_tests.py

@@ -63,3 +63,16 @@ def test_figures_are_rendered():
                     '<span></span></figure>') in data
             assert '<figure><img alt="just a logo" src="bss-square-no-bg.png" /></figure>' in data
     os.chdir(HERE)
+
+
+def test_og_image():
+    """Test that the og:image meta tag is present as expected."""
+    with tempfile.TemporaryDirectory() as tmpdir:
+        src_dir = os.path.join(HERE, 'instance')
+        ssg = StaticSiteGenerator(src_dir, tmpdir)
+        os.chdir(os.path.join(src_dir, 'pages'))
+
+        ssg.build_file_in_destination(os.path.join(HERE, 'instance', 'pages'), '', 'more-metadata.md', tmpdir, True)
+        with open(os.path.join(tmpdir, 'more-metadata.html'), 'r') as graphviz_output:
+            data = graphviz_output.read()
+            assert ('<meta property="og:image" content="http://example.org/test.img') in data

tests/instance/pages/more-metadata.md

@@ -1,6 +1,6 @@
 Title:          title for the page
 Description:    description of this page
                 made even longer
-Image:          http://buh.com/test.img
+Image:          /test.img
 
 hello