templates: Update open graph metadata for some portico pages.

Closes #12580

templates/zerver/features.html

@@ -1,5 +1,8 @@
 {% extends "zerver/portico.html" %}
 
+{% set OPEN_GRAPH_TITLE = 'Zulip Features' %}
+{% set OPEN_GRAPH_DESCRIPTION = 'First class threading on top of everything you could want from real-time chat.' %}
+
 {% block customhead %}
 {{ render_bundle('landing-page') }}
 {% endblock %}

templates/zerver/for-open-source.html

@@ -1,5 +1,8 @@
 {% extends "zerver/portico.html" %}
 
+{% set OPEN_GRAPH_TITLE = 'Modern chat for open source' %}
+{% set OPEN_GRAPH_DESCRIPTION = 'No message limits, rich moderation features, markdown support, and a conversation model that scales to thousands of users.' %}
+
 {% block title %}
 <title>Zulip: the best group chat for open source projects</title>
 {% endblock %}

templates/zerver/why-zulip.html

@@ -1,5 +1,8 @@
 {% extends "zerver/portico.html" %}
 
+{% set OPEN_GRAPH_TITLE = 'Team chat with first-class threading' %}
+{% set OPEN_GRAPH_DESCRIPTION = 'Most team chats are overwhelming to keep up with. Zulip takes a different approach.' %}
+
 {% block title %}
 <title>The best group chat</title>
 {% endblock %}

zerver/tests/test_docs.py

@@ -155,6 +155,21 @@ class DocPageTest(ZulipTestCase):
         result = self.client_get('/static/favicon.ico')
         self.assertEqual(result.status_code, 200)
 
+    def test_portico_pages_open_graph_metadata(self) -> None:
+        # Why Zulip
+        url = '/why-zulip/'
+        title = '<meta property="og:title" content="Team chat with first-class threading">'
+        description = '<meta property="og:description" content="Most team chats are overwhelming'
+        self._test(url, title, doc_html_str=True)
+        self._test(url, description, doc_html_str=True)
+
+        # Features
+        url = '/features/'
+        title = '<meta property="og:title" content="Zulip Features">'
+        description = '<meta property="og:description" content="First class threading'
+        self._test(url, title, doc_html_str=True)
+        self._test(url, description, doc_html_str=True)
+
     @slow("Tests dozens of endpoints, including all our integrations docs")
     def test_integration_doc_endpoints(self) -> None:
         self._test('/integrations/',