Issue webcompat#609 - Implement Cache-Policy decorator

Issue webcompat#609 - Removes code dust

tests/test_http_caching.py

@@ -0,0 +1,69 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+'''Tests for HTTP Caching on webcompat resources.'''
+
+import os.path
+import sys
+import unittest
+
+# Add webcompat module to import path
+sys.path.append(os.path.realpath(os.pardir))
+import webcompat  # nopep8
+
+# Any request that depends on parsing HTTP Headers (basically anything
+# on the index route, will need to include the following: environ_base=headers
+html_headers = {
+    'HTTP_USER_AGENT': ('Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; '
+                        'rv:53.0) Gecko/20100101 Firefox/53.0'),
+    'HTTP_ACCEPT': 'text/html'}
+
+
+class TestHTTPCaching(unittest.TestCase):
+    def setUp(self):
+        webcompat.app.config['TESTING'] = True
+        self.app = webcompat.app.test_client()
+
+    def tearDown(self):
+        pass
+
+    def test_issue_has_etag(self):
+        '''Check ETAG for issues.'''
+        rv = self.app.get('/issues/100', environ_base=html_headers)
+        response_headers = rv.headers
+        self.assertIn('etag', response_headers)
+        self.assertIsNotNone(response_headers['etag'])
+
+    def test_cache_control(self):
+        '''Check Cache-Control for issues.'''
+        rv = self.app.get('/issues/100', environ_base=html_headers)
+        response_headers = rv.headers
+        self.assertIn('cache-control', response_headers)
+        self.assertEqual(response_headers['cache-control'],
+                         'private, max-age=86400')
+
+    def test_not_modified_status(self):
+        '''Checks if we receive a 304 Not Modified.'''
+        for uri in ['/about',
+                    '/contributors',
+                    '/issues',
+                    '/issues/100',
+                    '/privacy']:
+            rv = self.app.get(uri, environ_base=html_headers)
+            response_headers = rv.headers
+            etag = response_headers['etag']
+            rv2 = self.app.get(uri,
+                               environ_base=html_headers,
+                               headers={'If-None-Match': etag})
+            self.assertEqual(rv2.status_code, 304)
+            self.assertEqual(rv2.data, '')
+            self.assertIn('cache-control', response_headers)
+            self.assertEqual(response_headers['cache-control'],
+                             'private, max-age=86400')
+
+
+if __name__ == '__main__':
+    unittest.main()

webcompat/api/endpoints.py

@@ -9,7 +9,6 @@
 This is used to make API calls to GitHub, either via a logged-in users
 credentials or as a proxy on behalf of anonymous or unauthenticated users.'''
 
-import json
 
 from flask import abort
 from flask import Blueprint

webcompat/helpers.py

@@ -5,6 +5,8 @@
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 from datetime import datetime
+from functools import wraps
+from functools import update_wrapper
 import hashlib
 import json
 import math
@@ -16,10 +18,10 @@
 from babel.dates import format_timedelta
 from flask import abort
 from flask import g
+from flask import make_response
 from flask import request
 from flask import session
 from form import IssueForm
-from functools import wraps
 from ua_parser import user_agent_parser
 
 from webcompat import app
@@ -456,3 +458,32 @@ def api_request(method, path, params=None, data=None):
                 get_response_headers(resource))
     else:
         abort(404)
+
+
+def cache_policy(private=True, uri_max_age=86400):
+    '''Implements a HTTP Cache Decorator.
+
+    Adds Cache-Control headers.
+      * max-age has a 1 day default (86400s)
+      * and makes it private by default
+    Adds Etag based on HTTP Body.
+    Sends a 304 Not Modified in case of If-None-Match.
+    '''
+    def set_policy(view):
+        @wraps(view)
+        def policy(*args, **kwargs):
+            response = make_response(view(*args, **kwargs))
+            # we choose if the resource is private or public
+            if private:
+                response.cache_control.private = True
+            else:
+                response.cache_control.public = True
+            # Instructs how long the Cache should keep the resource
+            response.cache_control.max_age = uri_max_age
+            # Etag is based on the HTTP body
+            response.add_etag(response.data)
+            # to send a 304 Not Modified instead of a full HTTP response
+            response.make_conditional(request)
+            return response
+        return update_wrapper(policy, view)
+    return set_policy

webcompat/views.py

@@ -7,11 +7,11 @@
 import json
 import logging
 import os
-import urllib
 
 from flask import abort
 from flask import flash
 from flask import g
+from flask import make_response
 from flask import redirect
 from flask import render_template
 from flask import request
@@ -21,6 +21,7 @@
 
 from form import AUTH_REPORT
 from form import PROXY_REPORT
+from helpers import cache_policy
 from helpers import get_browser_name
 from helpers import get_form
 from helpers import get_referer
@@ -143,6 +144,7 @@ def index():
 
 
 @app.route('/issues')
+@cache_policy(private=True, uri_max_age=86400)
 def show_issues():
     '''Route to display global issues view.'''
     if g.user:
@@ -152,6 +154,7 @@ def show_issues():
 
 
 @app.route('/issues/new', methods=['GET', 'POST'])
+@cache_policy(private=True, uri_max_age=86400)
 def create_issue():
     """Creates a new issue.
 
@@ -201,14 +204,17 @@ def create_issue():
 
 
 @app.route('/issues/<int:number>')
+@cache_policy(private=True, uri_max_age=86400)
 def show_issue(number):
     '''Route to display a single issue.'''
     if g.user:
         get_user_info()
     if session.get('show_thanks'):
         flash(number, 'thanks')
         session.pop('show_thanks')
-    return render_template('issue.html', number=number)
+    content = render_template('issue.html', number=number)
+    response = make_response(content)
+    return response
 
 
 @app.route('/me')
@@ -279,6 +285,7 @@ def get_test_helper(filename):
 
 
 @app.route('/about')
+@cache_policy(private=True, uri_max_age=86400)
 def about():
     '''Route to display about page.'''
     if g.user:
@@ -287,6 +294,7 @@ def about():
 
 
 @app.route('/privacy')
+@cache_policy(private=True, uri_max_age=86400)
 def privacy():
     '''Route to display privacy page.'''
     if g.user:
@@ -295,6 +303,7 @@ def privacy():
 
 
 @app.route('/contributors')
+@cache_policy(private=True, uri_max_age=86400)
 def contributors():
     '''Route to display contributors page.'''
     if g.user: