Add option for showing bookmark favicons (#390)

* Implement favicon loader

* Implement load favicon task

* Show favicons in bookmark list

* Add missing migration

* Load missing favicons on import

* Automatically refresh favicons

* Add enable favicon setting

* Update uwsgi config to host favicons

* Improve settings wording

* Fix favicon loader test setup

* Document LD_FAVICON_PROVIDER setting

* Add refresh favicons button

bookmarks/tests/test_favicon_loader.py

@@ -0,0 +1,127 @@
+import io
+import os.path
+import time
+from pathlib import Path
+from unittest import mock
+
+from django.conf import settings
+from django.test import TestCase
+
+from bookmarks.services import favicon_loader
+
+mock_icon_data = b'mock_icon'
+
+
+class FaviconLoaderTestCase(TestCase):
+    def setUp(self) -> None:
+        self.ensure_favicon_folder()
+        self.clear_favicon_folder()
+
+    def create_mock_response(self, icon_data=mock_icon_data):
+        mock_response = mock.Mock()
+        mock_response.raw = io.BytesIO(icon_data)
+        return mock_response
+
+    def ensure_favicon_folder(self):
+        Path(settings.LD_FAVICON_FOLDER).mkdir(parents=True, exist_ok=True)
+
+    def clear_favicon_folder(self):
+        folder = Path(settings.LD_FAVICON_FOLDER)
+        for file in folder.iterdir():
+            file.unlink()
+
+    def get_icon_path(self, filename):
+        return Path(os.path.join(settings.LD_FAVICON_FOLDER, filename))
+
+    def icon_exists(self, filename):
+        return self.get_icon_path(filename).exists()
+
+    def get_icon_data(self, filename):
+        return self.get_icon_path(filename).read_bytes()
+
+    def count_icons(self):
+        files = os.listdir(settings.LD_FAVICON_FOLDER)
+        return len(files)
+
+    def test_load_favicon(self):
+        with mock.patch('requests.get') as mock_get:
+            mock_get.return_value = self.create_mock_response()
+            favicon_loader.load_favicon('https://example.com')
+
+            # should create icon file
+            self.assertTrue(self.icon_exists('https_example_com.png'))
+
+            # should store image data
+            self.assertEqual(mock_icon_data, self.get_icon_data('https_example_com.png'))
+
+    def test_load_favicon_creates_folder_if_not_exists(self):
+        with mock.patch('requests.get') as mock_get:
+            mock_get.return_value = self.create_mock_response()
+
+            folder = Path(settings.LD_FAVICON_FOLDER)
+            folder.rmdir()
+
+            self.assertFalse(folder.exists())
+
+            favicon_loader.load_favicon('https://example.com')
+
+            self.assertTrue(folder.exists())
+
+    def test_load_favicon_creates_single_icon_for_same_base_url(self):
+        with mock.patch('requests.get') as mock_get:
+            mock_get.return_value = self.create_mock_response()
+            favicon_loader.load_favicon('https://example.com')
+            favicon_loader.load_favicon('https://example.com?foo=bar')
+            favicon_loader.load_favicon('https://example.com/foo')
+
+            self.assertEqual(1, self.count_icons())
+            self.assertTrue(self.icon_exists('https_example_com.png'))
+
+    def test_load_favicon_creates_multiple_icons_for_different_base_url(self):
+        with mock.patch('requests.get') as mock_get:
+            mock_get.return_value = self.create_mock_response()
+            favicon_loader.load_favicon('https://example.com')
+            favicon_loader.load_favicon('https://sub.example.com')
+            favicon_loader.load_favicon('https://other-domain.com')
+
+            self.assertEqual(3, self.count_icons())
+            self.assertTrue(self.icon_exists('https_example_com.png'))
+            self.assertTrue(self.icon_exists('https_sub_example_com.png'))
+            self.assertTrue(self.icon_exists('https_other_domain_com.png'))
+
+    def test_load_favicon_caches_icons(self):
+        with mock.patch('requests.get') as mock_get:
+            mock_get.return_value = self.create_mock_response()
+
+            favicon_loader.load_favicon('https://example.com')
+            mock_get.assert_called()
+
+            mock_get.reset_mock()
+            favicon_loader.load_favicon('https://example.com')
+            mock_get.assert_not_called()
+
+    def test_load_favicon_updates_stale_icon(self):
+        with mock.patch('requests.get') as mock_get:
+            mock_get.return_value = self.create_mock_response()
+            favicon_loader.load_favicon('https://example.com')
+
+            icon_path = self.get_icon_path('https_example_com.png')
+
+            updated_mock_icon_data = b'updated_mock_icon'
+            mock_get.return_value = self.create_mock_response(icon_data=updated_mock_icon_data)
+            mock_get.reset_mock()
+
+            # change icon modification date so it is not stale yet
+            nearly_one_day_ago = time.time() - 60 * 60 * 23
+            os.utime(icon_path.absolute(), (nearly_one_day_ago, nearly_one_day_ago))
+
+            favicon_loader.load_favicon('https://example.com')
+            mock_get.assert_not_called()
+
+            # change icon modification date so it is considered stale
+            one_day_ago = time.time() - 60 * 60 * 24
+            os.utime(icon_path.absolute(), (one_day_ago, one_day_ago))
+
+            favicon_loader.load_favicon('https://example.com')
+            mock_get.assert_called()
+            self.assertEqual(updated_mock_icon_data, self.get_icon_data('https_example_com.png'))