Fix YouTube error 153 (#217)

* Fix YouTube error 153

I got YouTube error 153 on my embedded players that went away after I added `referrerpolicy="strict-origin-when-cross-origin"` to the template of embed video. This was suggested in few StackOverflow questions and it is based on https://developers.google.com/youtube/terms/required-minimum-functionality#embedded-player-api-client-identity

* Ensure that asserts include the referrerpolicy

Author: Letme

embed_video/templates/embed_video/embed_code.html

@@ -1 +1 @@
-<iframe width="{{ width }}" height="{{ height }}" src="{{ backend.url }}" loading="lazy" frameborder="0" allowfullscreen></iframe>
+<iframe width="{{ width }}" height="{{ height }}" src="{{ backend.url }}" loading="lazy" frameborder="0" allowfullscreen referrerpolicy="strict-origin-when-cross-origin"></iframe>

embed_video/tests/templatetags/tests_embed_video_tags.py

@@ -61,7 +61,7 @@ def test_embed(self):
             template,
             '<iframe width="960" height="720" '
             'src="https://www.youtube.com/embed/jsrRJyHBvzw?wmode=opaque" '
-            'loading="lazy" frameborder="0" allowfullscreen></iframe>',
+            'loading="lazy" frameborder="0" allowfullscreen referrerpolicy="strict-origin-when-cross-origin"></iframe>',
         )
 
     def test_embed_invalid_url(self):
@@ -97,7 +97,7 @@ def test_direct_embed_tag(self):
             template,
             '<iframe width="960" height="720" '
             'src="https://www.youtube.com/embed/jsrRJyHBvzw?wmode=opaque" '
-            'loading="lazy" frameborder="0" allowfullscreen></iframe>',
+            'loading="lazy" frameborder="0" allowfullscreen referrerpolicy="strict-origin-when-cross-origin"></iframe>',
         )
 
     def test_direct_embed_tag_with_default_size(self):
@@ -109,7 +109,7 @@ def test_direct_embed_tag_with_default_size(self):
             template,
             '<iframe width="480" height="360" '
             'src="https://www.youtube.com/embed/jsrRJyHBvzw?wmode=opaque" '
-            'loading="lazy" frameborder="0" allowfullscreen></iframe>',
+            'loading="lazy" frameborder="0" allowfullscreen referrerpolicy="strict-origin-when-cross-origin"></iframe>',
         )
 
     def test_direct_embed_invalid_url(self):
@@ -130,7 +130,7 @@ def test_user_size(self):
             template,
             '<iframe width="800" height="800" '
             'src="https://www.youtube.com/embed/jsrRJyHBvzw?wmode=opaque" '
-            'loading="lazy" frameborder="0" allowfullscreen></iframe>',
+            'loading="lazy" frameborder="0" allowfullscreen referrerpolicy="strict-origin-when-cross-origin"></iframe>',
         )
 
     def test_wrong_size(self):
@@ -233,7 +233,7 @@ def test_relative_size(self):
             template,
             '<iframe width="80%" height="30%" '
             'src="https://player.vimeo.com/video/72304002" '
-            'loading="lazy" frameborder="0" allowfullscreen></iframe>',
+            'loading="lazy" frameborder="0" allowfullscreen referrerpolicy="strict-origin-when-cross-origin"></iframe>',
         )
 
     def test_allow_spaces_in_size(self):
@@ -245,7 +245,7 @@ def test_allow_spaces_in_size(self):
             template,
             '<iframe width="80%" height="300" '
             'src="https://player.vimeo.com/video/72304002" '
-            'loading="lazy" frameborder="0" allowfullscreen></iframe>',
+            'loading="lazy" frameborder="0" allowfullscreen referrerpolicy="strict-origin-when-cross-origin"></iframe>',
         )
 
     def test_embed_with_query(self):
@@ -285,7 +285,7 @@ def test_direct_embed_with_query(self):
             output_without_url,
             '<iframe width="480" height="360" '
             'src="URL" '
-            'loading="lazy" frameborder="0" allowfullscreen></iframe>',
+            'loading="lazy" frameborder="0" allowfullscreen referrerpolicy="strict-origin-when-cross-origin"></iframe>',
         )
 
     def test_set_options(self):
@@ -297,7 +297,7 @@ def test_set_options(self):
             template,
             '<iframe width="300" height="200" '
             'src="https://www.youtube.com/embed/jsrRJyHBvzw?rel=1" '
-            'loading="lazy" frameborder="0" allowfullscreen></iframe>',
+            'loading="lazy" frameborder="0" allowfullscreen referrerpolicy="strict-origin-when-cross-origin"></iframe>',
         )
 
     def test_size_as_variable(self):
@@ -311,7 +311,7 @@ def test_size_as_variable(self):
             template,
             '<iframe width="500" height="200" '
             'src="https://www.youtube.com/embed/jsrRJyHBvzw?wmode=opaque" '
-            'loading="lazy" frameborder="0" allowfullscreen></iframe>',
+            'loading="lazy" frameborder="0" allowfullscreen referrerpolicy="strict-origin-when-cross-origin"></iframe>',
         )