add middleware to add signposting links into html head (#3)

* add middleware to add signposting links into html head
2026-09-10 22:15:30 +00:00 · 2024-11-25 15:44:46 +01:00
parent 06d745e4a4
commit b29f19d78a
6 changed files with 530 additions and 3 deletions
--- a/tests/test_html_signposting_middleware.py
+++ b/tests/test_html_signposting_middleware.py
@@ -0,0 +1,112 @@
+from bs4 import BeautifulSoup
+from django.http import HttpResponse, JsonResponse
+from django_signposting.middleware import HtmlSignpostingMiddleware
+from signposting import LinkRel, Signpost
+import pytest
+
+
+def assert_links_exist(response: HttpResponse, signposts: list[Signpost] = None):
+    if signposts is None:
+        signposts = response._signposts
+
+    soup = BeautifulSoup(response.content.decode("utf-8"), "html.parser")
+    for signpost in signposts:
+        links = soup.find_all("link", href=signpost.target, rel=signpost.rel)
+        assert len(links) == 1
+
+    assert len(soup.find_all("link")) == len(signposts)
+
+
+def test_middleware_no_signposting():
+    response = HttpResponse("<html><head></head><body></body></html>")
+    response.status_code = 200
+
+    middleware = HtmlSignpostingMiddleware(lambda request: response)
+    response = middleware(None)
+
+    assert_links_exist(response, [])
+
+
+def test_middleware_no_html():
+    response = JsonResponse({"hello": "world"})
+    response.status_code = 200
+    response._signpost = [Signpost(LinkRel.author, "http://example.com")]
+
+    middleware = HtmlSignpostingMiddleware(lambda request: response)
+    middleware(None)
+    assert_links_exist(response, [])
+
+
+def test_middleware_malformed_html():
+    response = HttpResponse("Hello world")
+    response.status_code = 200
+    response.content_type = "text/html"
+    response._signposts = [Signpost(LinkRel.author, "http://example.com")]
+
+    middleware = HtmlSignpostingMiddleware(lambda request: response)
+    with pytest.raises(Exception):
+        middleware(None)
+
+
+def test_middleware_signposting_without_head():
+    response = HttpResponse("<html><body></body></html>")
+    response.status_code = 200
+    response._signposts = [Signpost(LinkRel.author, "http://example.com")]
+
+    middleware = HtmlSignpostingMiddleware(lambda request: response)
+    middleware(None)
+    assert_links_exist(response)
+
+
+def test_middleware_signposting():
+    response = HttpResponse("<html><head></head><body></body></html>")
+    response.status_code = 200
+    response._signposts = [Signpost(LinkRel.author, "http://example.com")]
+
+    middleware = HtmlSignpostingMiddleware(lambda request: response)
+    middleware(None)
+    assert_links_exist(response)
+
+
+def test_middleware_multiple_signposts():
+    response = HttpResponse("<html><head></head><body></body></html>")
+    response.status_code = 200
+    response._signposts = [
+        Signpost(LinkRel.author, "http://example.com"),
+        Signpost(LinkRel.author, "http://example2.com"),
+        Signpost(LinkRel.cite_as, "http://example3.com"),
+    ]
+
+    middleware = HtmlSignpostingMiddleware(lambda request: response)
+    response = middleware(None)
+    assert_links_exist(response)
+
+
+def test_middleware_signpost_with_content_type():
+    response = HttpResponse("<html><head></head><body></body></html>")
+    response.status_code = 200
+    response._signposts = [Signpost(LinkRel.item, "http://example.com", "text/json")]
+
+    middleware = HtmlSignpostingMiddleware(lambda request: response)
+    response = middleware(None)
+    assert_links_exist(response)
+
+
+def test_middleware_ignore_error_responses():
+    response = HttpResponse("<html><head></head><body></body></html>")
+    response.status_code = 400
+    response._signposts = [Signpost(LinkRel.author, "http://example.com")]
+
+    middleware = HtmlSignpostingMiddleware(lambda request: response)
+    response = middleware(None)
+    assert_links_exist(response)
+
+
+def test_middleware_type_link():
+    response = HttpResponse("<html><head></head><body></body></html>")
+    response.status_code = 200
+    response._signposts = [Signpost(LinkRel.type, "http://schema.org/Dataset")]
+
+    middleware = HtmlSignpostingMiddleware(lambda request: response)
+    response = middleware(None)
+    assert_links_exist(response)