add middleware for signposts

tests/test_middleware.py

@@ -0,0 +1,75 @@
+from django.http import HttpResponse, HttpRequest
+from django.conf import settings
+from django_signposting.middleware import SignpostingMiddleware
+import pytest
+
+
+@pytest.fixture(scope="module", autouse=True)
+def configure_django_settings():
+    settings.configure()
+
+
+def test_middleware_no_signposting():
+    response = HttpResponse()
+    response.status_code = 200
+
+    middleware = SignpostingMiddleware(lambda request: response)
+    response = middleware(None)
+    assert "Link" not in response.headers
+
+
+def test_middleware_signposting():
+    response = HttpResponse()
+    response.status_code = 200
+    response._signposts = {"author": ["http://example.com"]}
+
+    middleware = SignpostingMiddleware(lambda request: response)
+    response = middleware(None)
+    assert response.headers["Link"] == '<http://example.com> ; rel="author"'
+
+
+def test_middleware_multiple_signposts():
+    response = HttpResponse()
+    response.status_code = 200
+    response._signposts = {
+        "author": [
+            "http://example.com",
+            "http://example2.com"
+        ],
+        "cite-as": [
+            "http://example3.com"
+        ]
+    }
+
+    middleware = SignpostingMiddleware(lambda request: response)
+    response = middleware(None)
+    links = [x.strip() for x in response.headers["Link"].split(",")]
+    assert '<http://example.com> ; rel="author"' in links
+    assert '<http://example2.com> ; rel="author"' in links
+    assert '<http://example3.com> ; rel="cite-as"' in links
+
+
+def test_middleware_signpost_with_content_type():
+    response = HttpResponse()
+    response.status_code = 200
+    response._signposts = {
+        "item": [
+            ("http://example.com", "test/json"),
+        ]
+    }
+
+    middleware = SignpostingMiddleware(lambda request: response)
+    response = middleware(None)
+    assert response.headers["Link"] == '<http://example.com> ; rel="item" ; type="test/json"'
+
+
+def test_middleware_ignore_error_responses():
+    response = HttpResponse()
+    response.status_code = 400
+    response._signposts = {
+        "author": ["https://example.com"]
+    }
+
+    middleware = SignpostingMiddleware(lambda request: response)
+    response = middleware(None)
+    assert "Link" not in response.headers