Improve PyPI proxy test assertions for all status codes

Tests now verify the correct response for each scenario:
- 200: HTML content-type
- 404: "not found" error message
- 503: "No PyPI upstream sources configured" error message

backend/tests/integration/test_pypi_proxy.py

@@ -38,6 +38,10 @@ class TestPyPIProxyEndpoints:
             assert response.status_code in (200, 404, 503)
             if response.status_code == 200:
                 assert "text/html" in response.headers.get("content-type", "")
+            elif response.status_code == 404:
+                assert "not found" in response.json()["detail"].lower()
+            else:  # 503
+                assert "No PyPI upstream sources configured" in response.json()["detail"]
 
     @pytest.mark.integration
     def test_pypi_download_missing_upstream_param(self):
@@ -112,19 +116,21 @@ class TestPyPIPackageNormalization:
 
     @pytest.mark.integration
     def test_package_name_normalized(self):
-        """Test that package names are normalized per PEP 503."""
-        # These should all be treated the same:
-        # requests, Requests, requests_, requests-
-        # The endpoint normalizes to lowercase with hyphens
+        """Test that package names are normalized per PEP 503.
 
+        Different capitalizations/separators should all be valid paths.
+        The endpoint normalizes to lowercase with hyphens before lookup.
+        """
         with httpx.Client(base_url=get_base_url(), timeout=30.0) as client:
-            # Different capitalizations/separators should all be valid paths
-            # Returns 200/404/503 depending on sources and package availability
-            response = client.get("/pypi/simple/Requests/")
-            assert response.status_code in (200, 404, 503)
+            # Test various name formats - all should be valid endpoint paths
+            for package_name in ["Requests", "some_package", "some-package"]:
+                response = client.get(f"/pypi/simple/{package_name}/")
+                # 200 = found, 404 = not found, 503 = no sources configured
+                assert response.status_code in (200, 404, 503), \
+                    f"Unexpected status {response.status_code} for {package_name}"
 
-            response = client.get("/pypi/simple/some_package/")
-            assert response.status_code in (200, 404, 503)
-
-            response = client.get("/pypi/simple/some-package/")
-            assert response.status_code in (200, 404, 503)
+                # Verify response is appropriate for the status code
+                if response.status_code == 200:
+                    assert "text/html" in response.headers.get("content-type", "")
+                elif response.status_code == 503:
+                    assert "No PyPI upstream sources configured" in response.json()["detail"]