test: guard fastapi-dependent modules so collection succeeds without the explorer extra

Closes #1167

tests/explorer/test_explorer_api.py

@@ -9,16 +9,15 @@ import networkx as nx
 import pytest
 
 from semantica.context.context_graph import ContextGraph
-from semantica.explorer.app import create_app
-from semantica.explorer.session import GraphSession
+# fastapi ships in the optional `explorer` extra, not in `dev`, so this module
+# must skip rather than fail collection when it is absent. The guard has to sit
+# above the import below, which pulls fastapi in transitively.
+pytest.importorskip("fastapi")
 
-try:
-    from starlette.testclient import TestClient
-except ImportError:
-    pytest.skip(
-        "starlette TestClient is required for explorer tests. Install semantica[explorer].",
-        allow_module_level=True,
-    )
+from semantica.explorer.app import create_app  # noqa: E402
+from semantica.explorer.session import GraphSession  # noqa: E402
+
+from starlette.testclient import TestClient  # noqa: E402
 
 
 
@@ -1104,7 +1103,7 @@ class TestBidirectionalPathRoute:
 # _classify_distance unit tests — issue #472
 # ---------------------------------------------------------------------------
 
-from semantica.utils.helpers import classify_path_distance
+from semantica.utils.helpers import classify_path_distance  # noqa: E402
 
 
 class _FakeSimilarity:

tests/explorer/test_explorer_auth.py

@@ -13,16 +13,15 @@ browsers can't set custom headers on a WebSocket handshake.
 import pytest
 
 from semantica.context.context_graph import ContextGraph
-from semantica.explorer.app import create_app
-from semantica.explorer.session import GraphSession
+# fastapi ships in the optional `explorer` extra, not in `dev`, so this module
+# must skip rather than fail collection when it is absent. The guard has to sit
+# above the import below, which pulls fastapi in transitively.
+pytest.importorskip("fastapi")
 
-try:
-    from starlette.testclient import TestClient
-except ImportError:
-    pytest.skip(
-        "starlette TestClient is required for explorer tests. Install semantica[explorer].",
-        allow_module_level=True,
-    )
+from semantica.explorer.app import create_app  # noqa: E402
+from semantica.explorer.session import GraphSession  # noqa: E402
+
+from starlette.testclient import TestClient  # noqa: E402
 
 
 def _build_sample_graph() -> ContextGraph:

tests/explorer/test_ontology_dns_pinning.py

@@ -27,7 +27,12 @@ import threading
 
 import pytest
 
-from semantica.explorer.routes import ontology as ontology_mod
+# fastapi ships in the optional `explorer` extra, not in `dev`, so this module
+# must skip rather than fail collection when it is absent. The guard has to sit
+# above the import below, which pulls fastapi in transitively.
+pytest.importorskip("fastapi")
+
+from semantica.explorer.routes import ontology as ontology_mod  # noqa: E402
 
 
 def _start_local_server():

tests/explorer/test_ontology_ssrf.py

@@ -21,7 +21,12 @@ from unittest.mock import MagicMock, patch
 
 import pytest
 
-from semantica.explorer.routes import ontology as ontology_mod
+# fastapi ships in the optional `explorer` extra, not in `dev`, so this module
+# must skip rather than fail collection when it is absent. The guard has to sit
+# above the import below, which pulls fastapi in transitively.
+pytest.importorskip("fastapi")
+
+from semantica.explorer.routes import ontology as ontology_mod  # noqa: E402
 
 
 def _fake_getaddrinfo(host, *args, **kwargs):

tests/explorer/test_ontology_subissue3.py

@@ -6,17 +6,16 @@ from urllib.parse import quote
 import pytest
 
 from semantica.context.context_graph import ContextGraph
-from semantica.explorer.app import create_app
-from semantica.explorer.routes.ontology import OntologyEntry
-from semantica.explorer.session import GraphSession
+# fastapi ships in the optional `explorer` extra, not in `dev`, so this module
+# must skip rather than fail collection when it is absent. The guard has to sit
+# above the import below, which pulls fastapi in transitively.
+pytest.importorskip("fastapi")
 
-try:
-    from starlette.testclient import TestClient
-except ImportError:
-    pytest.skip(
-        "starlette TestClient is required for explorer tests. Install semantica[explorer].",
-        allow_module_level=True,
-    )
+from semantica.explorer.app import create_app  # noqa: E402
+from semantica.explorer.routes.ontology import OntologyEntry  # noqa: E402
+from semantica.explorer.session import GraphSession  # noqa: E402
+
+from starlette.testclient import TestClient  # noqa: E402
 
 
 def _build_ontology_graph() -> ContextGraph:

tests/explorer/test_provenance_manager_wiring.py

@@ -5,13 +5,18 @@ Tests for ProvenanceManager wiring into Explorer routes and application startup.
 from unittest.mock import patch
 
 import pytest
-from starlette.testclient import TestClient
+# fastapi ships in the optional `explorer` extra, not in `dev`, so this module
+# must skip rather than fail collection when it is absent. The guard has to sit
+# above the starlette/explorer imports below, which need that extra.
+pytest.importorskip("fastapi")
 
-from semantica.context.context_graph import ContextGraph
-from semantica.explorer.app import create_app
-from semantica.explorer.session import GraphSession
-from semantica.provenance import ProvenanceManager
-from semantica.provenance.storage import SQLiteStorage
+from starlette.testclient import TestClient  # noqa: E402
+
+from semantica.context.context_graph import ContextGraph  # noqa: E402
+from semantica.explorer.app import create_app  # noqa: E402
+from semantica.explorer.session import GraphSession  # noqa: E402
+from semantica.provenance import ProvenanceManager  # noqa: E402
+from semantica.provenance.storage import SQLiteStorage  # noqa: E402
 
 
 @pytest.fixture

tests/explorer/test_provenance_route.py

@@ -2,7 +2,14 @@
 
 from types import SimpleNamespace
 
-from semantica.explorer.routes.provenance import (
+import pytest
+
+# fastapi ships in the optional `explorer` extra, not in `dev`, so this module
+# must skip rather than fail collection when it is absent. The guard has to sit
+# above the import below, which pulls fastapi in transitively.
+pytest.importorskip("fastapi")
+
+from semantica.explorer.routes.provenance import (  # noqa: E402
     _add_chain_edges,
     _build_provenance,
     _render_markdown,

tests/explorer/test_sparql_route.py

@@ -14,18 +14,17 @@ from unittest.mock import patch
 import pytest
 
 from semantica.context.context_graph import ContextGraph
-from semantica.explorer.app import create_app
-from semantica.explorer.session import GraphSession
+# fastapi ships in the optional `explorer` extra, not in `dev`, so this module
+# must skip rather than fail collection when it is absent. The guard has to sit
+# above the import below, which pulls fastapi in transitively.
+pytest.importorskip("fastapi")
 
-try:
-    from starlette.testclient import TestClient
-except ImportError:
-    pytest.skip(
-        "starlette TestClient is required for explorer tests. Install semantica[explorer].",
-        allow_module_level=True,
-    )
+from semantica.explorer.app import create_app  # noqa: E402
+from semantica.explorer.session import GraphSession  # noqa: E402
 
-import semantica.explorer.routes.sparql as sparql_mod
+from starlette.testclient import TestClient  # noqa: E402
+
+import semantica.explorer.routes.sparql as sparql_mod  # noqa: E402
 
 
 def _build_sample_graph() -> ContextGraph:

tests/explorer/test_vocabulary.py

@@ -2,12 +2,19 @@
 
 from unittest.mock import MagicMock
 
-from fastapi import FastAPI
-from fastapi.testclient import TestClient
+import pytest
 
-from semantica.explorer.dependencies import get_session
-from semantica.explorer.routes.vocabulary import router
-from semantica.utils.skos import validate_skos_hierarchy
+# fastapi ships in the optional `explorer` extra, not in `dev`, so this module
+# must skip rather than fail collection when it is absent. The guard has to sit
+# above the import below, which pulls fastapi in transitively.
+pytest.importorskip("fastapi")
+
+from fastapi import FastAPI  # noqa: E402
+from fastapi.testclient import TestClient  # noqa: E402
+
+from semantica.explorer.dependencies import get_session  # noqa: E402
+from semantica.explorer.routes.vocabulary import router  # noqa: E402
+from semantica.utils.skos import validate_skos_hierarchy  # noqa: E402
 
 app = FastAPI()
 app.include_router(router)

tests/test_security_regression.py

@@ -24,7 +24,12 @@ import pytest
 # rdf:/rdfs: namespaces) and neither the code nor this test caught it,
 # since both had the same bug. Importing the real function makes that class
 # of drift impossible.
-from semantica.explorer.routes.sparql import _is_read_only_query
+# fastapi ships in the optional `explorer` extra, not in `dev`, so this module
+# must skip rather than fail collection when it is absent. The guard has to sit
+# above the import below, which pulls fastapi in transitively.
+pytest.importorskip("fastapi")
+
+from semantica.explorer.routes.sparql import _is_read_only_query  # noqa: E402
 
 
 class TestSparqlReadOnlyValidation: