fix: resolve all FT lint violations and install pre-commit hook

Install the flagsmith-lint-tests hook in pre-commit config and fix all
existing FT003/FT004 violations across the test suite by renaming tests
to test_{subject}__{condition}__{expected} and adding Given/When/Then
comments.

Author: khvn26

.pre-commit-config.yaml

@@ -20,6 +20,12 @@ repos:
       - id: check-toml
   - repo: local
     hooks:
+      - id: flagsmith-lint-tests
+        name: flagsmith-lint-tests
+        language: system
+        entry: python -P src/common/lint_tests.py
+        types: [python]
+        files: ^tests/.*test_.*\.py$
       - id: python-typecheck
         name: python-typecheck
         language: system

…pshots/test_metrics__return_expected.txt …s__default_request__returns_expected.txttests/integration/core/snapshots/test_metrics__return_expected.txt renamed to tests/integration/core/snapshots/test_metrics__default_request__returns_expected.txt tests/integration/core/snapshots/test_metrics__return_expected.txt renamed to tests/integration/core/snapshots/test_metrics__default_request__returns_expected.txt

@@ -1,3 +1,3 @@
 # HELP pytest_tests_run_total Total number of tests run by pytest.
 # TYPE pytest_tests_run_total counter
-pytest_tests_run_total{test_name="test_metrics__return_expected"} 1.0
+pytest_tests_run_total{test_name="test_metrics__default_request__returns_expected"} 1.0

tests/integration/core/test_main.py

@@ -35,7 +35,7 @@ def test_main__non_overridden_args__defaults_to_django(
         ["flagsmith", "healthcheck", "tcp"],
     ),
 )
-def test_main__healthcheck_tcp__no_server__runs_expected(
+def test_main__healthcheck_tcp_no_server__runs_expected(
     argv: list[str],
     capsys: pytest.CaptureFixture[str],
 ) -> None:
@@ -48,7 +48,7 @@ def test_main__healthcheck_tcp__no_server__runs_expected(
     assert exc_info.value.code == 1
 
 
-def test_main__healthcheck_tcp__server__runs_expected(
+def test_main__healthcheck_tcp_server__runs_expected(
     unused_tcp_port: int,
     http_server: HTTPServer,
 ) -> None:
@@ -63,7 +63,7 @@ def test_main__healthcheck_tcp__server__runs_expected(
     assert exc_info.value.code == 0
 
 
-def test_main__healthcheck_http__no_server__runs_expected() -> None:
+def test_main__healthcheck_http_no_server__runs_expected() -> None:
     # Given
     argv = ["flagsmith", "healthcheck", "http"]
 
@@ -79,7 +79,7 @@ def test_main__healthcheck_http__no_server__runs_expected() -> None:
         (["flagsmith", "healthcheck", "http", "health/readiness"], "/health/readiness"),
     ),
 )
-def test_main__healthcheck_http__server__runs_expected(
+def test_main__healthcheck_http_server__runs_expected(
     unused_tcp_port: int,
     http_server: HTTPServer,
     argv: list[str],
@@ -94,7 +94,7 @@ def test_main__healthcheck_http__server__runs_expected(
     main(argv)
 
 
-def test_main__healthcheck_http__server_invalid_response__runs_expected(
+def test_main__healthcheck_http_server_invalid_response__runs_expected(
     unused_tcp_port: int,
     http_server: HTTPServer,
 ) -> None:

tests/integration/core/test_views.py

@@ -5,26 +5,34 @@
 from common.test_tools import SnapshotFixture
 
 
-def test_liveness_probe__return_expected(
+def test_liveness_probe__default_request__returns_expected(
     client: APIClient,
 ) -> None:
-    response = client.get("/health/liveness/")
+    # Given
+    url = "/health/liveness/"
+
+    # When
+    response = client.get(url)
+
+    # Then
     assert response.status_code == 200
     assert response.json() == {"status": "ok"}
 
 
 @pytest.mark.prometheus_multiprocess_mode
-def test_metrics__return_expected(
+def test_metrics__default_request__returns_expected(
     test_metric: prometheus_client.Counter,
     client: APIClient,
     snapshot: SnapshotFixture,
 ) -> None:
-    # Arrange
-    test_metric.labels(test_name="test_metrics__return_expected").inc()
+    # Given
+    test_metric.labels(
+        test_name="test_metrics__default_request__returns_expected"
+    ).inc()
 
-    # Act
+    # When
     response = client.get("/metrics", follow=True)
 
-    # Assert
+    # Then
     assert response.status_code == 200
     assert response.content.decode() == snapshot()

tests/integration/flagsmith_schemas/test_dynamodb.py

@@ -966,7 +966,7 @@ def test_document__validate_json__expected_result(
     assert document == expected_result
 
 
-def test_type_adapter__identity__duplicate_features__raises_expected(
+def test_type_adapter__identity_duplicate_features__raises_expected(
     mocker: MockerFixture,
 ) -> None:
     # Given
@@ -1009,7 +1009,7 @@ def test_type_adapter__identity__duplicate_features__raises_expected(
     )
 
 
-def test_type_adapter__environment__multivariate_feature_states_percentage_allocation_exceeds_100__raises_expected() -> (
+def test_type_adapter__environment_multivariate_feature_states_percentage_allocation_exceeds_100__raises_expected() -> (
     None
 ):
     # Given

tests/unit/common/core/test_logging.py

@@ -8,7 +8,7 @@
 
 
 @pytest.mark.freeze_time("2023-12-08T06:05:47+00:00")
-def test_json_formatter__outputs_expected(
+def test_json_formatter__format_log__outputs_expected(
     caplog: pytest.LogCaptureFixture,
     request: pytest.FixtureRequest,
 ) -> None:

tests/unit/common/core/test_middleware.py

@@ -3,7 +3,7 @@
 from common.core import middleware as middleware_module
 
 
-def test_APIResponseVersionHeaderMiddleware__adds_version_header(
+def test_api_response_version_header_middleware__request_processed__adds_version_header(
     mocker: MockerFixture,
 ) -> None:
     # Given

tests/unit/common/core/test_utils.py

@@ -49,28 +49,33 @@ def bad_replica(mocker: MockerFixture) -> MockType:
     return replica
 
 
-def test__is_oss_for_enterprise_returns_false(fs: FakeFilesystem) -> None:
+def test_is_oss__enterprise_version_exists__returns_false(fs: FakeFilesystem) -> None:
     # Given
     fs.create_file("./ENTERPRISE_VERSION")
 
-    # Then
+    # When / Then
     assert is_oss() is False
 
 
-def test__is_oss_for_saas_returns_false(fs: FakeFilesystem) -> None:
+def test_is_oss__saas_deployment_exists__returns_false(fs: FakeFilesystem) -> None:
     # Given
     fs.create_file("./SAAS_DEPLOYMENT")
 
-    # Then
+    # When / Then
     assert is_oss() is False
 
 
-def test__is_oss_for_oss_returns_true(fs: FakeFilesystem) -> None:
+def test_is_oss__no_version_files__returns_true(fs: FakeFilesystem) -> None:
+    # Given / When
+    result = is_oss()
+
     # Then
-    assert is_oss() is True
+    assert result is True
 
 
-def test_get_version_info(fs: FakeFilesystem) -> None:
+def test_get_version_info__all_files_present__returns_expected(
+    fs: FakeFilesystem,
+) -> None:
     # Given
     expected_manifest_contents = {
         ".": "2.66.2",
@@ -98,7 +103,7 @@ def test_get_version_info(fs: FakeFilesystem) -> None:
     }
 
 
-def test_get_version_info_with_missing_files(fs: FakeFilesystem) -> None:
+def test_get_version_info__missing_files__returns_unknown(fs: FakeFilesystem) -> None:
     # Given
     fs.create_file("./ENTERPRISE_VERSION")
 
@@ -217,7 +222,7 @@ def test_get_version__invalid_file_contents__returns_unknown(
         ({"default", "replica_1", "cross_region_replica_1"}, True),
     ],
 )
-def test_is_database_replica_setup__tells_whether_any_replica_is_present(
+def test_is_database_replica_setup__various_database_configs__returns_expected(
     database_names: list[str],
     expected: bool,
     mocker: MockerFixture,

tests/unit/common/gunicorn/test_conf.py

@@ -6,7 +6,7 @@
 from common.gunicorn.conf import child_exit, when_ready
 
 
-def test_child_exit__calls_mark_process_dead_with_worker_pid(
+def test_child_exit__worker_exits__marks_process_dead_with_worker_pid(
     mocker: MockerFixture,
 ) -> None:
     # Given

tests/unit/common/gunicorn/test_logging.py

@@ -17,7 +17,7 @@
 
 
 @pytest.mark.freeze_time("2023-12-08T06:05:47+00:00")
-def test_gunicorn_access_log_json_formatter__outputs_expected(
+def test_gunicorn_access_log_json_formatter__format_log__outputs_expected(
     settings: SettingsWrapper,
 ) -> None:
     # Given
@@ -97,7 +97,7 @@ def test_gunicorn_access_log_json_formatter__outputs_expected(
     }
 
 
-def test_gunicorn_prometheus_gunicorn_logger__expected_metrics(
+def test_gunicorn_prometheus_gunicorn_logger__access_logged__expected_metrics(
     mocker: MockerFixture,
     assert_metric: AssertMetricFixture,
 ) -> None:
@@ -136,7 +136,7 @@ def test_gunicorn_prometheus_gunicorn_logger__expected_metrics(
     )
 
 
-def test_gunicorn_json_capable_logger__sets_expected_formatters(
+def test_gunicorn_json_capable_logger__json_log_format__sets_expected_formatters(
     settings: SettingsWrapper,
 ) -> None:
     # Given