Add another API test, make fixtures and tests more self-consistent

jupyter_xarray_tiler/tests/fixtures/api.py

@@ -0,0 +1,24 @@
+from collections.abc import AsyncGenerator
+
+import pytest_asyncio
+
+from jupyter_xarray_tiler.titiler import _get_server
+
+
+async def _reset_titiler_api_for_testing() -> None:
+    # Shutdown the previous server
+    server = _get_server()
+    await server.stop_tile_server()
+    # Clear the cache so next time we'll get a fresh one
+    _get_server.cache_clear()
+
+
+@pytest_asyncio.fixture
+async def clean_titiler_api() -> AsyncGenerator[None]:
+    """Ensure a test's usage of the titiler API is not influenced by other tests.
+
+    I.e., the test will receive a fresh TiTiler server.
+    """
+    await _reset_titiler_api_for_testing()
+    yield
+    await _reset_titiler_api_for_testing()

jupyter_xarray_tiler/tests/fixtures/server.py

@@ -6,7 +6,7 @@
 
 
 @pytest_asyncio.fixture
-async def titiler_server() -> AsyncGenerator[TiTilerServer]:
+async def clean_titiler_server() -> AsyncGenerator[TiTilerServer]:
     server = TiTilerServer()
     await server.start_tile_server()
     yield server

jupyter_xarray_tiler/tests/test_titiler_api.py

@@ -1,14 +1,32 @@
 import pytest
+from xarray import DataArray
 
-from jupyter_xarray_tiler.titiler import _get_server, get_routes
+from jupyter_xarray_tiler.titiler import (
+    _get_server,
+    add_data_array,
+    get_routes,
+)
 
 
-def test_raises_if_get_routes_before_server_started() -> None:
+def test_singleton_ish() -> None:
+    """Test that the API only uses one TiTiler server instance."""
+    assert id(_get_server()) == id(_get_server())
+    assert _get_server() is _get_server()
+
+
+@pytest.mark.usefixtures("clean_titiler_api")
+def test_get_routes_raises_before_server_started() -> None:
     """Test that get_routes raises an error if called before initialization."""
     with pytest.raises(RuntimeError):
         get_routes()
 
 
-def test_singleton_ish() -> None:
-    """Test that the API only uses one TiTiler server instance."""
-    assert id(_get_server()) == id(_get_server())
+@pytest.mark.usefixtures("clean_titiler_api")
+async def test_add_data_array_creates_routes(
+    random_data_array: DataArray,
+) -> None:
+    await add_data_array(
+        data_array=random_data_array,
+        colormap_name="viridis",
+    )
+    assert len(get_routes()) > 0

jupyter_xarray_tiler/tests/test_titiler_server.py

@@ -12,39 +12,40 @@ async def test_server_is_not_singleton() -> None:
     Now, tests depend on being able to create a fresh instance and the end-user is
     protected from starting multiple instances in the public API.
     """
+    assert id(TiTilerServer()) != id(TiTilerServer())
     assert TiTilerServer() is not TiTilerServer()
 
 
 @pytest.mark.asyncio
 async def test_add_data_array_creates_api_routes(
-    titiler_server: TiTilerServer,
+    clean_titiler_server: TiTilerServer,
     random_data_array: DataArray,
 ) -> None:
     """Test that FastAPI routes are created when a data array is added to the server."""
-    assert len(titiler_server.routes) == 0
+    assert len(clean_titiler_server.routes) == 0
 
-    await titiler_server.add_data_array(
+    await clean_titiler_server.add_data_array(
         data_array=random_data_array,
         colormap_name="viridis",
     )
 
-    assert len(titiler_server.routes) > 1
+    assert len(clean_titiler_server.routes) > 0
 
 
 @pytest.mark.asyncio
 async def test_add_data_array_returns_valid_tile_url(
-    titiler_server: TiTilerServer,
+    clean_titiler_server: TiTilerServer,
     random_data_array: DataArray,
 ) -> None:
     """Test that adding a DataArray returns a properly formatted tile URL."""
-    tile_url = await titiler_server.add_data_array(
+    tile_url = await clean_titiler_server.add_data_array(
         data_array=random_data_array,
         colormap_name="viridis",
     )
 
     assert tile_url is not None
     assert "/proxy/" in tile_url
-    assert f"/{titiler_server._port}/" in tile_url
+    assert f"/{clean_titiler_server._port}/" in tile_url
     assert "/tiles/WebMercatorQuad/{z}/{x}/{y}.png" in tile_url
     assert "colormap_name=viridis" in tile_url
     assert "scale=1" in tile_url