Add tests for the API prefix and use it.

The previous commit laid the groundwork but failed to actually set the API prefix. This is now fixed.

The API prefix is tested in a couple of places: validation is tested in `test_server_config_model`, and the endpoints are checked in `test_server` explicitly, and `test_thing_client` implicitly (because we use a prefix for the thing that's tested).

Author: rwb27

src/labthings_fastapi/server/__init__.py

@@ -94,6 +94,7 @@ def __init__(
         self._config = ThingServerConfig(
             things=things,
             settings_folder=settings_folder,
+            api_prefix=api_prefix,
             application_config=application_config,
         )
         self.app = FastAPI(lifespan=self.lifespan)

src/labthings_fastapi/server/config_model.py

@@ -182,7 +182,7 @@ def thing_configs(self) -> Mapping[ThingName, ThingConfig]:
 
     api_prefix: str = Field(
         default="",
-        pattern="(\/[\w-]+)*",
+        pattern=r"^(\/[\w-]+)*$",
         description=(
             """A prefix added to all endpoints, including Things.
 

tests/test_server.py

@@ -7,6 +7,7 @@
 import pytest
 import labthings_fastapi as lt
 from fastapi.testclient import TestClient
+from starlette.routing import Route
 
 
 def test_server_from_config_non_thing_error():
@@ -63,3 +64,31 @@ def test_server_thing_descriptions():
             prop = thing_description["properties"][prop_name]
             expected_href = thing_name + "/" + prop_name
             assert prop["forms"][0]["href"] == expected_href
+
+
+def test_api_prefix():
+    """Check we can add a prefix to the URLs on a server."""
+
+    class Example(lt.Thing):
+        """An example Thing"""
+
+    server = lt.ThingServer(things={"example": Example}, api_prefix="/api/v3")
+    paths = [route.path for route in server.app.routes if isinstance(route, Route)]
+    for expected_path in [
+        "/api/v3/action_invocations",
+        "/api/v3/action_invocations/{id}",
+        "/api/v3/action_invocations/{id}/output",
+        "/api/v3/action_invocations/{id}",
+        "/api/v3/blob/{blob_id}",
+        "/api/v3/thing_descriptions/",
+        "/api/v3/example/",
+    ]:
+        assert expected_path in paths
+
+    unprefixed_paths = {p for p in paths if not p.startswith("/api/v3/")}
+    assert unprefixed_paths == {
+        "/openapi.json",
+        "/docs",
+        "/docs/oauth2-redirect",
+        "/redoc",
+    }

tests/test_server_config_model.py

@@ -100,6 +100,16 @@ def test_ThingServerConfig():
         with pytest.raises(ValidationError):
             ThingServerConfig(things={name: MyThing})
 
+    # Check some good prefixes
+    for prefix in ["", "/api", "/api/v2", "/api-v2"]:
+        config = ThingServerConfig(things={}, api_prefix=prefix)
+        assert config.api_prefix == prefix
+
+    # Check some bad prefixes
+    for prefix in ["api", "/api/", "api/v2", "/badchars!"]:
+        with pytest.raises(ValidationError):
+            ThingServerConfig(things={}, api_prefix=prefix)
+
 
 def test_unimportable_modules():
     """Test that unimportable modules raise errors as expected."""

tests/test_thing_client.py

@@ -61,9 +61,9 @@ def throw_value_error(self) -> None:
 @pytest.fixture
 def thing_client():
     """Yield a test client connected to a ThingServer."""
-    server = lt.ThingServer({"test_thing": ThingToTest})
+    server = lt.ThingServer({"test_thing": ThingToTest}, api_prefix="/api/v1")
     with TestClient(server.app) as client:
-        yield lt.ThingClient.from_url("/test_thing/", client=client)
+        yield lt.ThingClient.from_url("/api/v1/test_thing/", client=client)
 
 
 def test_reading_and_setting_properties(thing_client):