Update fallback tests for new fallback templating.

Author: julianstirling

src/labthings_fastapi/server/fallback.py

@@ -31,18 +31,18 @@
 class FallbackContext:
     """A dataclass to provide the context of the server failing to load."""
 
-    error: BaseException | None
+    error: BaseException | None = None
     """The error caught when running uvicorn.run."""
 
-    server: ThingServer | None
+    server: ThingServer | None = None
     """The ThingServer that failed to start."""
 
-    config: ThingServerConfig | dict[str, Any] | None
+    config: ThingServerConfig | dict[str, Any] | None = None
     """The config used to set up the server.
 
     This can be the ThingServerConfig, or the dict read from the JSON file."""
 
-    log_history: str | None
+    log_history: str | None = None
     """Any logging history to show."""
 
 

tests/test_fallback.py

@@ -6,13 +6,14 @@
 """
 
 import re
+from html import unescape
 
 import pytest
 import uvicorn
 
 from fastapi.testclient import TestClient
 import labthings_fastapi as lt
-from labthings_fastapi.server.fallback import app
+from labthings_fastapi.server.fallback import app, FallbackContext
 from labthings_fastapi.example_things import ThingThatCantStart
 
 CONFIG_DICT = {
@@ -29,21 +30,20 @@
 @pytest.fixture(autouse=True)
 def reset_app_state():
     """Reset the fallback app state before each fallback test."""
-    app.labthings_config = None
-    app.labthings_server = None
-    app.labthings_error = None
-    app.log_history = None
+    app._context = None
 
 
 def test_fallback_redirect():
     """Test that the redirect works."""
+    # Need to set a context even if everything in it is empty.
+    app.set_context(FallbackContext())
     with TestClient(app) as client:
         response = client.get("/")
         # No history as no redirect
         assert len(response.history) == 0
         html = response.text
-        # test that something when wrong is shown
-        assert "Something went wrong" in html
+        # Check that the basic failure message is shown
+        assert "The LabThings server failed during startup." in html
 
         # Now try another url
         response = client.get("/foo/bar")
@@ -53,77 +53,80 @@ def test_fallback_redirect():
 
         # Redirects to error page.
         html = response.text
-        # test that something when wrong is shown
-        assert "Something went wrong" in html
+        # Check that the basic failure message is shown
+        assert "The LabThings server failed during startup." in html
 
 
 def test_fallback_empty():
+    # Need to set a context even if everything in it is empty.
+    app.set_context(FallbackContext())
     with TestClient(app) as client:
         response = client.get("/")
         html = response.text
-        # test that something when wrong is shown
-        assert "Something went wrong" in html
-        assert "No logging info available" in html
+        # Check that the basic failure message is shown
+        assert "The LabThings server failed during startup." in html
+        assert "No logging information available." in html
 
 
 def test_fallback_with_config_dict():
     """Check that fallback server prints a config dictionary as JSON."""
-    app.labthings_config = CONFIG_DICT
+    app.set_context(FallbackContext(config=CONFIG_DICT))
     with TestClient(app) as client:
         response = client.get("/")
         html = response.text
-        assert "Something went wrong" in html
-        assert "No logging info available" in html
-        assert '"thing1": "labthings_fastapi.example_things:MyThing"' in html
-        assert '"class": "labthings_fastapi.example_things:MyThing"' in html
+        assert "The LabThings server failed during startup." in html
+        assert "No logging information available." in html
+        assert '"thing1": "labthings_fastapi.example_things:MyThing"' in unescape(html)
+        assert '"class": "labthings_fastapi.example_things:MyThing"' in unescape(html)
 
 
 def test_fallback_with_config_obj():
     """Check that fallback server prints the config object as JSON."""
     config = lt.ThingServerConfig.model_validate(CONFIG_DICT)
-    app.labthings_config = config
+    app.set_context(FallbackContext(config=config))
     with TestClient(app) as client:
         response = client.get("/")
         html = response.text
-        assert "Something went wrong" in html
-        assert "No logging info available" in html
+        assert "The LabThings server failed during startup." in html
+        assert "No logging information available." in html
         assert "thing1" in html
         assert "thing2" in html
         cls_regex = re.compile(r'"cls": "labthings_fastapi\.example_things\.MyThing"')
-        assert len(cls_regex.findall(html)) == 2
+        assert len(cls_regex.findall(unescape(html))) == 2
 
 
 def test_fallback_with_error():
-    app.labthings_error = RuntimeError("Custom error message")
+    app.set_context(FallbackContext(error=RuntimeError("Custom error message")))
     with TestClient(app) as client:
         response = client.get("/")
         html = response.text
-        assert "Something went wrong" in html
-        assert "No logging info available" in html
+        assert "The LabThings server failed during startup." in html
+        assert "No logging information available." in html
         assert "RuntimeError" in html
         assert "Custom error message" in html
 
 
 def test_fallback_with_server():
     config = lt.ThingServerConfig.model_validate(CONFIG_DICT)
-    app.labthings_server = lt.ThingServer.from_config(config)
+    server = lt.ThingServer.from_config(config)
+    app.set_context(FallbackContext(server=server))
     with TestClient(app) as client:
         response = client.get("/")
         html = response.text
-        assert "Something went wrong" in html
-        assert "No logging info available" in html
+        assert "The LabThings server failed during startup." in html
+        assert "No logging information available." in html
         assert "thing1" in html
         assert "thing2" in html
 
 
 def test_fallback_with_log():
-    app.log_history = "Fake log content"
+    app.set_context(FallbackContext(log_history="Fake log content"))
     with TestClient(app) as client:
         response = client.get("/")
         html = response.text
-        assert "Something went wrong" in html
-        assert "No logging info available" not in html
-        assert "<p>Logging info</p>" in html
+        assert "The LabThings server failed during startup." in html
+        assert "No logging information available." not in html
+        assert "<h2>Logging</h2>" in html
         assert "Fake log content" in html
 
 
@@ -146,17 +149,16 @@ def test_actual_server_fallback():
     thing_error = server.startup_failure["exception"]
     assert isinstance(thing_error, RuntimeError)
 
-    app.labthings_server = server
-    app.labthings_error = server_error
+    app.set_context(FallbackContext(server=server, error=server_error))
     with TestClient(app) as client:
         response = client.get("/")
         html = response.text
-        assert "Something went wrong" in html
+        assert "The LabThings server failed during startup." in html
         # Shouldn't be displaying the meaningless SystemExit
         assert "SystemExit" not in html
 
         # The message from when the Thing errored should be displayed
-        assert str(thing_error) in html
+        assert str(thing_error) in unescape(html)
         # With the traceback
-        assert 'labthings_fastapi/example_things/__init__.py", line' in html
-        assert f'RuntimeError("{thing_error}")' in html
+        assert 'labthings_fastapi/example_things/__init__.py", line' in unescape(html)
+        assert f'RuntimeError("{thing_error}")' in unescape(html)