More idiomatic errors for FastAPI

libs/studio/kiln_studio/custom_errors.py

@@ -1,4 +1,4 @@
-from fastapi import FastAPI, Request, status
+from fastapi import FastAPI, HTTPException, Request, status
 from fastapi.exceptions import RequestValidationError
 from fastapi.responses import JSONResponse
 from pydantic import ValidationError
@@ -49,3 +49,11 @@ async def validation_exception_handler(
                 "source_errors": exc.errors(),
             },
         )
+
+    # Wrap in a format that the client can understand (message, and error_messages)
+    @app.exception_handler(HTTPException)
+    async def http_exception_handler(request: Request, exc: HTTPException):
+        return JSONResponse(
+            status_code=exc.status_code,
+            content={"message": exc.detail},
+        )

libs/studio/kiln_studio/project_management.py

@@ -1,8 +1,7 @@
 import os
 from pathlib import Path
 
-from fastapi import FastAPI
-from fastapi.responses import JSONResponse
+from fastapi import FastAPI, HTTPException
 
 from libs.core.kiln_ai.datamodel import Project
 from libs.core.kiln_ai.utils.config import Config
@@ -17,11 +16,9 @@ def connect_project_management(app: FastAPI):
     async def create_project(project: Project):
         project_path = os.path.join(default_project_path(), project.name)
         if os.path.exists(project_path):
-            return JSONResponse(
+            raise HTTPException(
                 status_code=400,
-                content={
-                    "message": "Project with this name already exists. Please choose a different name."
-                },
+                detail="Project with this name already exists. Please choose a different name.",
             )
 
         os.makedirs(project_path)

libs/studio/kiln_studio/task_management.py

@@ -2,10 +2,7 @@
 from pathlib import Path
 from typing import Any, Dict
 
-from fastapi import FastAPI
-from fastapi.exceptions import RequestValidationError
-from fastapi.responses import JSONResponse
-from pydantic import ValidationError
+from fastapi import FastAPI, HTTPException
 
 from libs.core.kiln_ai.datamodel import Project, Task
 
@@ -14,32 +11,26 @@ def connect_task_management(app: FastAPI):
     @app.post("/api/task")
     async def create_task(task_data: Dict[str, Any], project_path: str | None = None):
         if project_path is None or not os.path.exists(project_path):
-            return JSONResponse(
+            raise HTTPException(
                 status_code=400,
-                content={
-                    "message": "Parent project not found. Can't create task.",
-                },
+                detail="Parent project not found. Can't create task.",
             )
 
         try:
             parent_project = Project.load_from_file(Path(project_path))
         except Exception as e:
-            return JSONResponse(
+            raise HTTPException(
                 status_code=500,
-                content={
-                    "message": f"Failed to load parent project: {e}",
-                },
+                detail=f"Failed to load parent project: {e}",
             )
 
         task = Task.validate_and_save_with_subrelations(
             task_data, parent=parent_project
         )
         if task is None:
-            return JSONResponse(
+            raise HTTPException(
                 status_code=400,
-                content={
-                    "message": "Failed to create task.",
-                },
+                detail="Failed to create task.",
             )
 
         returnTask = task.model_dump()

libs/studio/kiln_studio/test_project_management.py

@@ -8,6 +8,7 @@
 
 from libs.core.kiln_ai.datamodel import Project
 from libs.core.kiln_ai.utils.config import Config
+from libs.studio.kiln_studio.custom_errors import connect_custom_errors
 from libs.studio.kiln_studio.project_management import (
     connect_project_management,
     default_project_path,
@@ -18,6 +19,7 @@
 def app():
     app = FastAPI()
     connect_project_management(app)
+    connect_custom_errors(app)
     return app
 
 

libs/studio/kiln_studio/test_task_management.py

@@ -7,13 +7,15 @@
 from fastapi.testclient import TestClient
 
 from libs.core.kiln_ai.datamodel import Project, Task
+from libs.studio.kiln_studio.custom_errors import connect_custom_errors
 from libs.studio.kiln_studio.task_management import connect_task_management
 
 
 @pytest.fixture
 def app():
     app = FastAPI()
     connect_task_management(app)
+    connect_custom_errors(app)
     return app