Passing "script_name" as empty string causes API request to fail

What is happening?

Passing request body to /agent-scheduler/v1/queue/txt2img with empty string in "script_name" parameters causes the API request to fail with error Exception: Not found script

What should happen?

The endpoint handler should recognise empty string in "script_name" as a valid value (as if intention is to not use any script) and continue as normal rather than throwing exception. Note that the intended behaviour is displayed when sending "script_name" as empty string to /sdapi/v1/txt2img.

Full request body:

{
  "prompt": "__prompt__",
  "negative_prompt": "__negative__",
  "styles": [],
  "seed": -1,
  "subseed": -1,
  "subseed_strength": 0,
  "seed_resize_from_h": -1,
  "seed_resize_from_w": -1,
  "sampler_name": "DPM++ 2M Karras",
  "batch_size": 2,
  "n_iter": 1,
  "steps": 50,
  "cfg_scale": 7,
  "width": 512,
  "height": 512,
  "restore_faces": true,
  "tiling": true,
  "do_not_save_samples": false,
  "do_not_save_grid": false,
  "eta": 0,
  "denoising_strength": 0.3,
  "s_min_uncond": 0,
  "s_churn": 0,
  "s_tmax": 0,
  "s_tmin": 0,
  "s_noise": 0,
  "override_settings": {},
  "override_settings_restore_afterwards": true,
  "refiner_checkpoint": "",
  "refiner_switch_at": 0,
  "disable_extra_networks": false,
  "comments": {},
  "enable_hr": true,
  "firstphase_width": 0,
  "firstphase_height": 0,
  "hr_scale": 2,
  "hr_upscaler": "4x-UltraSharp",
  "hr_second_pass_steps": 15,
  "hr_resize_x": 0,
  "hr_resize_y": 0,
  "hr_checkpoint_name": "",
  "hr_sampler_name": "",
  "hr_prompt": "",
  "hr_negative_prompt": "",
  "sampler_index": "",
  "script_name": "",
  "script_args": [],
  "send_images": true,
  "save_images": false,
  "alwayson_scripts": {},
  "checkpoint": "DigitalArt\\feverdream_v10.safetensors [830772ed8e]",
  "vae": "",
  "callback_url": ""  
}

Full error:

...
Traceback (most recent call last):
      File "C:\AI\stable-diffusion-webui\modules\api\api.py", line 187, in exception_handling
        return await call_next(request)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\middleware\base.py", line 84, in call_next
        raise app_exc
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\middleware\base.py", line 70, in coro
        await self.app(scope, receive_or_disconnect, send_no_error)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\middleware\base.py", line 108, in __call__
        response = await self.dispatch_func(request, call_next)
      File "C:\AI\stable-diffusion-webui\modules\api\api.py", line 151, in log_and_time
        res: Response = await call_next(req)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\middleware\base.py", line 84, in call_next
        raise app_exc
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\middleware\base.py", line 70, in coro
        await self.app(scope, receive_or_disconnect, send_no_error)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\middleware\cors.py", line 92, in __call__
        await self.simple_response(scope, receive, send, request_headers=headers)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\middleware\cors.py", line 147, in simple_response
        await self.app(scope, receive, send)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\middleware\gzip.py", line 24, in __call__
        await responder(scope, receive, send)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\middleware\gzip.py", line 44, in __call__
        await self.app(scope, receive, self.send_with_gzip)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\middleware\exceptions.py", line 79, in __call__
        raise exc
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\middleware\exceptions.py", line 68, in __call__
        await self.app(scope, receive, sender)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\fastapi\middleware\asyncexitstack.py", line 21, in __call__
        raise e
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\fastapi\middleware\asyncexitstack.py", line 18, in __call__
        await self.app(scope, receive, send)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\routing.py", line 718, in __call__
        await route.handle(scope, receive, send)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\routing.py", line 276, in handle
        await self.app(scope, receive, send)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\routing.py", line 66, in app
        response = await func(request)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\fastapi\routing.py", line 237, in app
        raw_response = await run_endpoint_function(
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\fastapi\routing.py", line 165, in run_endpoint_function
        return await run_in_threadpool(dependant.call, **values)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\starlette\concurrency.py", line 41, in run_in_threadpool
        return await anyio.to_thread.run_sync(func, *args)
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\anyio\to_thread.py", line 33, in run_sync
        return await get_asynclib().run_sync_in_worker_thread(
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\anyio\_backends\_asyncio.py", line 877, in run_sync_in_worker_thread
        return await future
      File "C:\AI\stable-diffusion-webui\venv\lib\site-packages\anyio\_backends\_asyncio.py", line 807, in run
        result = context.run(func, *args)
      File "C:\AI\stable-diffusion-webui\extensions\sd-webui-agent-scheduler\agent_scheduler\api.py", line 116, in queue_txt2img
        task = task_runner.register_api_task(
      File "C:\AI\stable-diffusion-webui\extensions\sd-webui-agent-scheduler\agent_scheduler\task_runner.py", line 304, in register_api_task
        (params, script_params) = self.__serialize_api_task_args(is_img2img, checkpoint=checkpoint, vae=vae, **args)
      File "C:\AI\stable-diffusion-webui\extensions\sd-webui-agent-scheduler\agent_scheduler\task_runner.py", line 138, in __serialize_api_task_args
        named_args = serialize_api_task_args(api_args, is_img2img, checkpoint=checkpoint, vae=vae)
      File "C:\AI\stable-diffusion-webui\extensions\sd-webui-agent-scheduler\agent_scheduler\task_helpers.py", line 486, in serialize_api_task_args
        raise Exception(f"Not found script {script_name}")
    Exception: Not found script

Side note and possible solution

After poking around your source code I've found the bug in function serialize_api_task_args where you check whether script_name is not None if script_name is not None: Somewhere there you should allow for check that the script_name is not an empty script too.

Workaround

Since the code is checking for None, passing a null in the "script_name" does bypass that faulty check.

ArtVentureX / sd-webui-agent-scheduler