Error messages not clear enough

[Henning Wöhrmann]

Describe the problem

When using the flag --data-file to input answers, there may be a validation error. Since normally, the error would be raised directly after answering, it is clear which questions was at fault. But with the data file, the error raised does not contain the question name or the choice in case of using choices. Therefore it is hard to find the wrong value in the data-file.

Template

preset:
  type: str
  help: Which config preset do you want to use?
  choices:
    - IIoT
    - GPU
  default: IIoT

config_mode:
  type: str
  help: Which config mode do you want to use?
  choices:
    Basic: basic
    Advanced: advanced
  default: basic

box_environment:
  when: "{{config_mode == 'advanced'}}"
  type: str
  help: In which environment will the box run?
  choices:
    Production: prod
    Development: dev
  default: prod
  validator: "{% if config_mode != 'advanced' %}Requires advanced config mode{% endif %}"

To Reproduce

When using the following values.yaml:

preset: IIoT
config_mode: basic
box_environment: dev

and the command copier copy <src> <dst> --data-file values.yaml you would get the following error:

Traceback (most recent call last):
  File "/home/henning/.local/bin/copier", line 8, in <module>
    sys.exit(copier_app_run())
  File "/home/henning/.local/pipx/venvs/copier-dist/lib/python3.10/site-packages/plumbum/cli/application.py", line 638, in run
    inst, retcode = subapp.run(argv, exit=False)
  File "/home/henning/.local/pipx/venvs/copier-dist/lib/python3.10/site-packages/plumbum/cli/application.py", line 633, in run
    retcode = inst.main(*tailargs)
  File "/home/henning/.local/pipx/venvs/copier-dist/lib/python3.10/site-packages/decorator.py", line 232, in fun
    return caller(func, *(extras + args), **kw)
  File "/home/henning/.local/pipx/venvs/copier-dist/lib/python3.10/site-packages/copier/cli.py", line 72, in handle_exceptions
    return method(*args, **kwargs)
  File "/home/henning/.local/pipx/venvs/copier-dist/lib/python3.10/site-packages/copier/cli.py", line 265, in main
    with self._worker(
  File "/home/henning/.local/pipx/venvs/copier-dist/lib/python3.10/site-packages/copier/main.py", line 205, in __exit__
    raise value
  File "/home/henning/.local/pipx/venvs/copier-dist/lib/python3.10/site-packages/copier/cli.py", line 272, in main
    worker.run_copy()
  File "/home/henning/.local/pipx/venvs/copier-dist/lib/python3.10/site-packages/copier/main.py", line 744, in run_copy
    self._ask()
  File "/home/henning/.local/pipx/venvs/copier-dist/lib/python3.10/site-packages/copier/main.py", line 443, in _ask
    question.validate_answer(answer)
  File "/home/henning/.local/pipx/venvs/copier-dist/lib/python3.10/site-packages/copier/user_data.py", line 411, in validate_answer
    raise ValidationError(message=err_msg)
prompt_toolkit.validation.ValidationError: Requires advanced config mode

With this message, it isn't clear which question was answered wrong

Logs

No response

Expected behavior

Include nessessory names: question, choice or whatever is the most helpful.

What would be really nice, to validate similar to pydantic, where all validation errors are listed, but that would probably be too much, since it would only be useful when using --data-file

Screenshots/screencasts/logs

No response

Operating system

Linux

Operating system distribution and version

22.04

Copier version

9.1.0

Python version

3.10

Installation method

pipx+git

Additional context

No response

[Salem Olorundare]

Hi, is there any update on this issue?

[Timothée Mazzucotelli]

Hi @itz-salemm, as you can see, no, there is no update. Would you like to work on it 🙂?

[Salem Olorundare]

Yes, I would get to work on it. I just wanted to confirm.

Thank you.