fix: validate_function_params error message

[Kisbogyi]

Description

Fixes # function argument error message

When somebody created a trigger with wrong parameters the error said: "FunctionLoadError: cannot load the healthcheck function: the following parameters are declared in function.json but not in Python: {'myTimer'}" but with python function v2 functin.json is not utilized.

Examle code snippet to reproduce issue:

@bp_healthcheck.timer_trigger(
    schedule="0 */30 * * * *", arg_name="myTimer"
)
async def healthcheck() -> None:

Solution is that I rewrote the wording of the exception.

There is this comment in the call stack so I think validate_function_params should not be called when v1 function is loaded. (azure_functions_worker/dispatcher.py line 457)

# For V1, the function path will not exist and
# return None.

Moreover it has an annotations parameter, which is v2 only. So this should not be a problem.

Tests were updated!

PR information

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• [x] New Unit tests were added for the changes made and CI is passing.

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[hallvictoria]

Hi @Kisbogyi, thanks for this. I agree this error message is misleading when using the V2 programming model. This is definitely something we can get fixed.

validate_function_params is used by both the V1 & V2 programming model though, so we'll want to ensure that the error message is understandable regardless of programming model.

(For V1, the function is validated in _handle__function_load_request through the add_function call. That comment refers to indexing in _handle__functions_metadata_request, which is for V2. Also, the "annotations" parameter refers to when arguments are defined with type hints, like req: func.HttpRequest)

[Kisbogyi]

Hi! Sorry for the misunderstanding, I should have understand the code better before posting the pr. Should I open an issue for this? Sorry, for your time, and thanks!

[hallvictoria]

No worries! This is a good point to raise. Yes, please open an issue, and we'll start looking into it