Currently some language servers cannot parse the type of wrapped functions. _TFunc is bounded to the function.

Context

Decorated function will lose type hint in some Python language servers (e.g Pylance which VSCode will use officially in the future). Language server is working as intended, and if our wrapper does not change arg types, we should add type hint.

See: microsoft/pyright#774 (comment)

Example code:

    @allure.step("Get field '{field}' edit status.")
    def get_field_edit_status(self, field: str) -> str:
        """Get edit status of the field

        Args:
            field (str): name of the field, case insensitive

        Returns:
            str: edit status: "read only", "yes", "no".
        """
        field = field.lower()
        row_elem: WebElement = self.fields[field]
        status: str = row_elem.find_element_by_xpath(XPATH).text
        return status.lower()

VSCode with Pylance:

Argument hint:

After this PR:

Argument hint:

Checklist

• Sign Allure CLA
• Provide unit tests

No new unit test since no function change. Unit test result is the same to before this PR.