bug in core document.get

[casesolved-co-uk]

There appears to be a huge bug in the document core get() function.

Practically everywhere in the code (frappe and ERPNext) the assumption is made that doc.get() has the same definition as dict.get(). This is not true.

document.get(key, filters=None, limit=None, default=None)

dict.get(key[, default])

This fails for examples like:

doc.get("att1", 0.0)                   # returns None
doc.get("att2", {})                    # returns None
doc.get("att3", {"default": "hello"}   # returns an error if att3 is not a list (child table)

See the following PR that illustrates the issue with the Warnings printed in the test output:

#26279

https://github.com/frappe/frappe/blob/069612366197e4ed98d090d99cc068c8525d09ca/frappe/model/base_document.py#L215C2-L215C61