Implement fields.Method handler for marshmallow

[psaiz]

Package version (if known):1.5.0

Describe the bug

The convertion from marshmallow schema to json_schema fails for fields that are declared as method. For instance, for the user management, the conversion of the is_current_user fails.

Steps to Reproduce

With version 1.5.0:

Traceback (most recent call last):
  File "/Users/psaiz/github/invenio-administration/invenio_administration/marshmallow_utils.py", line 104, in jsonify_schema
    "type": custom_mapping[field_type_name],
KeyError: <class 'marshmallow.fields.Method'>

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/psaiz/.local/share/virtualenvs/psaiz-master-PcfYpoPq/lib/python3.9/site-packages/flask/app.py", line 2552, in __call__
    return self.wsgi_app(environ, start_response)
  File "/Users/psaiz/.local/share/virtualenvs/psaiz-master-PcfYpoPq/lib/python3.9/site-packages/werkzeug/middleware/proxy_fix.py", line 187, in __call__
    return self.app(environ, start_response)
  File "/Users/psaiz/.local/share/virtualenvs/psaiz-master-PcfYpoPq/lib/python3.9/site-packages/werkzeug/middleware/dispatcher.py", line 78, in __call__
    return app(environ, start_response)
  File "/Users/psaiz/.local/share/virtualenvs/psaiz-master-PcfYpoPq/lib/python3.9/site-packages/flask/app.py", line 2532, in wsgi_app
    response = self.handle_exception(e)
  File "/Users/psaiz/.local/share/virtualenvs/psaiz-master-PcfYpoPq/lib/python3.9/site-packages/flask/app.py", line 2529, in wsgi_app
    response = self.full_dispatch_request()
  File "/Users/psaiz/.local/share/virtualenvs/psaiz-master-PcfYpoPq/lib/python3.9/site-packages/flask/app.py", line 1825, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Users/psaiz/.local/share/virtualenvs/psaiz-master-PcfYpoPq/lib/python3.9/site-packages/flask/app.py", line 1823, in full_dispatch_request
    rv = self.dispatch_request()
  File "/Users/psaiz/.local/share/virtualenvs/psaiz-master-PcfYpoPq/lib/python3.9/site-packages/flask/app.py", line 1799, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
  File "/Users/psaiz/.local/share/virtualenvs/psaiz-master-PcfYpoPq/lib/python3.9/site-packages/flask_principal.py", line 199, in _decorated
    rv = f(*args, **kw)
  File "/Users/psaiz/.local/share/virtualenvs/psaiz-master-PcfYpoPq/lib/python3.9/site-packages/flask/views.py", line 107, in view
    return current_app.ensure_sync(self.dispatch_request)(**kwargs)
  File "/Users/psaiz/.local/share/virtualenvs/psaiz-master-PcfYpoPq/lib/python3.9/site-packages/flask/views.py", line 188, in dispatch_request
    return current_app.ensure_sync(meth)(**kwargs)
  File "/Users/psaiz/github/invenio-administration/invenio_administration/views/base.py", line 388, in get
    serialized_schema = self._schema_to_json(schema)
  File "/Users/psaiz/github/invenio-administration/invenio_administration/views/base.py", line 195, in _schema_to_json
    return jsonify_schema(schema)
  File "/Users/psaiz/github/invenio-administration/invenio_administration/marshmallow_utils.py", line 109, in jsonify_schema
    raise Exception(f"Unrecognised schema field {field}: {field_type_name}")
Exception: Unrecognised schema field is_current_user: <class 'marshmallow.fields.Method'>

As a workaround, the following code was added:

+++ b/invenio_administration/marshmallow_utils.py
@@ -36,6 +36,7 @@ custom_mapping = {
     fields.Date: "date",
     fields.TimeDelta: "timedelta",
     fields.Decimal: "decimal",
+    fields.Method: None,

This might need some better implementation

Expected behavior

Screenshots (if applicable)

Additional context