Mapping from file in jq

I'm trying to use jq to look up data from a json file with account mappings. So given an account number as input, I want to look up it's name from a file, and it needs to handle the account not being found.

echo '["1100", "1350"]' | jq --slurpfile accountsdata accounts.json '    def get_account_data(account):        [$accountsdata[]        | .[]        | select((.accountnumber | tostring) == (account | tostring))] as $output        | if $output | length == 0 then {"name": ("no mapping for " + account +".")} else $output[0] end;    def get_name(account):        get_account_data(account).name;. | map(get_name(.))'

The account mapping file is as follows:

[  {"accountnumber": 1100,"name": "Account A"  },  {"accountnumber": 1350,"name": "Account B"  },  {"accountnumber": 1356,"name": "Account C"  }]

Expected output:

["Account A","Account B"]

Actual output:

["no mapping for 1100.","no mapping for 1350."]

However, if I change the call from . | map(get_name(.)) to . | map(get_name("1100")) (i.e. hardcode the accountnumber), I get the expected

["Account A","Account A"]

What am I missing?