dhondt | Simple Node.js module | Runtime Evironment library

I'm trying to calculate the number of seats parties should have in municipal councils using a function from the electoral package, and have a long-format dataframe that is sorted according to municipalities.

However, I seem unable to get the function to work within the groups, and instead get the following error:

Error in seats_ha(parties = mandates$party, votes = mandates$votes, n_seats = 25, : every party name must be unique

I have tried using both do() and group_map(), as this is what was suggested in this thread: Run a custom function on a data frame in R, by group, and summarise would not work since the function is expected to return several rows of values, not one summary value.

I have also tried using the dHondt()-function from the coalitions package, but to no avail, just a different error:

When using do:

Error: Results 1, 2 must be data frames, not integer

When using group_map:

Error: Can't convert an integer vector to function

Does anyone have an idea on how to solve this? :)

Some sample code: