argonaut.nvim/lua/argonaut/config.lua

local configs = {
    default = {
        line_prefix = '',
        padded_braces = {},
        tail_comma = false,
        tail_comma_braces = {},
        tail_indent_braces = {},
        wrap_closing_brace = true,
        comma_first = false,
        comma_first_indent = false,
    },
    go = {
        tail_comma = true,
    }
}

local function set(opts, filetypes)
    if opts then
        if type(filetypes) == 'string' then
            filetypes = {filetypes}
        elseif not filetypes then
            filetypes = {'default'}
        end

        for _, filetype in ipairs(filetypes) do
            local config = configs[filetype]
            if not config then
                config = {}
                configs[filetype] = config
            end

            for key, value in pairs(opts) do
                config[key] = value
            end
        end
    end
end

local function get()
    local file_config = configs[vim.bo.filetype]

    local config = {}
    for key, value in pairs(configs.default) do
        config[key] = value
        if file_config then
            local file_value = file_config[key]
            if file_value ~= nil then
                config[key] = file_config[key]
            end
        end
    end

    return config
end

return {
    set = set,
    get = get,
}