Update column in file based on associative array value in bash - bash

Question

So I have a file named testingFruits.csv with the following columns:
name,value_id,size
apple,1,small
mango,2,small
banana,3,medium
watermelon,4,large
I also have an associative array that stores the following data:
fruitSizes[apple] = xsmall
fruitSizes[mango] = small
fruitSizes[banana] = medium
fruitSizes[watermelon] = xlarge
Is there anyway I can update the 'size' column within the file based on the data within the associative array for each value in the 'name' column?
I've tried using awk but I had no luck. Here's a sample of what I tried to do:
awk -v t="${fruitSizes[*]}" 'BEGIN{n=split(t,arrayval,""); ($1 in arrayval) {$3=arrayval[$1]}' "testingFruits.csv"
I understand this command would get the bash defined array fruitSizes, do a split on all the values, then check if the first column (name) is within the fruitSizes array. If it is, then it would update the third column (size) with the value found in fruitSizes for that specific name.
Unfortunately this gives me the following error:
Argument list too long
This is the expected output I'd like in the same testingFruits.csv file:
name,value_id,size
apple,1,xsmall
mango,2,small
banana,3,medium
watermelon,4,xlarge
One edge case I'd like to handle is the presence of duplicate values in the name column with different values for the value_id and size columns.

Answer 1

If you want to stick to an awk script, pass the array via stdin to avoid running into ARG_MAX issues.
Since your array is associative, listing only the values ${fruitSizes[#]} is not sufficient. You also need the keys ${!fruitSizes[#]}. pr -2 can pair the keys and values in one line.
This assumes that ${fruitSizes[#]} and ${!fruitSizes[#]} expand in the same order, and your keys and values are free of the field separator (, in this case).
printf %s\\n "${!fruitSizes[#]}" "${fruitSizes[#]}" | pr -t -2 -s, |
awk -F, -v OFS=, 'NR==FNR {a[$1]=$2; next} $1 in a {$3=a[$1]} 1' - testingFruits.csv
However, I'm wondering where the array fruitSizes comes from. If you read it from a file or something like that, it would be easier to leave out the array altogether and do everything in awk.