besu/.github/workflows/splitTestsByTime.sh

#!/bin/bash

REPORTS_DIR="$1"
SPLIT_COUNT=$2
SPLIT_INDEX=$3

# extract tests time from Junit XML reports
find "$REPORTS_DIR" -type f -name TEST-*.xml | xargs -I{} bash -c "xmlstarlet sel -t -v 'sum(//testcase/@time)' '{}'; echo '{}' | sed 's/.*TEST\-\(.*\)\.xml/ \1/'" > tmp/timing.tsv

# Sort times in descending order
IFS=$'\n' sorted=($(sort -nr tmp/timing.tsv))
unset IFS

sums=()
tests=()

# Initialize sums
for ((i=0; i<SPLIT_COUNT; i++))
do
	sums[$i]=0
done

# add tests to groups trying to balance the sum of execution time of each group
for line in "${sorted[@]}"; do
	line_parts=( $line )
	test_time=${line_parts[0]//./} # convert to millis
	test_time=${test_time##0} # remove leading zeros
	test_name=${line_parts[1]}
	
	# Find index of min sum
	idx_min_sum=0
	min_sum=${sums[0]}
	for ((i=0; i<SPLIT_COUNT; i++))
	do		
		if [[ ${sums[$i]} -lt $min_sum ]]
		then
			idx_min_sum=$i		
			min_sum=${sums[$i]}
		fi
	done

	# Add the test to the min sum list
	min_sum_tests=${tests[$idx_min_sum]}
	tests[$idx_min_sum]="${min_sum_tests}${test_name},"
	
	# Update the sums
	((sums[idx_min_sum]+=test_time))

done

# return the requests index, without quotes to drop the last trailing space
echo ${tests[$SPLIT_INDEX]//,/ }