Neovim Benchmark Script

bench-nvim.sh

#!/usr/bin/env bash

RUNS=${1:-10}
LOGFILE=$(mktemp)
TOTAL_TIME=0

RED_BOLD='\033[1;31m' # Bold and Red
RED='\033[0;31m'      # Standard Red
NC='\033[0m'          # No Color (reset)

for i in 1; do
	# \r returns the cursor to the start of the line so it overwrites instead of stacking
	printf "\rBenchmarking Neovim startup time over %d runs..." "$RUNS" "$i"
	sleep 1
done
printf "\rBenchmarking Neovim startup time over %d runs... Go!          \n" "$RUNS"
echo "------------------------------------------------"

for ((i = 1; i <= RUNS; i++)); do
	nvim --headless --startuptime "$LOGFILE" -c "qa"

	# Extract the first column (timestamp) from the "NVIM STARTED" line
	RUN_TIME=$(awk '/NVIM STARTED/ {print $1}' "$LOGFILE" | tail -n 1)

	if [[ -z "$RUN_TIME" ]]; then
		echo "Error: Could not parse startup time from log."
		rm -f "$LOGFILE"
		exit 1
	fi

	printf "${RED_BOLD}Run %02d:${NC} %7s ms\n\n" "$i" "$RUN_TIME"

	TOTAL_TIME=$(awk "BEGIN {print $TOTAL_TIME + $RUN_TIME}")
done

AVG_TIME=$(awk "BEGIN {printf \"%.2f\", $TOTAL_TIME / $RUNS}")

echo "------------------------------------------------"
printf "Average startup time: ${RED}%s ms${NC}\n" "${AVG_TIME}"

rm -f "$LOGFILE"