Warning: this will reset all widgets on the site.

amp-wp-check-tree-shaker-savings.sh

#!/bin/bash
# Check the savings of the AMP plugin's CSS tree shaker across the core themes between two git commits.
# WARNING: This will reset your widgets!

set -e
before_head=$1
after_head=$2
if [[ -z "$before_head" ]] || [[ -z "$after_head" ]]; then
	echo "First argument needs to be the before HEAD, and second argument must be the after HEAD."
	exit 1
fi

echo "Warning: This will reset all your widgets! You have 3 seconds to cancel."
sleep 3

url=$3
if [[ -z "$url" ]]; then
	echo "Using home URL for test."
	url="$(wp option get home)/?amp"
fi

function curl_grep_included_size {
	curl -s "$url" > /tmp/response
	if grep -s 'Total excluded size' /tmp/response >/dev/null; then
		echo '-1'
	else
		cat /tmp/response | grep 'Total included size' | sed 's/.*: //' | sed 's/ bytes.*//' | sed 's/,//'
	fi
}

echo "theme | before | after | diff | savings" > results.txt;
echo "------|--------|-------|------|--------" >> results.txt;

wp transient delete --all
for theme in $(wp theme list --field=name | egrep 'twenty' | grep -v '-'); do
	wp theme activate "$theme"
	wp widget reset --all # For consistency.
	git checkout "$before_head"
	before_bytes=$(curl_grep_included_size)
	git checkout "$after_head"
	after_bytes=$(curl_grep_included_size)
	reduction_bytes=$(expr "$after_bytes" - "$before_bytes")
	reduction_percentage=$(php -r "printf( '%.2f%%', -( 1 - \$argv[1] / \$argv[2] ) * 100 );" "$after_bytes" "$before_bytes" )

	echo -e "$theme | $before_bytes | $after_bytes | $reduction_bytes | $reduction_percentage" >> results.txt
done

cat results.txt