Add a test for built file size (#3075)

* Add a test for built file size

Adds a script test for building Blockly's compressed files and
checking their size to prevent unexpected increases.

* Update size for new changes

* Add full stop

.gitignore

@@ -5,6 +5,7 @@ build-debug.log
 .DS_Store
 .settings
 .project
+*.gz
 *.pyc
 *.komodoproject
 /nbproject/private/

tests/run_all_tests.sh

@@ -67,6 +67,9 @@ run_test_command "generators" "tests/scripts/run_generators.sh"
 # Generate TypeScript typings and ensure there are no errors.
 run_test_command "typings" "tests/scripts/compile_typings.sh"
 
+# Check the sizes of built files for unexpected growth.
+run_test_command "metadata" "tests/scripts/check_metadata.sh"
+
 # # Attempt advanced compilation of a Blockly app.
 # run_test_command "compile" "tests/compile/compile.sh"
 

tests/scripts/check_metadata.sh

@@ -0,0 +1,57 @@
+#!/bin/bash
+
+# Checks the size of generated files and verifies they aren't growing
+# unreasonably.
+
+# These values should be updated with each release
+# Size of blockly_compressed.js
+blockly_size_expected=573000 # 813K in July 2019 release
+# Size of blocks_compressed.js
+blocks_size_expected=76500 # 75K in July 2019 release
+# Size of blockly_compressed.js.gz
+blockly_gz_size_expected=123000 # 180K in July 2019 release
+# Size of blocks_compressed.js.gz
+blocks_gz_size_expected=15200 # 14.5K in July 2019 release
+
+# ANSI colors
+BOLD_GREEN='\033[1;32m'
+BOLD_RED='\033[1;31m'
+ANSI_RESET='\033[0m'
+
+# Build the compressed files for core and blocks
+echo "Building files"
+npm install
+gulp build-core
+gulp build-blocks
+
+# GZip them for additional size comparisons
+echo "Zipping the compressed files"
+gzip -c blockly_compressed.js > blockly_compressed.js.gz
+gzip -c blocks_compressed.js > blocks_compressed.js.gz
+
+# Check the sizes of the files
+
+has_failed=0
+
+compare_size() {
+	local name=$1
+	local expected=$2
+	local compare=$(echo "$expected * 1.1 / 1" | bc)
+
+	local size=$(wc -c <"$name")
+
+	if (( $size > $compare))
+	then
+		echo -e "${BOLD_RED}Failed: Size of $name has grown more than 10%. $size vs $expected ${ANSI_RESET}" >&2
+  		has_failed=1
+  	else
+  		echo -e "${BOLD_GREEN}Size of $name at $size compared to previous $expected.${ANSI_RESET}"
+  	fi
+}
+
+compare_size "blockly_compressed.js" $blockly_size_expected
+compare_size "blocks_compressed.js" $blocks_size_expected
+compare_size "blockly_compressed.js.gz" $blockly_gz_size_expected
+compare_size "blocks_compressed.js.gz" $blocks_gz_size_expected
+
+exit $has_failed