Injects some arbitrary javascript into Slack for theme installation reasons

slack-theme.sh

#!/usr/bin/env bash

if ! uname | grep -iq darwin; then
    echo "This script is designed for Mac OSX use" >&2
    exit 1
fi

if ! [ -e "patch.js" ]; then
    echo "Place your javascript to inject in patch.js"  >&2
    exit 1
fi

cleanup() {
    rm *.manifest 2>/dev/null
    rm *.list 2>/dev/null
    rm -rf app.asar* 2>/dev/null
    rm -rf app_extracted* 2>/dev/null
    rm ssb-interop.bundle.js 2>/dev/null
}

cleanup

if [ -a "Slack.app" ]; then
    echo "Slack.app already exists... skipping backup"
else
    echo "Backing up Slack.app"
    cp -a /Applications/Slack.app Slack.app
fi

# Grab app.asar
cp Slack.app/Contents/Resources/app.asar .
cp -R /Applications/Slack.app/Contents/Resources/app.asar.unpacked/ app.asar.unpacked
find app.asar.unpacked -type f | sed 's/^app\.asar\.unpacked//' > unpacked.manifest

# extract
asar extract app.asar app_extracted
find app_extracted -type f | sed 's/^app_extracted//' > all.manifest
cat all.manifest unpacked.manifest | sort | uniq -u > only-packed.manifest

# do scketchy things

echo -ne "\n\n" >> app_extracted/dist/ssb-interop.bundle.js
cat patch.js >> app_extracted/dist/ssb-interop.bundle.js

# pack
asar pack --unpack "{*.node,*.woff2,*.svg,*.less,*.ico,emoji_2017_12_06_sheet_apple_64_indexed_256.webp,emoji_2017_12_06_sheet_google_64_indexed_256.webp,logo_spinner.gif,no_connection.webp}" --unpack-dir "{dist/static/extensions/react-devtools,dist/static/fonts}" app_extracted app.asar.2
find app.asar.2.unpacked -type f | sed 's/^app\.asar\.2\.unpacked//' > unpacked.2.manifest

# sanity checks
asar list app.asar > app.asar.list
asar list app.asar.2 > app.asar.2.list

diff app.asar app.asar.2

if [ "$(diff -y --suppress-common-lines unpacked.manifest unpacked.2.manifest | grep '^' | wc -l | sed 's/^ *//')" != "0" ]; then
    echo "Excluded files differ" >&2
    exit 1
fi

if [ "$(diff -y --suppress-common-lines app.asar.list app.asar.2.list | grep '^' | wc -l | sed 's/^ *//')" != "0" ]; then
    echo "Packed files differ" >&2
    exit 1
fi

# Install
echo "root privilege is required to install the patch"
sudo mv app.asar.2 /Applications/Slack.app/Contents/Resources/app.asar
sudo chown root:wheel /Applications/Slack.app/Contents/Resources/app.asar
sudo chmod 644 /Applications/Slack.app/Contents/Resources/app.asar

cleanup

echo "A copy of the patched ssb-interop.bundle.js has been placed in this folder so you can validate"
asar extract-file /Applications/Slack.app/Contents/Resources/app.asar dist/ssb-interop.bundle.js