launch_dev_browser.sh

#!/bin/bash

declare -r entropy=$(xxd -l16 -ps /dev/urandom)

#declare -r CHROME_DIR="${HOME}/.chromeDevTemp"
declare -r chrome_dir="/tmp/chrome/${entropy}"

# See flags available and documentation:
# https://chromium.googlesource.com/chromium/src/+/HEAD/chrome/common/chrome_switches.cc
# https://github.com/GoogleChrome/chrome-launcher/blob/main/docs/chrome-flags-for-tools.md
# https://peter.sh/experiments/chromium-command-line-switches/

# Seed the profile with DevTools preferences before Chrome starts.
# This sets: dock position = bottom, default panel = network.
# Chrome stores these in <user-data-dir>/Default/Preferences.
seed_devtools_preferences() {
  local prefs='{"devtools":{"preferences":{"currentDockState":"\"bottom\"","panel-selected-tab":"\"network\""}}}'

  # Seed both Default and Guest Profile — Chrome uses Guest Profile when
  # launched with --guest, and Default otherwise.
  for profile_name in "Default" "Guest Profile"; do
    local prefs_dir="${chrome_dir}/${profile_name}"
    mkdir -p "${prefs_dir}"
    echo "${prefs}" > "${prefs_dir}/Preferences"
  done
}

# TODO(bt): Math to determine better window placement.

# Flags reference:
#   --auto-open-devtools-for-tabs           Open DevTools automatically for every tab on launch.
#                                           Dock position and default panel are set via seeded
#                                           preferences (see seed_devtools_preferences above).
#   --allow-running-insecure-content        Allow HTTPS pages to load HTTP resources (mixed content).
#   --disable-features=ChromeLabs,          Disable Chrome Labs experiments UI and the
#     DefaultBrowserPrompt                  feature-flag-based default browser prompt.
#   --disable-site-isolation-trials         Disable site isolation (allows cross-origin iframes
#                                           to share process, useful for local dev).
#   --disable-web-security                  Disable same-origin policy. Required for local dev
#                                           where the frontend talks to a different-origin API.
#   --ignore-certificate-errors             Accept self-signed / invalid TLS certs.
#   --no-default-browser-check              Skip the "set as default browser" check on startup.
#   --no-first-run                          Suppress the "Welcome to Google Chrome" first-run
#                                           dialog (default browser checkbox, crash reporting, etc.).
#   --install-autogenerated-theme           Set a custom window color so the dev browser is
#                                           visually distinct from your normal Chrome.
#   --unsafely-treat-insecure-origin-as-secure
#                                           Treat the given HTTP origin as secure. Required for
#                                           APIs like getUserMedia() / navigator.mediaDevices
#                                           which need a "secure context".
#   --user-data-dir                         Use a throwaway profile directory so dev sessions
#                                           don't pollute your real Chrome profile.
#   --guest                                 (Mac only) Launch in guest mode — no Google login screen.
#   --window-position / --window-size       Place the dev window predictably on screen.

launch_linux() {
  seed_devtools_preferences
  chromium \
    --auto-open-devtools-for-tabs \
    --allow-running-insecure-content \
    --disable-features=ChromeLabs,DefaultBrowserPrompt \
    --disable-site-isolation-trials \
    --disable-web-security \
    --ignore-certificate-errors \
    --no-default-browser-check \
    --no-first-run \
    --install-autogenerated-theme="100,150,255" \
    --unsafely-treat-insecure-origin-as-secure="http://localhost:5173" \
    --user-data-dir="${chrome_dir}" \
    --window-position=1200,300 \
    --window-size=1500,1700 \
    http://localhost:5173
}

launch_mac() {
  seed_devtools_preferences
  open -na "Google Chrome" --args \
    --auto-open-devtools-for-tabs \
    --disable-features=ChromeLabs,DefaultBrowserPrompt \
    --disable-site-isolation-trials \
    --disable-web-security \
    --ignore-certificate-errors \
    --no-default-browser-check \
    --no-first-run \
    --install-autogenerated-theme="100,150,255" \
    --unsafely-treat-insecure-origin-as-secure="http://localhost:5173" \
    --user-data-dir="${chrome_dir}" \
    --window-position=1200,300 \
    --window-size=1500,1700 \
    --guest \
    http://localhost:5173
}

case $OSTYPE in 
  linux*)
    launch_linux
  ;; 
  darwin*)
    launch_mac
  ;; 
  *)
    echo "Unknown OS"
  ;; 
esac