chrome launch script (#1371)

script/launch_dev_browser.sh

@@ -10,22 +10,60 @@ declare -r chrome_dir="/tmp/chrome/${entropy}"
 # https://github.com/GoogleChrome/chrome-launcher/blob/main/docs/chrome-flags-for-tools.md
 # https://peter.sh/experiments/chromium-command-line-switches/
 
-# NB: Creating the directory first seems to block process start.
-# Perhaps this is the wrong chmod ownership flags.
-#mkdir -p $CHROME_DIR
+# 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\""}}}'
 
-    #--auto-open-devtools-for-tabs="true" \
-    #--devtools-flags="" \
+  # 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 \
+    --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}" \
@@ -35,16 +73,15 @@ launch_linux() {
 }
 
 launch_mac() {
-  # See https://stackoverflow.com/a/58658101
-  # NB: '7001' port is being chosen because something on the system is hogging port 7000.
-  # chrome://flags/#unsafely-treat-insecure-origin-as-secure - allow microphone recording
-  # otherwise getUserMedia() / navigator.mediaDevices will not function
-  # --guest: no Google login screen
+  seed_devtools_preferences
   open -na "Google Chrome" --args \
-    --disable-features=ChromeLabs \
+    --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}" \