[Feature] LogCat array arguments are merged, causing command-line options to fail #3076

Description

When debugging an Android app, I want to view only that app's logs instead of logs from all processes on the device. LogCat supports --pid <pid> for this purpose.

However, setting react-native.android.logCatArguments to ["--pid", "<pid>"] causes the extension to merge the two arguments into --pid,<pid>. LogCat rejects this as an unknown option, preventing the monitor from starting correctly.

Steps to reproduce

1. Open a React Native project in an Extension Development Host window.

2. Start an Android emulator and run the app.

3. Query the running app's PID:

   adb -s emulator-5554 shell pidof com.rn_0_87_1

   In my case, the PID was 16658.

4. To show only this app's logs, open Preferences: Open Workspace Settings (JSON) from the Command Palette and add:

   {
     "react-native.android.logCatArguments": [
       "--pid",
       "16658"
     ]
   }

   Replace 16658 with the current app PID.

5. Save the settings and run React Native: Run React Native LogCat Monitor from the Command Palette.

Expected behavior

The extension passes --pid and 16658 as separate arguments:

["-s", "emulator-5554", "logcat", "--pid", "16658"]

LogCat starts and displays only logs from the specified app process.

Actual behavior

The Output panel shows:

[Debug] Monitoring LogCat for device emulator-5554 with arguments: --pid,16658

Since this log message alone does not distinguish separate array elements, I also inspected the arguments at a breakpoint in AdbHelper.startLogCat():

this.adbExecutable.replace(/"/g, "")
'adb'

JSON.stringify(adbParameters)
'["-s","emulator-5554","logcat","--pid,16658"]'

The extension therefore launches the equivalent of:

adb -s emulator-5554 logcat "--pid,16658"

Verified impact

Running the correct arguments directly in a terminal returns the app's logs:

adb -s emulator-5554 logcat -d --pid 16658

Running the merged argument produces an error:

adb -s emulator-5554 logcat -d "--pid,16658"

logcat: Unknown option '(null)'.

The -d flag is used only for the terminal comparison so the command exits after dumping existing logs.

Cause

In src/extension/android/logCatMonitor.ts, getLogCatArguments() converts the array to a string and then splits it on spaces:

String(this._userProvidedLogCatArguments).split(" ")

JavaScript joins array elements with commas:

["--pid", "16658"] → "--pid,16658" → ["--pid,16658"]

Array inputs should preserve their argument boundaries.