callRunner: Use PowerShell to run commands on Windows (#3006)

* callRunner: Use PowerShell to run commands on Windows

PowerShell's `Start-Process` cmdlet & its `-Wait` parameter are used to wait
for a process tree to exit. This means we can now accurately track the "Playing"
 status of games on Windows.

* Properly quote runner path

* Simplify argument quoting a bit

There's no need to do different things depending on whether the argument
 contains a space, we can just always use the "longer" triple-quote form

* Only try to run PowerShell if it's available

src/backend/launcher.ts

@@ -26,6 +26,7 @@ import {
   flatPakHome,
   isLinux,
   isMac,
+  isWindows,
   isSteamDeckGameMode,
   runtimePath,
   userHome
@@ -945,6 +946,8 @@ interface RunnerProps {
 
 const commandsRunning = {}
 
+let shouldUsePowerShell: boolean | null = null
+
 function appNameFromCommandParts(commandParts: string[], runner: Runner) {
   let appNameIndex = -1
   let idx = -1
@@ -993,13 +996,34 @@ async function callRunner(
   runner: RunnerProps,
   options?: CallRunnerOptions
 ): Promise<ExecResult> {
-  const fullRunnerPath = join(runner.dir, runner.bin)
   const appName = appNameFromCommandParts(commandParts, runner.name)
 
   // Necessary to get rid of possible undefined or null entries, else
   // TypeError is triggered
   commandParts = commandParts.filter(Boolean)
 
+  let bin = runner.bin
+  let fullRunnerPath = join(runner.dir, bin)
+
+  // On Windows: Use PowerShell's `Start-Process` to wait for the process and
+  // its children to exit, provided PowerShell is available
+  if (shouldUsePowerShell === null)
+    shouldUsePowerShell =
+      isWindows && !!(await searchForExecutableOnPath('powershell'))
+
+  if (shouldUsePowerShell) {
+    const argsAsString = commandParts.map((part) => `"\`"${part}\`""`).join(',')
+    commandParts = [
+      'Start-Process',
+      `"\`"${fullRunnerPath}\`""`,
+      '-Wait',
+      '-ArgumentList',
+      argsAsString,
+      '-NoNewWindow'
+    ]
+    bin = fullRunnerPath = 'powershell'
+  }
+
   const safeCommand = getRunnerCallWithoutCredentials(
     [...commandParts],
     options?.env,
@@ -1032,8 +1056,6 @@ async function callRunner(
     }
   }
 
-  const bin = runner.bin
-
   // check if the same command is currently running
   // if so, return the same promise instead of running it again
   const key = [runner.name, commandParts].join(' ')
@@ -1198,11 +1220,25 @@ function getRunnerCallWithoutCredentials(
   const modifiedCommand = [...command]
   // Redact sensitive arguments (Authorization Code for Legendary, token for GOGDL)
   for (const sensitiveArg of ['--code', '--token']) {
-    const sensitiveArgIndex = modifiedCommand.indexOf(sensitiveArg)
-    if (sensitiveArgIndex === -1) {
-      continue
+    // PowerShell's argument formatting is quite different, instead of having
+    // arguments as members of `command`, they're all in one specific member
+    // (the one after "-ArgumentList")
+    if (runnerPath === 'powershell') {
+      const argumentListIndex = modifiedCommand.indexOf('-ArgumentList') + 1
+      if (!argumentListIndex) continue
+      modifiedCommand[argumentListIndex] = modifiedCommand[
+        argumentListIndex
+      ].replace(
+        new RegExp(`"${sensitiveArg}","(.*?)"`),
+        `"${sensitiveArg}","<redacted>"`
+      )
+    } else {
+      const sensitiveArgIndex = modifiedCommand.indexOf(sensitiveArg)
+      if (sensitiveArgIndex === -1) {
+        continue
+      }
+      modifiedCommand[sensitiveArgIndex + 1] = '<redacted>'
     }
-    modifiedCommand[sensitiveArgIndex + 1] = '<redacted>'
   }
 
   const formattedEnvVars: string[] = []