fix(adb): Force-stop the app before each launch and after a run timeout

app-runner/Private/DeviceProviders/AdbProvider.ps1

@@ -53,6 +53,7 @@ class AdbProvider : DeviceProvider {
             # App execution
             'launch'        = @('adb', '-s {0} shell am start -n {1} {2} -W')
             'pidof'         = @('adb', '-s {0} shell pidof {1}')
+            'force-stop'    = @('adb', '-s {0} shell am force-stop {1}')
 
             # Logging
             'logcat'        = @('adb', '-s {0} logcat -d')
@@ -218,6 +219,9 @@ class AdbProvider : DeviceProvider {
 
         $startTime = Get-Date
 
+        # Otherwise `am start` brings a still-running (possibly hung) instance to the front instead of starting a new one.
+        $this.StopApp($packageName)
+
         # Clear logcat before launch
         Write-Debug "$($this.Platform): Clearing logcat"
         $this.InvokeCommand('logcat-clear', @($this.DeviceSerial))
@@ -289,6 +293,10 @@ class AdbProvider : DeviceProvider {
             $logCache = @($this.InvokeCommand('logcat-pid', @($this.DeviceSerial, $appPID)))
             Write-Host "Retrieved $($logCache.Count) log lines" -ForegroundColor Cyan
 
+            if (-not $processExited) {
+                $this.StopApp($packageName)
+            }
+
             Write-Host "Android doesn't report exit codes via adb so exit code is always NULL"
             $exitCode = $null
         }
@@ -308,6 +316,15 @@ class AdbProvider : DeviceProvider {
         }
     }
 
+    [void] StopApp([string]$packageName) {
+        try {
+            $this.InvokeCommand('force-stop', @($this.DeviceSerial, $packageName)) | Out-Null
+        }
+        catch {
+            Write-Warning "$($this.Platform): Failed to force-stop ${packageName}: $_"
+        }
+    }
+
     # Helper method to wait for process with retry
     [string] WaitForProcess([string]$packageName, [int]$timeoutSeconds) {
         Write-Debug "$($this.Platform): Waiting for process: $packageName"

app-runner/Tests/AdbRunApplication.Tests.ps1

@@ -0,0 +1,69 @@
+$ErrorActionPreference = 'Stop'
+
+BeforeAll {
+    . "$PSScriptRoot\..\Private\DeviceProviders\DeviceProvider.ps1"
+    . "$PSScriptRoot\..\Private\DeviceProviders\AdbProvider.ps1"
+
+    Invoke-Expression @'
+class FakeAdbProvider : AdbProvider {
+    [System.Collections.Generic.List[string]]$Calls = [System.Collections.Generic.List[string]]::new()
+    [bool]$Hangs = $false
+    [bool]$ForceStopFails = $false
+    [int]$PidofCalls = 0
+
+    FakeAdbProvider() : base() {
+        $this.DeviceSerial = 'emulator-5554'
+        $this.Timeouts['run-timeout'] = 1
+        $this.Timeouts['pid-retry'] = 1
+        $this.Timeouts['process-check-interval'] = 0
+    }
+
+    [object] InvokeCommand([string]$action, [object[]]$parameters) {
+        $this.Calls.Add($action)
+        switch ($action) {
+            'force-stop' { if ($this.ForceStopFails) { throw 'adb: device offline' } }
+            'launch' { return 'Status: ok' }
+            'pidof' {
+                $this.PidofCalls++
+                if ($this.Hangs -or $this.PidofCalls -eq 1) { return '4056' }
+                return $null
+            }
+            'logcat-pid' { return @('10-20 08:14:04.782  4056  4056 I IL2CPP  : JNI_OnLoad') }
+        }
+        return $null
+    }
+}
+'@
+}
+
+Describe 'AdbProvider.RunApplication' -Tag 'Unit' {
+    It 'Force-stops the package before launching it' {
+        $provider = [FakeAdbProvider]::new()
+
+        $provider.RunApplication('com.example.app/.MainActivity', @(), $null, $null) | Out-Null
+
+        $provider.Calls[0] | Should -Be 'force-stop'
+        $provider.Calls.IndexOf('force-stop') | Should -BeLessThan $provider.Calls.IndexOf('launch')
+        @($provider.Calls | Where-Object { $_ -eq 'force-stop' }).Count | Should -Be 1
+    }
+
+    It 'Force-stops the package after a run timeout, once its logs are read' {
+        $provider = [FakeAdbProvider]::new()
+        $provider.Hangs = $true
+
+        $result = $provider.RunApplication('com.example.app/.MainActivity', @(), $null, $null)
+
+        $provider.Calls[-1] | Should -Be 'force-stop'
+        $provider.Calls[-2] | Should -Be 'logcat-pid'
+        $result.Output | Should -Contain '10-20 08:14:04.782  4056  4056 I IL2CPP  : JNI_OnLoad'
+    }
+
+    It 'Still launches when force-stop fails' {
+        $provider = [FakeAdbProvider]::new()
+        $provider.ForceStopFails = $true
+
+        $provider.RunApplication('com.example.app/.MainActivity', @(), $null, $null) 3>$null | Out-Null
+
+        $provider.Calls | Should -Contain 'launch'
+    }
+}