For mozilla-mobile#13959: change StrictModeManager to class from object.

I originally tried to create this PR leaving this as an object to keep
the change simple but it wasn't worth it - once the object started to
keep state, we'd need to manually reset the state between runs. Also,
the tests were already getting hacky with static mocking so it was
easier to address some of those issues this way too.

app/src/main/java/org/mozilla/fenix/FenixApplication.kt

@@ -40,7 +40,6 @@ import mozilla.components.support.rusthttp.RustHttpConfig
 import mozilla.components.support.rustlog.RustLog
 import mozilla.components.support.utils.logElapsedTime
 import mozilla.components.support.webextensions.WebExtensionSupport
-import org.mozilla.fenix.StrictModeManager.enableStrictMode
 import org.mozilla.fenix.components.Components
 import org.mozilla.fenix.components.metrics.MetricServiceType
 import org.mozilla.fenix.ext.components
@@ -126,7 +125,7 @@ open class FenixApplication : LocaleAwareApplication(), Provider {
             val megazordSetup = setupMegazord()
 
             setDayNightTheme()
-            enableStrictMode(true)
+            components.strictMode.enableStrictMode(true)
             warmBrowsersCache()
 
             // Make sure the engine is initialized and ready to use.

app/src/main/java/org/mozilla/fenix/HomeActivity.kt

@@ -150,7 +150,7 @@ open class HomeActivity : LocaleAwareAppCompatActivity(), NavHostActivity {
     private lateinit var navigationToolbar: Toolbar
 
     final override fun onCreate(savedInstanceState: Bundle?) {
-        StrictModeManager.attachListenerToDisablePenaltyDeath(supportFragmentManager)
+        components.strictMode.attachListenerToDisablePenaltyDeath(supportFragmentManager)
         // There is disk read violations on some devices such as samsung and pixel for android 9/10
         StrictMode.allowThreadDiskReads().resetPoliciesAfter {
             super.onCreate(savedInstanceState)

app/src/main/java/org/mozilla/fenix/StrictModeManager.kt

@@ -9,24 +9,24 @@ import android.os.StrictMode
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.FragmentManager
 
+private const val MANUFACTURE_HUAWEI: String = "HUAWEI"
+private const val MANUFACTURE_ONE_PLUS: String = "OnePlus"
+
 /**
  * Manages strict mode settings for the application.
- *
- * Due to the static dependencies in this class, it's getting hard to test: if this class takes any
- * many more static dependencies, consider switching it, and other code that uses [StrictMode] like
- * [StrictMode.ThreadPolicy].resetPoliciesAfter, to a class with dependency injection.
  */
-object StrictModeManager {
+class StrictModeManager(config: Config) {
+
+    // The expression in this if is duplicated in StrictMode.ThreadPolicy.resetPoliciesAfter
+    // because we don't want to have to pass in a dependency each time the ext fn is called.
+    private val isEnabledByBuildConfig = config.channel.isDebug
 
     /***
      * Enables strict mode for debug purposes. meant to be run only in the main process.
      * @param setPenaltyDeath boolean value to decide setting the penaltyDeath as a penalty.
      */
     fun enableStrictMode(setPenaltyDeath: Boolean) {
-        // The expression in this if is duplicated in StrictMode.ThreadPolicy.resetPoliciesAfter
-        // because the tests break in unexpected ways if the value is shared as a constant in this
-        // class. It wasn't worth the time to address it.
-        if (Config.channel.isDebug) {
+        if (isEnabledByBuildConfig) {
             val threadPolicy = StrictMode.ThreadPolicy.Builder()
                 .detectAll()
                 .penaltyLog()
@@ -67,9 +67,6 @@ object StrictModeManager {
         }, false)
     }
 
-    private const val MANUFACTURE_HUAWEI: String = "HUAWEI"
-    private const val MANUFACTURE_ONE_PLUS: String = "OnePlus"
-
     /**
      * There are certain manufacturers that have custom font classes for the OS systems.
      * These classes violates the [StrictMode] policies on startup. As a workaround, we create

app/src/main/java/org/mozilla/fenix/components/Components.kt

@@ -19,6 +19,7 @@ import mozilla.components.support.migration.state.MigrationStore
 import org.mozilla.fenix.BuildConfig
 import org.mozilla.fenix.Config
 import org.mozilla.fenix.HomeActivity
+import org.mozilla.fenix.StrictModeManager
 import org.mozilla.fenix.components.metrics.AppStartupTelemetry
 import org.mozilla.fenix.ext.settings
 import org.mozilla.fenix.utils.ClipboardHandler
@@ -126,6 +127,7 @@ class Components(private val context: Context) {
     val performance by lazy { PerformanceComponent() }
     val push by lazy { Push(context, analytics.crashReporter) }
     val wifiConnectionMonitor by lazy { WifiConnectionMonitor(context as Application) }
+    val strictMode by lazy { StrictModeManager(Config) }
 
     val settings by lazy { Settings(context) }
 

app/src/test/java/org/mozilla/fenix/StrictModeManagerTest.kt

@@ -11,10 +11,8 @@ import io.mockk.confirmVerified
 import io.mockk.every
 import io.mockk.impl.annotations.MockK
 import io.mockk.mockk
-import io.mockk.mockkObject
 import io.mockk.mockkStatic
 import io.mockk.slot
-import io.mockk.unmockkObject
 import io.mockk.unmockkStatic
 import io.mockk.verify
 import org.junit.After
@@ -26,44 +24,49 @@ import org.mozilla.fenix.helpers.FenixRobolectricTestRunner
 @RunWith(FenixRobolectricTestRunner::class)
 class StrictModeManagerTest {
 
+    private lateinit var debugManager: StrictModeManager
+    private lateinit var releaseManager: StrictModeManager
+
     @MockK(relaxUnitFun = true) private lateinit var fragmentManager: FragmentManager
 
     @Before
     fun setup() {
         MockKAnnotations.init(this)
         mockkStatic(StrictMode::class)
-        mockkObject(Config)
+
+        // These tests log a warning that mockk couldn't set the backing field of Config.channel
+        // but it doesn't seem to impact their correctness so I'm ignoring it.
+        val debugConfig: Config = mockk { every { channel } returns ReleaseChannel.Debug }
+        debugManager = StrictModeManager(debugConfig)
+
+        val releaseConfig: Config = mockk { every { channel } returns ReleaseChannel.Release }
+        releaseManager = StrictModeManager(releaseConfig)
     }
 
     @After
     fun teardown() {
         unmockkStatic(StrictMode::class)
-        unmockkObject(Config)
     }
 
     @Test
     fun `test enableStrictMode in release`() {
-        every { Config.channel } returns ReleaseChannel.Release
-        StrictModeManager.enableStrictMode(false)
-
+        releaseManager.enableStrictMode(false)
         verify(exactly = 0) { StrictMode.setThreadPolicy(any()) }
         verify(exactly = 0) { StrictMode.setVmPolicy(any()) }
     }
 
     @Test
     fun `test enableStrictMode in debug`() {
-        every { Config.channel } returns ReleaseChannel.Debug
-        StrictModeManager.enableStrictMode(false)
-
+        debugManager.enableStrictMode(false)
         verify { StrictMode.setThreadPolicy(any()) }
         verify { StrictMode.setVmPolicy(any()) }
     }
 
     @Test
-    fun `test changeStrictModePolicies`() {
+    fun `test changeStrictModePolicies in debug`() {
         val callbacks = slot<FragmentManager.FragmentLifecycleCallbacks>()
 
-        StrictModeManager.attachListenerToDisablePenaltyDeath(fragmentManager)
+        debugManager.attachListenerToDisablePenaltyDeath(fragmentManager)
         verify { fragmentManager.registerFragmentLifecycleCallbacks(capture(callbacks), false) }
         confirmVerified(fragmentManager)