Fix inventory tests

app/src/androidTest/java/org/tasks/billing/InventoryTest.kt

@@ -60,7 +60,15 @@ class InventoryTest : InjectingTestCase() {
 
     private fun withPurchases(vararg purchases: String) {
         preferences.setPurchases(purchases.toHashSet())
-        inventory = Inventory(context, preferences, signatureVerifier, localBroadcastManager, caldavDao)
+        runOnMainSync {
+            inventory = Inventory(
+                    context,
+                    preferences,
+                    signatureVerifier,
+                    localBroadcastManager,
+                    caldavDao
+            )
+        }
     }
 
     companion object {

app/src/androidTest/java/org/tasks/injection/InjectingTestCase.kt

@@ -2,6 +2,7 @@ package org.tasks.injection
 
 import android.content.Context
 import androidx.test.core.app.ApplicationProvider.getApplicationContext
+import androidx.test.platform.app.InstrumentationRegistry
 import dagger.hilt.android.testing.HiltAndroidRule
 import org.junit.Before
 import org.junit.Rule
@@ -15,6 +16,9 @@ abstract class InjectingTestCase {
         hiltRule.inject()
     }
 
+    protected fun runOnMainSync(runnable: Runnable) =
+            InstrumentationRegistry.getInstrumentation().runOnMainSync(runnable)
+
     protected val context: Context
         get() = getApplicationContext()
 }

app/src/main/java/org/tasks/billing/Inventory.kt

@@ -3,6 +3,7 @@ package org.tasks.billing
 import android.content.Context
 import android.content.Intent
 import android.net.Uri
+import android.os.Handler
 import androidx.lifecycle.MutableLiveData
 import dagger.hilt.android.qualifiers.ApplicationContext
 import org.tasks.BuildConfig
@@ -109,6 +110,12 @@ class Inventory @Inject constructor(
     }
 
     init {
-        verifyAndAdd(preferences.purchases)
+        val runnable = { verifyAndAdd(preferences.purchases) }
+        val mainLooper = context.mainLooper
+        if (mainLooper.isCurrentThread) {
+            runnable()
+        } else {
+            Handler(context.mainLooper).post(runnable)
+        }
     }
 }