Add support for theme in FragmentScenario

Change-Id: I88ad233269b5a93e0c4ae81a265020eb74c3b70b
Test: ./gradlew fragment-testing:connectedCheck
fixes: 119054431

8 files changed, 224 insertions, 28 deletions

diff --git a/fragment/testing/api/1.1.0-alpha03.txt b/fragment/testing/api/1.1.0-alpha03.txt
index 2ad98867f97..8c83aa33862 100644
--- a/fragment/testing/api/1.1.0-alpha03.txt
+++ b/fragment/testing/api/1.1.0-alpha03.txt
@@ -5,9 +5,11 @@ package androidx.fragment.app.testing {
     method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launch(Class<F>);
     method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launch(Class<F>, android.os.Bundle?);
     method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launch(Class<F>, android.os.Bundle?, androidx.fragment.app.FragmentFactory?);
+    method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launch(Class<F>, android.os.Bundle?, int, androidx.fragment.app.FragmentFactory?);
     method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launchInContainer(Class<F>);
     method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launchInContainer(Class<F>, android.os.Bundle?);
     method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launchInContainer(Class<F>, android.os.Bundle?, androidx.fragment.app.FragmentFactory?);
+    method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launchInContainer(Class<F>, android.os.Bundle?, int, androidx.fragment.app.FragmentFactory?);
     method public androidx.fragment.app.testing.FragmentScenario<F> moveToState(androidx.lifecycle.Lifecycle.State);
     method public androidx.fragment.app.testing.FragmentScenario<F> onFragment(androidx.fragment.app.testing.FragmentScenario.FragmentAction<F>);
     method public androidx.fragment.app.testing.FragmentScenario<F> recreate();
diff --git a/fragment/testing/api/current.txt b/fragment/testing/api/current.txt
index 2ad98867f97..8c83aa33862 100644
--- a/fragment/testing/api/current.txt
+++ b/fragment/testing/api/current.txt
@@ -5,9 +5,11 @@ package androidx.fragment.app.testing {
     method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launch(Class<F>);
     method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launch(Class<F>, android.os.Bundle?);
     method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launch(Class<F>, android.os.Bundle?, androidx.fragment.app.FragmentFactory?);
+    method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launch(Class<F>, android.os.Bundle?, int, androidx.fragment.app.FragmentFactory?);
     method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launchInContainer(Class<F>);
     method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launchInContainer(Class<F>, android.os.Bundle?);
     method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launchInContainer(Class<F>, android.os.Bundle?, androidx.fragment.app.FragmentFactory?);
+    method public static <F extends androidx.fragment.app.Fragment> androidx.fragment.app.testing.FragmentScenario<F> launchInContainer(Class<F>, android.os.Bundle?, int, androidx.fragment.app.FragmentFactory?);
     method public androidx.fragment.app.testing.FragmentScenario<F> moveToState(androidx.lifecycle.Lifecycle.State);
     method public androidx.fragment.app.testing.FragmentScenario<F> onFragment(androidx.fragment.app.testing.FragmentScenario.FragmentAction<F>);
     method public androidx.fragment.app.testing.FragmentScenario<F> recreate();
diff --git a/fragment/testing/src/androidTest/java/androidx/fragment/app/testing/FragmentScenarioTest.kt b/fragment/testing/src/androidTest/java/androidx/fragment/app/testing/FragmentScenarioTest.kt
index b79067662ba..0413ee2783f 100644
--- a/fragment/testing/src/androidTest/java/androidx/fragment/app/testing/FragmentScenarioTest.kt
+++ b/fragment/testing/src/androidTest/java/androidx/fragment/app/testing/FragmentScenarioTest.kt
@@ -18,6 +18,7 @@ package androidx.fragment.app.testing
 
 import android.os.Bundle
 import androidx.fragment.app.FragmentFactory
+import androidx.fragment.testing.test.R.style.ThemedFragmentTheme
 import androidx.lifecycle.Lifecycle.State
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import com.google.common.truth.Truth.assertThat
@@ -69,6 +70,17 @@ class FragmentScenarioTest {
     }
 
     @Test
+    fun launchThemedFragment() {
+        with(launchFragment<ThemedFragment>(themeResId = ThemedFragmentTheme)) {
+            onFragment { fragment ->
+                assertThat(fragment.state).isEqualTo(State.RESUMED)
+                assertThat(fragment.isViewAttachedToWindow).isFalse()
+                assertThat(fragment.hasThemedFragmentTheme()).isTrue()
+            }
+        }
+    }
+
+    @Test
     fun launchFragmentInContainer() {
         with(launchFragmentInContainer<StateRecordingFragment>()) {
             onFragment { fragment ->
@@ -92,10 +104,21 @@ class FragmentScenarioTest {
     }
 
     @Test
+    fun launchThemedFragmentInContainer() {
+        with(launchFragmentInContainer<ThemedFragment>(themeResId = ThemedFragmentTheme)) {
+            onFragment { fragment ->
+                assertThat(fragment.state).isEqualTo(State.RESUMED)
+                assertThat(fragment.isViewAttachedToWindow).isTrue()
+                assertThat(fragment.hasThemedFragmentTheme()).isTrue()
+            }
+        }
+    }
+
+    @Test
     fun launchFragmentWithFragmentFactory() {
         with(
-            launchFragment<NoDefaultConstructorFragment>(/*fragmentArgs=*/null,
-                NoDefaultConstructorFragmentFactory("my constructor arg")
+            launchFragment<NoDefaultConstructorFragment>(
+                factory = NoDefaultConstructorFragmentFactory("my constructor arg")
             )
         ) {
             onFragment { fragment ->
@@ -109,8 +132,8 @@ class FragmentScenarioTest {
     @Test
     fun launchInContainerFragmentWithFragmentFactory() {
         with(
-            launchFragmentInContainer<NoDefaultConstructorFragment>(/*fragmentArgs=*/null,
-                NoDefaultConstructorFragmentFactory("my constructor arg")
+            launchFragmentInContainer<NoDefaultConstructorFragment>(
+                factory = NoDefaultConstructorFragmentFactory("my constructor arg")
             )
         ) {
             onFragment { fragment ->
@@ -124,7 +147,7 @@ class FragmentScenarioTest {
     @Test
     fun launchWithCrossInlineFactoryFunction() {
         var numberOfInstantiations = 0
-        with(launchFragment(/*fragmentArgs=*/null) {
+        with(launchFragment {
             numberOfInstantiations++
             NoDefaultConstructorFragment("my constructor arg")
         }) {
@@ -140,7 +163,7 @@ class FragmentScenarioTest {
     @Test
     fun launchInContainerWithCrossInlineFactoryFunction() {
         var numberOfInstantiations = 0
-        with(launchFragmentInContainer(/*fragmentArgs=*/null) {
+        with(launchFragmentInContainer {
             numberOfInstantiations++
             NoDefaultConstructorFragment("my constructor arg")
         }) {
@@ -328,7 +351,7 @@ class FragmentScenarioTest {
     @Test
     fun recreateFragmentWithFragmentFactory() {
         var numberOfInstantiations = 0
-        with(launchFragment(/*fragmentArgs=*/null) {
+        with(launchFragment {
             numberOfInstantiations++
             NoDefaultConstructorFragment("my constructor arg")
         }) {
@@ -347,4 +370,23 @@ class FragmentScenarioTest {
             }
         }
     }
+
+    @Test
+    fun recreateThemedFragment() {
+        with(launchFragmentInContainer<ThemedFragment>(themeResId = ThemedFragmentTheme)) {
+            onFragment { fragment ->
+                assertThat(fragment.state).isEqualTo(State.RESUMED)
+                assertThat(fragment.isViewAttachedToWindow).isTrue()
+                assertThat(fragment.hasThemedFragmentTheme()).isTrue()
+                assertThat(fragment.numberOfRecreations).isEqualTo(0)
+            }
+            recreate()
+            onFragment { fragment ->
+                assertThat(fragment.state).isEqualTo(State.RESUMED)
+                assertThat(fragment.isViewAttachedToWindow).isTrue()
+                assertThat(fragment.hasThemedFragmentTheme()).isTrue()
+                assertThat(fragment.numberOfRecreations).isEqualTo(1)
+            }
+        }
+    }
 }
diff --git a/fragment/testing/src/androidTest/java/androidx/fragment/app/testing/ThemedFragment.kt b/fragment/testing/src/androidTest/java/androidx/fragment/app/testing/ThemedFragment.kt
new file mode 100644
index 00000000000..40dda590928
--- /dev/null
+++ b/fragment/testing/src/androidTest/java/androidx/fragment/app/testing/ThemedFragment.kt
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package androidx.fragment.app.testing
+
+import androidx.fragment.testing.test.R
+
+/**
+ * A minimum example fragment which requires a specific theme.
+ * For example, if your fragment uses material components views, those views require
+ * Theme.MaterialComponents.
+ */
+class ThemedFragment : StateRecordingFragment() {
+    fun hasThemedFragmentTheme(): Boolean {
+        val attrs =
+            context!!.theme.obtainStyledAttributes(intArrayOf(R.attr.exampleRequiredAttribute))
+        try {
+            return attrs.hasValue(R.styleable.ThemedFragmentTheme_exampleRequiredAttribute)
+        } finally {
+            attrs.recycle()
+        }
+    }
+}
\ No newline at end of file
diff --git a/fragment/testing/src/androidTest/res/values/attrs.xml b/fragment/testing/src/androidTest/res/values/attrs.xml
new file mode 100644
index 00000000000..cb748bfb00e
--- /dev/null
+++ b/fragment/testing/src/androidTest/res/values/attrs.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright 2018 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+<resources xmlns:tools="http://schemas.android.com/tools">
+    <declare-styleable name="ThemedFragmentTheme">
+        <attr name="exampleRequiredAttribute" format="boolean"/>
+    </declare-styleable>
+</resources>
\ No newline at end of file
diff --git a/fragment/testing/src/androidTest/res/values/styles.xml b/fragment/testing/src/androidTest/res/values/styles.xml
new file mode 100644
index 00000000000..abb88feb380
--- /dev/null
+++ b/fragment/testing/src/androidTest/res/values/styles.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright 2018 The Android Open Source Project
+  ~
+  ~ Licensed under the Apache License, Version 2.0 (the "License");
+  ~ you may not use this file except in compliance with the License.
+  ~ You may obtain a copy of the License at
+  ~
+  ~      http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing, software
+  ~ distributed under the License is distributed on an "AS IS" BASIS,
+  ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  ~ See the License for the specific language governing permissions and
+  ~ limitations under the License.
+  -->
+<resources xmlns:tools="http://schemas.android.com/tools">
+    <style name="ThemedFragmentTheme" parent="android:Theme">
+        <item name="exampleRequiredAttribute">true</item>
+    </style>
+</resources>
\ No newline at end of file
diff --git a/fragment/testing/src/main/java/androidx/fragment/app/testing/FragmentScenario.java b/fragment/testing/src/main/java/androidx/fragment/app/testing/FragmentScenario.java
index 0eccbbf6af4..b146da77568 100644
--- a/fragment/testing/src/main/java/androidx/fragment/app/testing/FragmentScenario.java
+++ b/fragment/testing/src/main/java/androidx/fragment/app/testing/FragmentScenario.java
@@ -19,7 +19,10 @@ package androidx.fragment.app.testing;
 import static androidx.annotation.RestrictTo.Scope.LIBRARY;
 import static androidx.core.util.Preconditions.checkNotNull;
 import static androidx.core.util.Preconditions.checkState;
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
 
+import android.content.ComponentName;
+import android.content.Intent;
 import android.os.Bundle;
 
 import androidx.annotation.NonNull;
@@ -29,6 +32,7 @@ import androidx.core.util.Preconditions;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentActivity;
 import androidx.fragment.app.FragmentFactory;
+import androidx.fragment.testing.R;
 import androidx.lifecycle.Lifecycle.State;
 import androidx.lifecycle.ViewModel;
 import androidx.lifecycle.ViewModelProvider;
@@ -63,8 +67,17 @@ public final class FragmentScenario<F extends Fragment> {
      */
     @RestrictTo(LIBRARY)
     public static class EmptyFragmentActivity extends FragmentActivity {
+
+        @NonNull
+        public static final String THEME_EXTRAS_BUNDLE_KEY =
+                "androidx.fragment.app.testing.FragmentScenario.EmptyFragmentActivity"
+                        + ".THEME_EXTRAS_BUNDLE_KEY";
+
         @Override
         protected void onCreate(@Nullable Bundle savedInstanceState) {
+            setTheme(getIntent().getIntExtra(THEME_EXTRAS_BUNDLE_KEY,
+                    R.style.FragmentScenarioEmptyFragmentActivityTheme));
+
             // Checks if we have a custom FragmentFactory and set it.
             ViewModelProvider viewModelProvider = new ViewModelProvider(
                     this, ViewModelProvider.AndroidViewModelFactory.getInstance(getApplication()));
@@ -158,7 +171,28 @@ public final class FragmentScenario<F extends Fragment> {
     public static <F extends Fragment> FragmentScenario<F> launch(
             @NonNull Class<F> fragmentClass, @Nullable Bundle fragmentArgs,
             @Nullable FragmentFactory factory) {
-        return internalLaunch(fragmentClass, fragmentArgs, factory, /*containerViewId=*/ 0);
+        return launch(fragmentClass, fragmentArgs,
+                R.style.FragmentScenarioEmptyFragmentActivityTheme, factory);
+    }
+
+    /**
+     * Launches a Fragment with given arguments hosted by an empty {@link FragmentActivity} themed
+     * by {@code themeResId}, using the given {@link FragmentFactory} and waits for it to reach the
+     * resumed state.
+     * <p>
+     * This method cannot be called from the main thread.
+     *
+     * @param fragmentClass a fragment class to instantiate
+     * @param fragmentArgs a bundle to passed into fragment
+     * @param themeResId a style resource id to be set to the host activity's theme
+     * @param factory a fragment factory to use or null to use default factory
+     */
+    @NonNull
+    public static <F extends Fragment> FragmentScenario<F> launch(
+            @NonNull Class<F> fragmentClass, @Nullable Bundle fragmentArgs,
+            int themeResId, @Nullable FragmentFactory factory) {
+        return internalLaunch(fragmentClass, fragmentArgs, themeResId, factory,
+                /*containerViewId=*/ 0);
     }
 
     /**
@@ -177,8 +211,8 @@ public final class FragmentScenario<F extends Fragment> {
 
     /**
      * Launches a Fragment in the Activity's root view container {@code android.R.id.content}, with
-     * given arguments hosted by an empty {@link FragmentActivity} using the given
-     * {@link FragmentFactory} and waits for it to reach the resumed state.
+     * given arguments hosted by an empty {@link FragmentActivity} and waits for it to reach the
+     * resumed state.
      * <p>
      * This method cannot be called from the main thread.
      *
@@ -193,8 +227,8 @@ public final class FragmentScenario<F extends Fragment> {
 
     /**
      * Launches a Fragment in the Activity's root view container {@code android.R.id.content}, with
-     * given arguments hosted by an empty {@link FragmentActivity} and waits for it to reach the
-     * resumed state.
+     * given arguments hosted by an empty {@link FragmentActivity} using the given
+     * {@link FragmentFactory} and waits for it to reach the resumed state.
      * <p>
      * This method cannot be called from the main thread.
      *
@@ -206,17 +240,45 @@ public final class FragmentScenario<F extends Fragment> {
     public static <F extends Fragment> FragmentScenario<F> launchInContainer(
             @NonNull Class<F> fragmentClass, @Nullable Bundle fragmentArgs,
             @Nullable FragmentFactory factory) {
+        return launchInContainer(
+                fragmentClass, fragmentArgs, R.style.FragmentScenarioEmptyFragmentActivityTheme,
+                factory);
+    }
+
+    /**
+     * Launches a Fragment in the Activity's root view container {@code android.R.id.content}, with
+     * given arguments hosted by an empty {@link FragmentActivity} themed by {@code themeResId},
+     * using the given {@link FragmentFactory} and waits for it to reach the resumed state.
+     * <p>
+     * This method cannot be called from the main thread.
+     *
+     * @param fragmentClass a fragment class to instantiate
+     * @param fragmentArgs a bundle to passed into fragment
+     * @param themeResId a style resource id to be set to the host activity's theme
+     * @param factory a fragment factory to use or null to use default factory
+     */
+    @NonNull
+    public static <F extends Fragment> FragmentScenario<F> launchInContainer(
+            @NonNull Class<F> fragmentClass, @Nullable Bundle fragmentArgs,
+            int themeResId, @Nullable FragmentFactory factory) {
         return internalLaunch(
-                fragmentClass, fragmentArgs, factory, /*containerViewId=*/ android.R.id.content);
+                fragmentClass, fragmentArgs, themeResId, factory,
+                /*containerViewId=*/ android.R.id.content);
     }
 
     @NonNull
     private static <F extends Fragment> FragmentScenario<F> internalLaunch(
             @NonNull final Class<F> fragmentClass, final @Nullable Bundle fragmentArgs,
-            @Nullable final FragmentFactory factory, final int containerViewId) {
+            final int themeResId, @Nullable final FragmentFactory factory,
+            final int containerViewId) {
+        Intent startActivityIntent =
+                Intent.makeMainActivity(
+                        new ComponentName(getApplicationContext(),
+                                EmptyFragmentActivity.class))
+                        .putExtra(EmptyFragmentActivity.THEME_EXTRAS_BUNDLE_KEY, themeResId);
         FragmentScenario<F> scenario = new FragmentScenario<>(
                 fragmentClass, factory,
-                ActivityScenario.launch(EmptyFragmentActivity.class));
+                ActivityScenario.<EmptyFragmentActivity>launch(startActivityIntent));
         scenario.mActivityScenario.onActivity(
                 new ActivityScenario.ActivityAction<EmptyFragmentActivity>() {
                     @Override
diff --git a/fragment/testing/src/main/java/androidx/fragment/app/testing/FragmentScenario.kt b/fragment/testing/src/main/java/androidx/fragment/app/testing/FragmentScenario.kt
index 92463869d7b..48da729f6fd 100644
--- a/fragment/testing/src/main/java/androidx/fragment/app/testing/FragmentScenario.kt
+++ b/fragment/testing/src/main/java/androidx/fragment/app/testing/FragmentScenario.kt
@@ -20,6 +20,7 @@ import android.os.Bundle
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.FragmentActivity
 import androidx.fragment.app.FragmentFactory
+import androidx.fragment.testing.R
 
 /**
  * Launches a Fragment with given arguments hosted by an empty [FragmentActivity] using
@@ -28,12 +29,14 @@ import androidx.fragment.app.FragmentFactory
  * This method cannot be called from the main thread.
  *
  * @param fragmentArgs a bundle to passed into fragment
+ * @param themeResId a style resource id to be set to the host activity's theme
  * @param factory a fragment factory to use or null to use default factory
  */
 inline fun <reified F : Fragment> launchFragment(
     fragmentArgs: Bundle? = null,
+    themeResId: Int = R.style.FragmentScenarioEmptyFragmentActivityTheme,
     factory: FragmentFactory? = null
-) = FragmentScenario.launch(F::class.java, fragmentArgs, factory)
+) = FragmentScenario.launch(F::class.java, fragmentArgs, themeResId, factory)
 
 /**
  * Launches a Fragment with given arguments hosted by an empty [FragmentActivity] using
@@ -42,12 +45,14 @@ inline fun <reified F : Fragment> launchFragment(
  * This method cannot be called from the main thread.
  *
  * @param fragmentArgs a bundle to passed into fragment
+ * @param themeResId a style resource id to be set to the host activity's theme
  * @param instantiate method which will be used to instantiate the Fragment.
  */
 inline fun <reified F : Fragment> launchFragment(
     fragmentArgs: Bundle? = null,
+    themeResId: Int = R.style.FragmentScenarioEmptyFragmentActivityTheme,
     crossinline instantiate: (args: Bundle?) -> F
-) = FragmentScenario.launch(F::class.java, fragmentArgs, object : FragmentFactory() {
+) = FragmentScenario.launch(F::class.java, fragmentArgs, themeResId, object : FragmentFactory() {
     override fun instantiate(
         classLoader: ClassLoader,
         className: String,
@@ -66,12 +71,14 @@ inline fun <reified F : Fragment> launchFragment(
  * This method cannot be called from the main thread.
  *
  * @param fragmentArgs a bundle to passed into fragment
+ * @param themeResId a style resource id to be set to the host activity's theme
  * @param factory a fragment factory to use or null to use default factory
  */
 inline fun <reified F : Fragment> launchFragmentInContainer(
     fragmentArgs: Bundle? = null,
+    themeResId: Int = R.style.FragmentScenarioEmptyFragmentActivityTheme,
     factory: FragmentFactory? = null
-) = FragmentScenario.launchInContainer(F::class.java, fragmentArgs, factory)
+) = FragmentScenario.launchInContainer(F::class.java, fragmentArgs, themeResId, factory)
 
 /**
  * Launches a Fragment in the Activity's root view container `android.R.id.content`, with
@@ -82,20 +89,23 @@ inline fun <reified F : Fragment> launchFragmentInContainer(
  * This method cannot be called from the main thread.
  *
  * @param fragmentArgs a bundle to passed into fragment
+ * @param themeResId a style resource id to be set to the host activity's theme
  * @param instantiate method which will be used to instantiate the Fragment. This is a
  * simplification of the [FragmentFactory] interface for cases where only a single class
  * needs a custom constructor called.
  */
 inline fun <reified F : Fragment> launchFragmentInContainer(
     fragmentArgs: Bundle? = null,
+    themeResId: Int = R.style.FragmentScenarioEmptyFragmentActivityTheme,
     crossinline instantiate: (args: Bundle?) -> F
-) = FragmentScenario.launchInContainer(F::class.java, fragmentArgs, object : FragmentFactory() {
-    override fun instantiate(
-        classLoader: ClassLoader,
-        className: String,
-        args: Bundle?
-    ) = when (className) {
-        F::class.java.name -> instantiate(args)
-        else -> super.instantiate(classLoader, className, args)
-    }
-})
+) = FragmentScenario.launchInContainer(F::class.java, fragmentArgs, themeResId,
+    object : FragmentFactory() {
+        override fun instantiate(
+            classLoader: ClassLoader,
+            className: String,
+            args: Bundle?
+        ) = when (className) {
+            F::class.java.name -> instantiate(args)
+            else -> super.instantiate(classLoader, className, args)
+        }
+    })