Test both light and dark themes

Author: chrisbanes

lib/src/androidTest/AndroidManifest.xml

@@ -22,7 +22,11 @@
     <application>
 
         <activity
-            android:name=".MdcActivity"
+            android:name=".LightMdcActivity"
+            android:theme="@style/Theme.MdcThemeTest" />
+
+        <activity
+            android:name=".DarkMdcActivity"
             android:theme="@style/Theme.MdcThemeTest" />
 
         <activity

lib/src/androidTest/java/com/google/android/material/composethemeadapter/MdcActivity.kt renamed to lib/src/androidTest/java/com/google/android/material/composethemeadapter/DarkMdcActivity.kt

@@ -16,6 +16,16 @@
 
 package com.google.android.material.composethemeadapter
 
+import android.content.Context
 import androidx.appcompat.app.AppCompatActivity
+import androidx.appcompat.app.AppCompatDelegate
 
-class MdcActivity : AppCompatActivity()
+/**
+ * An [AppCompatActivity] which forces the night mode to 'dark theme'.
+ */
+class DarkMdcActivity : AppCompatActivity() {
+    override fun attachBaseContext(newBase: Context) {
+        delegate.localNightMode = AppCompatDelegate.MODE_NIGHT_YES
+        super.attachBaseContext(newBase)
+    }
+}

lib/src/androidTest/java/com/google/android/material/composethemeadapter/DarkTheme.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2020 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
+ *
+ *      https://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 com.google.android.material.composethemeadapter
+
+import android.content.Context
+import android.content.res.Configuration
+
+/**
+ * This allows us to check whether this [Context]s resource configuration is in 'night mode',
+ * which is also known as dark theme.
+ */
+fun Context.isInDarkTheme(): Boolean {
+    return resources.configuration.uiMode and
+        Configuration.UI_MODE_NIGHT_MASK == Configuration.UI_MODE_NIGHT_YES
+}

lib/src/androidTest/java/com/google/android/material/composethemeadapter/LightMdcActivity.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2020 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
+ *
+ *      https://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 com.google.android.material.composethemeadapter
+
+import android.content.Context
+import androidx.appcompat.app.AppCompatActivity
+import androidx.appcompat.app.AppCompatDelegate
+
+/**
+ * An [AppCompatActivity] which forces the night mode to 'light theme'.
+ */
+class LightMdcActivity : AppCompatActivity() {
+    override fun attachBaseContext(newBase: Context) {
+        delegate.localNightMode = AppCompatDelegate.MODE_NIGHT_NO
+        super.attachBaseContext(newBase)
+    }
+}

lib/src/androidTest/java/com/google/android/material/composethemeadapter/MdcThemeTest.kt

@@ -16,12 +16,13 @@
 
 package com.google.android.material.composethemeadapter
 
-import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.appcompat.app.AppCompatActivity
 import androidx.compose.foundation.shape.CornerSize
 import androidx.compose.foundation.shape.CutCornerShape
 import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.MaterialTheme
 import androidx.compose.ui.geometry.Size
+import androidx.compose.ui.platform.ContextAmbient
 import androidx.compose.ui.platform.DensityAmbient
 import androidx.compose.ui.res.colorResource
 import androidx.compose.ui.text.font.asFontFamily
@@ -32,8 +33,9 @@ import androidx.compose.ui.unit.TextUnit
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.em
 import androidx.compose.ui.unit.sp
+import androidx.test.ext.junit.rules.ActivityScenarioRule
 import androidx.test.filters.MediumTest
-import androidx.ui.test.android.createAndroidComposeRule
+import androidx.ui.test.android.AndroidComposeTestRule
 import com.google.android.material.composethemeadapter.test.R
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertNotNull
@@ -42,13 +44,21 @@ import org.junit.Assert.assertTrue
 import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
-import org.junit.runners.JUnit4
+import org.junit.runners.Parameterized
 
 @MediumTest
-@RunWith(JUnit4::class)
-class MdcThemeTest {
+@RunWith(Parameterized::class)
+class MdcThemeTest<T : AppCompatActivity>(activityClass: Class<T>) {
+    companion object {
+        @JvmStatic
+        @Parameterized.Parameters
+        fun activities() = listOf(DarkMdcActivity::class.java, LightMdcActivity::class.java)
+    }
+
+    private val activityRule = ActivityScenarioRule<T>(activityClass)
+
     @get:Rule
-    val composeTestRule = createAndroidComposeRule<MdcActivity>()
+    val composeTestRule = AndroidComposeTestRule(activityRule)
 
     @Test
     fun colors() = composeTestRule.setContent {
@@ -61,11 +71,14 @@ class MdcThemeTest {
 
             assertEquals(colorResource(R.color.dark_golden_rod), color.secondary)
             assertEquals(colorResource(R.color.slate_gray), color.onSecondary)
-            if (!isSystemInDarkTheme()) {
-                assertEquals(colorResource(R.color.blue_violet), color.secondaryVariant)
-            } else {
+
+            // We don't check isSystemInDarkTheme() here since that only checks the system
+            // dark theme setting: https://issuetracker.google.com/163103826
+            if (ContextAmbient.current.isInDarkTheme()) {
                 // In dark theme secondaryVariant is ignored and always return secondary
                 assertEquals(colorResource(R.color.dark_golden_rod), color.secondaryVariant)
+            } else {
+                assertEquals(colorResource(R.color.blue_violet), color.secondaryVariant)
             }
 
             assertEquals(colorResource(R.color.spring_green), color.surface)