Unified emulator settings for Database

firebase-common/src/androidTest/java/com/google/firebase/FirebaseAppTest.java

@@ -14,29 +14,18 @@
 
 package com.google.firebase;
 
-import static com.google.android.gms.common.util.Base64Utils.decodeUrlSafeNoPadding;
-import static com.google.common.truth.Truth.assertThat;
-import static com.google.firebase.common.testutil.Assert.assertThrows;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.never;
-import static org.mockito.Mockito.reset;
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
 import android.content.BroadcastReceiver;
 import android.content.ComponentCallbacks2;
 import android.content.Context;
 import android.content.ContextWrapper;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.os.UserManager;
+
 import androidx.localbroadcastmanager.content.LocalBroadcastManager;
 import androidx.test.InstrumentationRegistry;
 import androidx.test.runner.AndroidJUnit4;
+
 import com.google.android.gms.common.api.internal.BackgroundDetector;
 import com.google.common.base.Defaults;
 import com.google.firebase.auth.FirebaseAuth;
@@ -45,8 +34,18 @@
 import com.google.firebase.components.TestComponentOne;
 import com.google.firebase.components.TestComponentTwo;
 import com.google.firebase.components.TestUserAgentDependentComponent;
+import com.google.firebase.emulators.EmulatedServiceSettings;
+import com.google.firebase.emulators.EmulatorSettings;
+import com.google.firebase.emulators.FirebaseEmulators;
 import com.google.firebase.platforminfo.UserAgentPublisher;
 import com.google.firebase.testing.FirebaseAppRule;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.stubbing.Answer;
+
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
@@ -56,11 +55,19 @@
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
-import org.junit.Before;
-import org.junit.Rule;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.mockito.stubbing.Answer;
+
+import static com.google.android.gms.common.util.Base64Utils.decodeUrlSafeNoPadding;
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.firebase.common.testutil.Assert.assertThrows;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
 /** Unit tests for {@link com.google.firebase.FirebaseApp}. */
 // TODO(arondeak): uncomment lines when Firebase API targets are in integ.
@@ -417,6 +424,43 @@ public void testDirectBoot_shouldPreserveDataCollectionAfterUnlock() {
     assertTrue(firebaseApp.isDataCollectionDefaultEnabled());
   }
 
+  @Test
+  public void testEnableEmulators_shouldAllowDoubleSetBeforeAccess() {
+    Context mockContext = createForwardingMockContext();
+    FirebaseApp firebaseApp = FirebaseApp.initializeApp(mockContext);
+
+    EmulatedServiceSettings databaseSettings =
+        new EmulatedServiceSettings.Builder("10.0.2.2", 9000).build();
+    EmulatorSettings emulatorSettings =
+        new EmulatorSettings.Builder()
+            .addEmulatedService(FirebaseEmulators.DATABASE, databaseSettings)
+            .build();
+
+    // Set twice
+    firebaseApp.enableEmulators(emulatorSettings);
+    firebaseApp.enableEmulators(emulatorSettings);
+  }
+
+  @Test
+  public void testEnableEmulators_shouldThrowIfSetAfterAccess() {
+    Context mockContext = createForwardingMockContext();
+    FirebaseApp firebaseApp = FirebaseApp.initializeApp(mockContext);
+
+    EmulatedServiceSettings databaseSettings =
+        new EmulatedServiceSettings.Builder("10.0.2.2", 9000).build();
+    EmulatorSettings emulatorSettings =
+        new EmulatorSettings.Builder()
+            .addEmulatedService(FirebaseEmulators.DATABASE, databaseSettings)
+            .build();
+    firebaseApp.enableEmulators(emulatorSettings);
+
+    // Access (as if from the Database SDK)
+    firebaseApp.getEmulatorSettings().getServiceSettings(FirebaseEmulators.DATABASE);
+
+    // Try to set again
+    assertThrows(IllegalStateException.class, () -> firebaseApp.enableEmulators(emulatorSettings));
+  }
+
   /** Returns mock context that forwards calls to targetContext and localBroadcastManager. */
   private Context createForwardingMockContext() {
     final UserManager spyUserManager = spy(targetContext.getSystemService(UserManager.class));

firebase-common/src/main/java/com/google/firebase/FirebaseApp.java

@@ -14,8 +14,6 @@
 
 package com.google.firebase;
 
-import static com.google.android.gms.common.util.Base64Utils.encodeUrlSafeNoPadding;
-
 import android.annotation.TargetApi;
 import android.app.Application;
 import android.content.BroadcastReceiver;
@@ -27,11 +25,13 @@
 import android.os.Looper;
 import android.text.TextUtils;
 import android.util.Log;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
 import androidx.collection.ArrayMap;
 import androidx.core.os.UserManagerCompat;
+
 import com.google.android.gms.common.annotation.KeepForSdk;
 import com.google.android.gms.common.api.internal.BackgroundDetector;
 import com.google.android.gms.common.internal.Objects;
@@ -44,12 +44,14 @@
 import com.google.firebase.components.ComponentRegistrar;
 import com.google.firebase.components.ComponentRuntime;
 import com.google.firebase.components.Lazy;
+import com.google.firebase.emulators.EmulatorSettings;
 import com.google.firebase.events.Publisher;
 import com.google.firebase.heartbeatinfo.DefaultHeartBeatInfo;
 import com.google.firebase.internal.DataCollectionConfigStorage;
 import com.google.firebase.platforminfo.DefaultUserAgentPublisher;
 import com.google.firebase.platforminfo.KotlinDetector;
 import com.google.firebase.platforminfo.LibraryVersionComponent;
+
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -59,8 +61,11 @@
 import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
+
 import javax.annotation.concurrent.GuardedBy;
 
+import static com.google.android.gms.common.util.Base64Utils.encodeUrlSafeNoPadding;
+
 /**
  * The entry point of Firebase SDKs. It holds common configuration and state for Firebase APIs. Most
  * applications don't need to directly interact with FirebaseApp.
@@ -109,6 +114,7 @@ public class FirebaseApp {
   private final String name;
   private final FirebaseOptions options;
   private final ComponentRuntime componentRuntime;
+  private EmulatorSettings emulatorSettings;
 
   // Default disabled. We released Firebase publicly without this feature, so making it default
   // enabled is a backwards incompatible change.
@@ -142,6 +148,20 @@ public FirebaseOptions getOptions() {
     return options;
   }
 
+  /**
+   * Returns the specified {@link EmulatorSettings}.
+   *
+   * <p>TODO(samstern): Un-hide this once Firestore, Database, and Functions are implemented
+   *
+   * @hide
+   */
+  @KeepForSdk
+  @Nullable
+  public EmulatorSettings getEmulatorSettings() {
+    checkNotDeleted();
+    return emulatorSettings;
+  }
+
   @Override
   public boolean equals(Object o) {
     if (!(o instanceof FirebaseApp)) {
@@ -305,6 +325,28 @@ public static FirebaseApp initializeApp(
     return firebaseApp;
   }
 
+  /**
+   * Specify which services should access local emulators for this FirebaseApp instance.
+   *
+   * <p>For example, if the {@link EmulatorSettings} contain {@link
+   * com.google.firebase.emulators.EmulatedServiceSettings} for {@link
+   * com.google.firebase.emulators.FirebaseEmulators#FIRESTORE}, then calls to Cloud Firestore will
+   * communicate with the emulator rather than production.
+   *
+   * <p>TODO(samstern): Un-hide this once Firestore, Database, and Functions are implemented
+   *
+   * @param emulatorSettings the emulator settings for all services.
+   * @hide
+   */
+  @KeepForSdk
+  public void enableEmulators(@NonNull EmulatorSettings emulatorSettings) {
+    checkNotDeleted();
+    Preconditions.checkState(
+        !(this.emulatorSettings != null && this.emulatorSettings.isAccessed()),
+        "Cannot enable emulators after Firebase SDKs have already been used.");
+    this.emulatorSettings = emulatorSettings;
+  }
+
   /**
    * Deletes the {@link FirebaseApp} and all its data. All calls to this {@link FirebaseApp}
    * instance will throw once it has been called.

firebase-common/src/main/java/com/google/firebase/emulators/EmulatedServiceSettings.java

@@ -0,0 +1,62 @@
+// Copyright 2020 Google LLC
+//
+// 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 com.google.firebase.emulators;
+
+import androidx.annotation.NonNull;
+
+import com.google.android.gms.common.annotation.KeepForSdk;
+
+/**
+ * Settings to connect a single Firebase service to a local emulator.
+ *
+ * <p>TODO(samstern): Un-hide this once Firestore, Database, and Functions are implemented
+ *
+ * @see EmulatorSettings
+ * @hide
+ */
+@KeepForSdk
+public class EmulatedServiceSettings {
+
+  public static final class Builder {
+
+    private final String host;
+    private final int port;
+
+    /**
+     * Create a new EmulatedServiceSettings builder.
+     *
+     * @param host the host where the local emulator is running. If you want to access 'localhost'
+     *     from an Android Emulator use '10.0.2.2' instead.
+     * @param port the port where the local emulator is running.
+     */
+    public Builder(@NonNull String host, int port) {
+      this.host = host;
+      this.port = port;
+    }
+
+    @NonNull
+    public EmulatedServiceSettings build() {
+      return new EmulatedServiceSettings(this.host, this.port);
+    }
+  }
+
+  public final String host;
+  public final int port;
+
+  private EmulatedServiceSettings(@NonNull String host, int port) {
+    this.host = host;
+    this.port = port;
+  }
+}

firebase-common/src/main/java/com/google/firebase/emulators/EmulatorSettings.java

@@ -0,0 +1,103 @@
+// Copyright 2020 Google LLC
+//
+// 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 com.google.firebase.emulators;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import com.google.android.gms.common.annotation.KeepForSdk;
+import com.google.firebase.components.Preconditions;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+/**
+ * Settings that control which Firebase services should access a local emulator, rather than
+ * production.
+ *
+ * <p>TODO(samstern): Un-hide this once Firestore, Database, and Functions are implemented
+ *
+ * @see com.google.firebase.FirebaseApp#enableEmulators(EmulatorSettings)
+ * @hide
+ */
+@KeepForSdk
+public class EmulatorSettings {
+
+  public static final class Builder {
+
+    private final Map<FirebaseEmulators, EmulatedServiceSettings> settingsMap = new HashMap<>();
+
+    /** Constructs an empty builder. */
+    public Builder() {}
+
+    /**
+     * Specify the emulator settings for a single service.
+     *
+     * @param emulator the emulated service.
+     * @param settings the emulator settings.
+     * @return the builder, for chaining.
+     */
+    @NonNull
+    public Builder addEmulatedService(
+        @NonNull FirebaseEmulators emulator, @NonNull EmulatedServiceSettings settings) {
+      Preconditions.checkState(
+          !settingsMap.containsKey(emulator),
+          "Cannot call addEmulatedService twice for " + emulator.toString());
+      this.settingsMap.put(emulator, settings);
+      return this;
+    }
+
+    @NonNull
+    public EmulatorSettings build() {
+      return new EmulatorSettings(settingsMap);
+    }
+  }
+
+  private final AtomicBoolean accessed = new AtomicBoolean(false);
+  private final Map<FirebaseEmulators, EmulatedServiceSettings> settingsMap;
+
+  private EmulatorSettings(@NonNull Map<FirebaseEmulators, EmulatedServiceSettings> settingsMap) {
+    this.settingsMap = Collections.unmodifiableMap(settingsMap);
+  }
+
+  /**
+   * Determine if any Firebase SDK has already accessed the emulator settings. When true, attempting
+   * to change the settings should throw an error.
+   *
+   * @hide
+   */
+  public boolean isAccessed() {
+    return accessed.get();
+  }
+
+  /**
+   * Fetch the emulation settings for a single Firebase service. Once this method has been called
+   * {@link #isAccessed()} will return true.
+   *
+   * @hide
+   */
+  @Nullable
+  public EmulatedServiceSettings getServiceSettings(@NonNull FirebaseEmulators emulator) {
+    accessed.set(true);
+
+    if (settingsMap.containsKey(emulator)) {
+      return settingsMap.get(emulator);
+    }
+
+    return null;
+  }
+}