Add proper nullability annotations to firebase-common.

firebase-common/firebase-common.gradle

@@ -19,7 +19,6 @@ plugins {
 firebaseLibrary {
     testLab.enabled = true
     publishSources = true
-    staticAnalysis.disableKotlinInteropLint()
 }
 
 android {

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

@@ -38,7 +38,6 @@
 import com.google.android.gms.common.internal.Preconditions;
 import com.google.android.gms.common.util.PlatformVersion;
 import com.google.android.gms.common.util.ProcessUtils;
-import com.google.firebase.annotations.PublicApi;
 import com.google.firebase.components.Component;
 import com.google.firebase.components.ComponentDiscovery;
 import com.google.firebase.components.ComponentRegistrar;
@@ -85,12 +84,11 @@
  * Use of Firebase in processes other than the main process is not supported and will likely cause
  * problems related to resource contention.
  */
-@PublicApi
 public class FirebaseApp {
 
   private static final String LOG_TAG = "FirebaseApp";
 
-  public static final String DEFAULT_APP_NAME = "[DEFAULT]";
+  public static final @NonNull String DEFAULT_APP_NAME = "[DEFAULT]";
 
   private static final Object LOCK = new Object();
 
@@ -121,23 +119,20 @@ public class FirebaseApp {
 
   /** Returns the application {@link Context}. */
   @NonNull
-  @PublicApi
   public Context getApplicationContext() {
     checkNotDeleted();
     return applicationContext;
   }
 
   /** Returns the unique name of this app. */
   @NonNull
-  @PublicApi
   public String getName() {
     checkNotDeleted();
     return name;
   }
 
   /** Returns the specified {@link FirebaseOptions}. */
   @NonNull
-  @PublicApi
   public FirebaseOptions getOptions() {
     checkNotDeleted();
     return options;
@@ -162,8 +157,8 @@ public String toString() {
   }
 
   /** Returns a mutable list of all FirebaseApps. */
-  @PublicApi
-  public static List<FirebaseApp> getApps(Context context) {
+  @NonNull
+  public static List<FirebaseApp> getApps(@NonNull Context context) {
     synchronized (LOCK) {
       return new ArrayList<>(INSTANCES.values());
     }
@@ -175,7 +170,6 @@ public static List<FirebaseApp> getApps(Context context) {
    * @throws IllegalStateException if the default app was not initialized.
    */
   @NonNull
-  @PublicApi
   public static FirebaseApp getInstance() {
     synchronized (LOCK) {
       FirebaseApp defaultApp = INSTANCES.get(DEFAULT_APP_NAME);
@@ -199,7 +193,6 @@ public static FirebaseApp getInstance() {
    *     #initializeApp(Context, FirebaseOptions, String)}.
    */
   @NonNull
-  @PublicApi
   public static FirebaseApp getInstance(@NonNull String name) {
     synchronized (LOCK) {
       FirebaseApp firebaseApp = INSTANCES.get(normalize(name));
@@ -239,7 +232,6 @@ public static FirebaseApp getInstance(@NonNull String name) {
    *     keys are present in string resources. Returns null otherwise.
    */
   @Nullable
-  @PublicApi
   public static FirebaseApp initializeApp(@NonNull Context context) {
     synchronized (LOCK) {
       if (INSTANCES.containsKey(DEFAULT_APP_NAME)) {
@@ -267,7 +259,6 @@ public static FirebaseApp initializeApp(@NonNull Context context) {
    * initialization that way is the expected situation.
    */
   @NonNull
-  @PublicApi
   public static FirebaseApp initializeApp(
       @NonNull Context context, @NonNull FirebaseOptions options) {
     return initializeApp(context, options, DEFAULT_APP_NAME);
@@ -284,7 +275,6 @@ public static FirebaseApp initializeApp(
    * @return an instance of {@link FirebaseApp}
    */
   @NonNull
-  @PublicApi
   public static FirebaseApp initializeApp(
       @NonNull Context context, @NonNull FirebaseOptions options, @NonNull String name) {
     GlobalBackgroundStateListener.ensureBackgroundStateListenerRegistered(context);
@@ -319,7 +309,6 @@ public static FirebaseApp initializeApp(
    *
    * @hide
    */
-  @PublicApi
   public void delete() {
     boolean valueChanged = deleted.compareAndSet(false /* expected */, true);
     if (!valueChanged) {
@@ -348,7 +337,6 @@ public <T> T get(Class<T> anInterface) {
    * If set to true it indicates that Firebase should close database connections automatically when
    * the app is in the background. Disabled by default.
    */
-  @PublicApi
   public void setAutomaticResourceManagementEnabled(boolean enabled) {
     checkNotDeleted();
     boolean updated =

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

@@ -15,16 +15,13 @@
 package com.google.firebase;
 
 import androidx.annotation.NonNull;
-import com.google.firebase.annotations.PublicApi;
 
 /**
  * Exception thrown when a request to a Firebase service has failed due to a network error. Inspect
  * the device's network connectivity state or retry later to resolve.
  */
-@PublicApi
 public class FirebaseNetworkException extends FirebaseException {
 
-  @PublicApi
   public FirebaseNetworkException(@NonNull String detailMessage) {
     super(detailMessage);
   }

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

@@ -25,10 +25,8 @@
 import com.google.android.gms.common.internal.Objects;
 import com.google.android.gms.common.internal.Preconditions;
 import com.google.android.gms.common.internal.StringResourceValueReader;
-import com.google.firebase.annotations.PublicApi;
 
 /** Configurable Firebase options. */
-@PublicApi
 public final class FirebaseOptions {
 
   // TODO: deprecate and remove it once we can fetch these from Remote Config.
@@ -50,7 +48,6 @@ public final class FirebaseOptions {
   private final String projectId;
 
   /** Builder for constructing FirebaseOptions. */
-  @PublicApi
   public static final class Builder {
     private String apiKey;
     private String applicationId;
@@ -61,7 +58,6 @@ public static final class Builder {
     private String projectId;
 
     /** Constructs an empty builder. */
-    @PublicApi
     public Builder() {}
 
     /**
@@ -70,8 +66,7 @@ public Builder() {}
      * <p>The new builder is not backed by this objects values, that is changes made to the new
      * builder don't change the values of the origin object.
      */
-    @PublicApi
-    public Builder(FirebaseOptions options) {
+    public Builder(@NonNull FirebaseOptions options) {
       applicationId = options.applicationId;
       apiKey = options.apiKey;
       databaseUrl = options.databaseUrl;
@@ -81,51 +76,52 @@ public Builder(FirebaseOptions options) {
       projectId = options.projectId;
     }
 
-    @PublicApi
+    @NonNull
     public Builder setApiKey(@NonNull String apiKey) {
       this.apiKey = checkNotEmpty(apiKey, "ApiKey must be set.");
       return this;
     }
 
-    @PublicApi
+    @NonNull
     public Builder setApplicationId(@NonNull String applicationId) {
       this.applicationId = checkNotEmpty(applicationId, "ApplicationId must be set.");
       return this;
     }
 
-    @PublicApi
+    @NonNull
     public Builder setDatabaseUrl(@Nullable String databaseUrl) {
       this.databaseUrl = databaseUrl;
       return this;
     }
 
     /** @hide */
     // TODO: unhide once an API (AppInvite) starts reading it.
+    @NonNull
     @KeepForSdk
     public Builder setGaTrackingId(@Nullable String gaTrackingId) {
       this.gaTrackingId = gaTrackingId;
       return this;
     }
 
-    @PublicApi
+    @NonNull
     public Builder setGcmSenderId(@Nullable String gcmSenderId) {
       this.gcmSenderId = gcmSenderId;
       return this;
     }
 
-    @PublicApi
+    @NonNull
     public Builder setStorageBucket(@Nullable String storageBucket) {
       this.storageBucket = storageBucket;
       return this;
     }
 
-    @PublicApi
+    @NonNull
     public Builder setProjectId(@Nullable String projectId) {
       this.projectId = projectId;
       return this;
     }
 
-    @PublicApi
+    @NonNull
     public FirebaseOptions build() {
       return new FirebaseOptions(
           applicationId, apiKey, databaseUrl, gaTrackingId, gcmSenderId, storageBucket, projectId);
@@ -155,8 +151,8 @@ private FirebaseOptions(
    *
    * @return The populated options or null if applicationId is missing from resources.
    */
-  @PublicApi
-  public static FirebaseOptions fromResource(Context context) {
+  @Nullable
+  public static FirebaseOptions fromResource(@NonNull Context context) {
     StringResourceValueReader reader = new StringResourceValueReader(context);
     String applicationId = reader.getString(APP_ID_RESOURCE_NAME);
     if (TextUtils.isEmpty(applicationId)) {
@@ -176,19 +172,19 @@ public static FirebaseOptions fromResource(Context context) {
    * API key used for authenticating requests from your app, e.g.
    * AIzaSyDdVgKwhZl0sTTTLZ7iTmt1r3N2cJLnaDk, used to identify your app to Google servers.
    */
-  @PublicApi
+  @NonNull
   public String getApiKey() {
     return apiKey;
   }
 
   /** The Google App ID that is used to uniquely identify an instance of an app. */
-  @PublicApi
+  @NonNull
   public String getApplicationId() {
     return applicationId;
   }
 
   /** The database root URL, e.g. http://abc-xyz-123.firebaseio.com. */
-  @PublicApi
+  @Nullable
   public String getDatabaseUrl() {
     return databaseUrl;
   }
@@ -199,6 +195,7 @@ public String getDatabaseUrl() {
    * @hide
    */
   // TODO: unhide once an API (AppInvite) starts reading it.
+  @Nullable
   @KeepForSdk
   public String getGaTrackingId() {
     return gaTrackingId;
@@ -208,19 +205,19 @@ public String getGaTrackingId() {
    * The Project Number from the Google Developer's console, for example 012345678901, used to
    * configure Google Cloud Messaging.
    */
-  @PublicApi
+  @Nullable
   public String getGcmSenderId() {
     return gcmSenderId;
   }
 
   /** The Google Cloud Storage bucket name, e.g. abc-xyz-123.storage.firebase.com. */
-  @PublicApi
+  @Nullable
   public String getStorageBucket() {
     return storageBucket;
   }
 
   /** The Google Cloud project ID, e.g. my-project-1234 */
-  @PublicApi
+  @Nullable
   public String getProjectId() {
     return projectId;
   }

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

@@ -14,17 +14,15 @@
 
 package com.google.firebase;
 
-import com.google.firebase.annotations.PublicApi;
+import androidx.annotation.NonNull;
 
 /**
  * Exception thrown when a request to a Firebase service has been blocked due to having received too
  * many consecutive requests from the same device. Retry the request later to resolve.
  */
-@PublicApi
 public class FirebaseTooManyRequestsException extends FirebaseException {
 
-  @PublicApi
-  public FirebaseTooManyRequestsException(String message) {
+  public FirebaseTooManyRequestsException(@NonNull String message) {
     super(message);
   }
 }

firebase-common/src/main/java/com/google/firebase/annotations/package-info.java

@@ -13,4 +13,4 @@
 // limitations under the License.
 
 /** @hide */
-package com.google.firebase.annotations;
+package com.google.firebase.annotations;

firebase-common/src/main/java/com/google/firebase/internal/package-info.java

@@ -0,0 +1,16 @@
+// Copyright 2019 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.
+
+/** @hide */
+package com.google.firebase.internal;