Allow to create FirebaseCredentials from GoogleCredentials

build.gradle

@@ -168,7 +168,7 @@ subprojects {
                     "com.google.http-client:google-http-client:1.29.0",
                     "com.google.http-client:google-http-client-jackson2:1.29.0",
 
-                    "com.google.api-client:google-api-client:1.25.0",
+                    "com.google.api-client:google-api-client:1.30.9",
 
                     "org.apache.httpcomponents:httpclient:4.5.5",
 

client-js/package.json

@@ -1,6 +1,6 @@
 {
   "name": "spine-web",
-  "version": "1.5.0",
+  "version": "1.5.2",
   "license": "Apache-2.0",
   "description": "A JS client for interacting with Spine applications.",
   "homepage": "https://spine.io",

firebase-web/src/main/java/io/spine/web/firebase/FirebaseClientFactory.java

@@ -21,7 +21,6 @@
 package io.spine.web.firebase;
 
 import com.google.api.client.extensions.appengine.http.UrlFetchTransport;
-import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
 import com.google.api.client.http.HttpRequestFactory;
 import com.google.api.client.http.HttpTransport;
 import com.google.api.client.http.apache.ApacheHttpTransport;
@@ -149,8 +148,7 @@ private static FirebaseClient createAuthorized(HttpTransport httpTransport,
                                                    FirebaseDatabase database,
                                                    FirebaseCredentials credentials,
                                                    Supplier<BackOff> backOff) {
-        GoogleCredential googleCredentials = credentials.credentials();
-        HttpRequestFactory requestFactory = httpTransport.createRequestFactory(googleCredentials);
+        HttpRequestFactory requestFactory = httpTransport.createRequestFactory(credentials);
         return RemoteDatabaseClient
                 .newBuilder()
                 .setDatabase(database)

firebase-web/src/main/java/io/spine/web/firebase/FirebaseCredentials.java

@@ -21,25 +21,33 @@
 package io.spine.web.firebase;
 
 import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
+import com.google.api.client.http.HttpRequest;
+import com.google.api.client.http.HttpRequestInitializer;
+import com.google.auth.http.HttpCredentialsAdapter;
+import com.google.auth.oauth2.GoogleCredentials;
+import com.google.common.annotations.VisibleForTesting;
+import io.spine.annotation.Internal;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
-import javax.annotation.Nullable;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Collection;
 
 import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
 import static io.spine.util.Exceptions.newIllegalArgumentException;
 import static java.util.Arrays.asList;
 
 /**
  * A Firebase Database credentials.
  *
- * <p>The underlying Google OAuth 2.0 service can be used as an authentication facility for the
- * requests to Firebase REST API.
+ * <p>This type can be used as an authentication facility for the requests to Firebase REST API.
  *
  * <p>See <a href="https://firebase.google.com/docs/database/rest/auth">Firebase REST docs</a>.
  */
-public final class FirebaseCredentials {
+@SuppressWarnings("deprecation")
+// Use deprecated `GoogleCredential` to retain backward compatibility.
+public final class FirebaseCredentials implements HttpRequestInitializer {
 
     private static final String AUTH_DATABASE = "https://www.googleapis.com/auth/firebase.database";
     private static final String AUTH_USER_EMAIL = "https://www.googleapis.com/auth/userinfo.email";
@@ -49,14 +57,33 @@ public final class FirebaseCredentials {
      */
     private static final Collection<String> AUTH_SCOPES = asList(AUTH_DATABASE, AUTH_USER_EMAIL);
 
-    private final GoogleCredential credentials;
+    /**
+     * The credential used for authentication.
+     *
+     * <p>Either this field or {@link #oldStyleCredential} will always be {@code null}.
+     */
+    private final @Nullable GoogleCredentials credentials;
+
+    /**
+     * The credential used for authentication.
+     *
+     * <p>Either this field or {@link #credentials} will always be {@code null}.
+     */
+    private final @Nullable GoogleCredential oldStyleCredential;
 
     private FirebaseCredentials() {
         this.credentials = null;
+        this.oldStyleCredential = null;
     }
 
-    private FirebaseCredentials(GoogleCredential credentials) {
+    private FirebaseCredentials(GoogleCredentials credentials) {
         this.credentials = credentials;
+        this.oldStyleCredential = null;
+    }
+
+    private FirebaseCredentials(GoogleCredential credential) {
+        this.credentials = null;
+        this.oldStyleCredential = credential;
     }
 
     /**
@@ -69,16 +96,32 @@ public static FirebaseCredentials empty() {
     }
 
     /**
-     * Creates a new {@code FirebaseCredentials} from the given {@link GoogleCredential}.
+     * Creates a new {@code FirebaseCredentials} from the given {@link GoogleCredentials}.
      *
-     * <p>The method sets scopes required for Firebase.
+     * <p>This method sets scopes required to use the Firebase database.
      *
-     * <p>The method is useful to create credentials from the
-     * {@linkplain GoogleCredential#getApplicationDefault() application default credentials}.
+     * <p>This method is useful to create credentials from the
+     * {@linkplain GoogleCredentials#getApplicationDefault() application default credentials}.
      *
-     * @param credentials the credentials to create from
+     * @param credentials
+     *         the credentials to create from
      * @return a new instance of {@code FirebaseCredentials}
      */
+    public static FirebaseCredentials fromGoogleCredentials(GoogleCredentials credentials) {
+        checkNotNull(credentials);
+        GoogleCredentials scopedCredential = credentials.createScoped(AUTH_SCOPES);
+        return new FirebaseCredentials(scopedCredential);
+    }
+
+    /**
+     * Creates a new {@code FirebaseCredentials} from the given {@link GoogleCredentials}.
+     *
+     * <p>This method sets scopes required to use the Firebase database.
+     *
+     * @deprecated please use {@link #fromGoogleCredentials(GoogleCredentials)} or any other
+     *             alternative instead
+     */
+    @Deprecated
     public static FirebaseCredentials fromGoogleCredentials(GoogleCredential credentials) {
         checkNotNull(credentials);
         GoogleCredential scopedCredential = credentials.createScoped(AUTH_SCOPES);
@@ -98,37 +141,50 @@ public static FirebaseCredentials fromGoogleCredentials(GoogleCredential credent
      * @return a new instance of {@code FirebaseCredentials}
      * @throws java.lang.IllegalArgumentException
      *         in case there are problems with parsing the given stream into
-     *         {@link GoogleCredential}
+     *         {@link GoogleCredentials}
      */
     public static FirebaseCredentials fromStream(InputStream credentialStream) {
         checkNotNull(credentialStream);
-        GoogleCredential credentials = parseCredentials(credentialStream);
+        GoogleCredentials credentials = parseCredentials(credentialStream);
         return fromGoogleCredentials(credentials);
     }
 
     /**
-     * Checks if the instance of the {@code FirebaseCredentials} is empty.
+     * Authenticates a given {@link HttpRequest} with the wrapped Google credentials instance.
      *
-     * @return {@code true} if {@code FirebaseCredentials} are empty and {@code false} otherwise
+     * @throws IllegalStateException
+     *         if this instance of {@code FirebaseCredentials} is {@linkplain #isEmpty() empty}
      */
-    public boolean isEmpty() {
-        return credentials == null;
+    @Internal
+    @Override
+    public void initialize(HttpRequest request) throws IOException {
+        checkState(!isEmpty(),
+                   "An empty credentials instance cannot serve as HTTP request initializer.");
+        if (isOldStyle()) {
+            oldStyleCredential.initialize(request);
+        } else {
+            HttpRequestInitializer adapter = new HttpCredentialsAdapter(credentials);
+            adapter.initialize(request);
+        }
     }
 
     /**
-     * Returns the underlying Google credentials.
+     * Checks if the instance of the {@code FirebaseCredentials} is empty.
      *
-     * @return the underlying credentials or {@code null} if the credentials are
-     *         {@linkplain #isEmpty() empty}
+     * @return {@code true} if {@code FirebaseCredentials} are empty and {@code false} otherwise
      */
-    @Nullable
-    GoogleCredential credentials() {
-        return credentials;
+    public boolean isEmpty() {
+        return credentials == null && oldStyleCredential == null;
+    }
+
+    @VisibleForTesting
+    boolean isOldStyle() {
+        return oldStyleCredential != null;
     }
 
-    private static GoogleCredential parseCredentials(InputStream credentialStream) {
+    private static GoogleCredentials parseCredentials(InputStream credentialStream) {
         try {
-            GoogleCredential credentials = GoogleCredential.fromStream(credentialStream);
+            GoogleCredentials credentials = GoogleCredentials.fromStream(credentialStream);
             return credentials;
         } catch (IOException e) {
             throw newIllegalArgumentException(

firebase-web/src/test/java/io/spine/web/firebase/FirebaseClientFactoryTest.java

@@ -20,7 +20,6 @@
 
 package io.spine.web.firebase;
 
-import com.google.api.client.googleapis.testing.auth.oauth2.MockGoogleCredential;
 import com.google.auth.oauth2.AccessToken;
 import com.google.auth.oauth2.GoogleCredentials;
 import com.google.common.testing.NullPointerTester;
@@ -39,16 +38,12 @@
 import java.util.Date;
 
 import static com.google.common.truth.Truth.assertThat;
-import static io.spine.web.firebase.FirebaseCredentials.fromGoogleCredentials;
 import static org.mockito.Mockito.mock;
 
-@DisplayName("FirebaseClientFactory should")
+@DisplayName("`FirebaseClientFactory` should")
 class FirebaseClientFactoryTest extends UtilityClassTest<FirebaseClientFactory> {
 
-    private static final MockGoogleCredential GOOGLE_CREDENTIALS =
-            new MockGoogleCredential.Builder().build();
-    private static final FirebaseCredentials CREDENTIALS =
-            fromGoogleCredentials(GOOGLE_CREDENTIALS);
+    private static final FirebaseCredentials CREDENTIALS = FirebaseCredentials.empty();
     private static final String FIREBASE_APP_NAME = FirebaseClientFactoryTest.class.getSimpleName();
     private FirebaseDatabase database = mock(FirebaseDatabase.class);
 

firebase-web/src/test/java/io/spine/web/firebase/FirebaseCredentialsTest.java

@@ -20,18 +20,22 @@
 
 package io.spine.web.firebase;
 
+import com.google.api.client.googleapis.testing.auth.oauth2.MockGoogleCredential;
+import com.google.auth.oauth2.GoogleCredentials;
 import com.google.common.testing.NullPointerTester;
 import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 
 import java.io.ByteArrayInputStream;
 import java.io.InputStream;
 
+import static com.google.common.truth.Truth.assertThat;
 import static io.spine.testing.DisplayNames.NOT_ACCEPT_NULLS;
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
-@DisplayName("FirebaseCredentials should")
+@DisplayName("`FirebaseCredentials` should")
 class FirebaseCredentialsTest {
 
     @Test
@@ -40,9 +44,43 @@ void passNullToleranceCheck() {
         new NullPointerTester().testAllPublicStaticMethods(FirebaseCredentials.class);
     }
 
+    @Nested
+    @DisplayName("be created")
+    class BeCreated {
+
+        @Test
+        @DisplayName("without credentials")
+        void empty() {
+            FirebaseCredentials credentials = FirebaseCredentials.empty();
+            assertThat(credentials.isEmpty()).isTrue();
+        }
+
+        @Test
+        @DisplayName("from `GoogleCredentials` instance")
+        void fromGoogleCredentials() {
+            GoogleCredentials googleCredentials = GoogleCredentials.newBuilder()
+                                                                   .build();
+            FirebaseCredentials credentials =
+                    FirebaseCredentials.fromGoogleCredentials(googleCredentials);
+            assertThat(credentials.isEmpty()).isFalse();
+            assertThat(credentials.isOldStyle()).isFalse();
+        }
+
+        @SuppressWarnings("deprecation") // This test checks the deprecated method.
+        @Test
+        @DisplayName("from `GoogleCredential` instance")
+        void fromOldStyleCredentials() {
+            MockGoogleCredential googleCredential = new MockGoogleCredential.Builder().build();
+            FirebaseCredentials credentials =
+                    FirebaseCredentials.fromGoogleCredentials(googleCredential);
+            assertThat(credentials.isEmpty()).isFalse();
+            assertThat(credentials.isOldStyle()).isTrue();
+        }
+    }
+
     @SuppressWarnings({"CheckReturnValue", "ResultOfMethodCallIgnored"})
     @Test
-    @DisplayName("throw IAE when created from invalid data")
+    @DisplayName("throw `IAE` when created from invalid data")
     void throwOnInvalidData() {
         String invalidCredentials = "invalid_credentials";
         InputStream stream = toInputStream(invalidCredentials);

integration-tests/js-tests/package.json

@@ -1,6 +1,6 @@
 {
   "name": "client-js-tests",
-  "version": "1.5.0",
+  "version": "1.5.2",
   "license": "Apache-2.0",
   "description": "Tests of a `spine-web` JS library against the Spine-based application.",
   "scripts": {

integration-tests/test-app/src/main/java/io/spine/web/test/given/Application.java

@@ -20,7 +20,6 @@
 
 package io.spine.web.test.given;
 
-import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
 import com.google.auth.oauth2.GoogleCredentials;
 import com.google.firebase.FirebaseApp;
 import com.google.firebase.FirebaseOptions;
@@ -95,12 +94,9 @@ static Application create(BoundedContext boundedContext) {
     private static FirebaseClient buildClient() {
         Resource googleCredentialsFile = Resource.file("spine-dev.json");
 
-        // Same credentials but represented with different Java objects.
         GoogleCredentials credentials;
-        GoogleCredential credential;
         try {
             credentials = GoogleCredentials.fromStream(googleCredentialsFile.open());
-            credential = GoogleCredential.fromStream(googleCredentialsFile.open());
         } catch (IOException e) {
             throw new IllegalStateException(e);
         }
@@ -112,7 +108,7 @@ private static FirebaseClient buildClient() {
         FirebaseApp.initializeApp(options);
 
         FirebaseDatabase database = FirebaseDatabase.getInstance();
-        FirebaseCredentials firebaseCredentials = fromGoogleCredentials(credential);
+        FirebaseCredentials firebaseCredentials = fromGoogleCredentials(credentials);
         FirebaseClient firebaseClient = remoteClient(database, firebaseCredentials);
         return new TidyClient(firebaseClient);
     }