[Experimental] Use dagger in functions.

Author: vkryachko

firebase-functions/firebase-functions.gradle

@@ -14,6 +14,7 @@
 
 plugins {
     id 'firebase-library'
+    id 'firebase-vendor'
 }
 
 firebaseLibrary {
@@ -68,6 +69,12 @@ dependencies {
 
     implementation 'com.squareup.okhttp3:okhttp:3.12.1'
 
+    implementation 'javax.inject:javax.inject:1'
+    vendor ('com.google.dagger:dagger:2.43.2') {
+        exclude group: "javax.inject", module: "javax.inject"
+    }
+    annotationProcessor 'com.google.dagger:dagger-compiler:2.43.2'
+
     annotationProcessor 'com.google.auto.value:auto-value:1.6.2'
 
     javadocClasspath 'com.google.code.findbugs:jsr305:3.0.2'

firebase-functions/src/androidTest/java/com/google/firebase/functions/CallTest.java

@@ -22,7 +22,6 @@
 
 import androidx.test.InstrumentationRegistry;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
-
 import com.google.android.gms.tasks.Task;
 import com.google.android.gms.tasks.Tasks;
 import com.google.firebase.FirebaseApp;
@@ -86,7 +85,6 @@ public void testToken() throws InterruptedException, ExecutionException {
     // Override the normal token provider to simulate FirebaseAuth being logged in.
     FirebaseFunctions functions =
         new FirebaseFunctions(
-            app,
             app.getApplicationContext(),
             app.getOptions().getProjectId(),
             "us-central1",
@@ -108,7 +106,6 @@ public void testInstanceId() throws InterruptedException, ExecutionException {
     // Override the normal token provider to simulate FirebaseAuth being logged in.
     FirebaseFunctions functions =
         new FirebaseFunctions(
-            app,
             app.getApplicationContext(),
             app.getOptions().getProjectId(),
             "us-central1",
@@ -130,7 +127,6 @@ public void testAppCheck() throws InterruptedException, ExecutionException {
     // Override the normal token provider to simulate FirebaseAuth being logged in.
     FirebaseFunctions functions =
         new FirebaseFunctions(
-            app,
             app.getApplicationContext(),
             app.getOptions().getProjectId(),
             "us-central1",

firebase-functions/src/main/java/com/google/firebase/functions/FirebaseContextProvider.java

@@ -26,8 +26,11 @@
 import com.google.firebase.internal.api.FirebaseNoSignedInUserException;
 import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicReference;
+import javax.inject.Inject;
+import javax.inject.Singleton;
 
 /** A ContextProvider that uses FirebaseAuth to get the token. */
+@Singleton
 class FirebaseContextProvider implements ContextProvider {
   private final String TAG = "FirebaseContextProvider";
 
@@ -37,6 +40,7 @@ class FirebaseContextProvider implements ContextProvider {
       new AtomicReference<>();
   private final Executor executor;
 
+  @Inject
   FirebaseContextProvider(
       Provider<InternalAuthProvider> tokenProvider,
       Provider<FirebaseInstanceIdInternal> instanceId,

firebase-functions/src/main/java/com/google/firebase/functions/FirebaseFunctions.java

@@ -30,13 +30,16 @@
 import com.google.firebase.annotations.concurrent.Lightweight;
 import com.google.firebase.emulators.EmulatedServiceSettings;
 import com.google.firebase.functions.FirebaseFunctionsException.Code;
+import dagger.assisted.Assisted;
+import dagger.assisted.AssistedInject;
 import java.io.IOException;
 import java.io.InterruptedIOException;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.Executor;
+import javax.inject.Named;
 import okhttp3.Call;
 import okhttp3.Callback;
 import okhttp3.MediaType;
@@ -59,9 +62,6 @@ public class FirebaseFunctions {
    */
   private static boolean providerInstallStarted = false;
 
-  // The FirebaseApp instance
-  private final FirebaseApp app;
-
   // The network client to use for HTTPS requests.
   private final OkHttpClient client;
 
@@ -88,14 +88,13 @@ public class FirebaseFunctions {
   // Emulator settings
   @Nullable private EmulatedServiceSettings emulatorSettings;
 
+  @AssistedInject
   FirebaseFunctions(
-      FirebaseApp app,
       Context context,
-      String projectId,
-      String regionOrCustomDomain,
+      @Named("projectId") String projectId,
+      @Assisted String regionOrCustomDomain,
       ContextProvider contextProvider,
       @Lightweight Executor executor) {
-    this.app = app;
     this.executor = executor;
     this.client = new OkHttpClient();
     this.serializer = new Serializer();

firebase-functions/src/main/java/com/google/firebase/functions/FirebaseFunctionsFactory.java

@@ -0,0 +1,9 @@
+package com.google.firebase.functions;
+
+import dagger.assisted.Assisted;
+import dagger.assisted.AssistedFactory;
+
+@AssistedFactory
+interface FirebaseFunctionsFactory {
+  FirebaseFunctions create(@Assisted String regionOrCustomDomain);
+}

firebase-functions/src/main/java/com/google/firebase/functions/FunctionsComponent.java

@@ -0,0 +1,44 @@
+package com.google.firebase.functions;
+
+import android.content.Context;
+import com.google.firebase.FirebaseOptions;
+import com.google.firebase.annotations.concurrent.Lightweight;
+import com.google.firebase.appcheck.interop.InternalAppCheckTokenProvider;
+import com.google.firebase.auth.internal.InternalAuthProvider;
+import com.google.firebase.iid.internal.FirebaseInstanceIdInternal;
+import com.google.firebase.inject.Deferred;
+import com.google.firebase.inject.Provider;
+import dagger.BindsInstance;
+import dagger.Component;
+import java.util.concurrent.Executor;
+import javax.inject.Singleton;
+
+/** @hide */
+@Component(modules = MainModule.class)
+@Singleton
+interface FunctionsComponent {
+  FunctionsMultiResourceComponent getMultiResourceComponent();
+
+  @Component.Builder
+  interface Builder {
+    @BindsInstance
+    Builder setApplicationContext(Context applicationContext);
+
+    @BindsInstance
+    Builder setFirebaseOptions(FirebaseOptions options);
+
+    @BindsInstance
+    Builder setLiteExecutor(@Lightweight Executor executor);
+
+    @BindsInstance
+    Builder setAuth(Provider<InternalAuthProvider> auth);
+
+    @BindsInstance
+    Builder setIid(Provider<FirebaseInstanceIdInternal> iid);
+
+    @BindsInstance
+    Builder setAppCheck(Deferred<InternalAppCheckTokenProvider> appCheck);
+
+    FunctionsComponent build();
+  }
+}

firebase-functions/src/main/java/com/google/firebase/functions/FunctionsMultiResourceComponent.java

@@ -14,15 +14,14 @@
 
 package com.google.firebase.functions;
 
-import android.content.Context;
 import androidx.annotation.GuardedBy;
-import com.google.firebase.FirebaseApp;
-import com.google.firebase.annotations.concurrent.Lightweight;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.concurrent.Executor;
+import javax.inject.Inject;
+import javax.inject.Singleton;
 
 /** Multi-resource container for Functions. */
+@Singleton
 class FunctionsMultiResourceComponent {
   /**
    * A static map from instance key to FirebaseFunctions instances. Instance keys region names.
@@ -32,32 +31,20 @@ class FunctionsMultiResourceComponent {
   @GuardedBy("this")
   private final Map<String, FirebaseFunctions> instances = new HashMap<>();
 
-  private final Context applicationContext;
-  private final ContextProvider contextProvider;
-  private final FirebaseApp app;
-  private final Executor executor;
+  private final FirebaseFunctionsFactory functionsFactory;
 
-  FunctionsMultiResourceComponent(
-      Context applicationContext,
-      ContextProvider contextProvider,
-      FirebaseApp app,
-      @Lightweight Executor executor) {
-    this.applicationContext = applicationContext;
-    this.contextProvider = contextProvider;
-    this.app = app;
-    this.executor = executor;
+  @Inject
+  FunctionsMultiResourceComponent(FirebaseFunctionsFactory functionsFactory) {
+    this.functionsFactory = functionsFactory;
   }
 
   synchronized FirebaseFunctions get(String regionOrCustomDomain) {
     FirebaseFunctions functions = instances.get(regionOrCustomDomain);
-    String projectId = app.getOptions().getProjectId();
-
-    if (functions == null) {
-      functions =
-          new FirebaseFunctions(
-              app, applicationContext, projectId, regionOrCustomDomain, contextProvider, executor);
-      instances.put(regionOrCustomDomain, functions);
+    if (functions != null) {
+      return functions;
     }
+    functions = functionsFactory.create(regionOrCustomDomain);
+    instances.put(regionOrCustomDomain, functions);
     return functions;
   }
 }

firebase-functions/src/main/java/com/google/firebase/functions/FunctionsRegistrar.java

@@ -16,7 +16,7 @@
 
 import android.content.Context;
 import androidx.annotation.Keep;
-import com.google.firebase.FirebaseApp;
+import com.google.firebase.FirebaseOptions;
 import com.google.firebase.annotations.concurrent.Lightweight;
 import com.google.firebase.appcheck.interop.InternalAppCheckTokenProvider;
 import com.google.firebase.auth.internal.InternalAuthProvider;
@@ -43,30 +43,25 @@ public class FunctionsRegistrar implements ComponentRegistrar {
   public List<Component<?>> getComponents() {
     Qualified<Executor> liteExecutor = Qualified.qualified(Lightweight.class, Executor.class);
     return Arrays.asList(
-        Component.builder(ContextProvider.class)
-            .add(Dependency.optionalProvider(InternalAuthProvider.class))
-            .add(Dependency.requiredProvider(FirebaseInstanceIdInternal.class))
-            .add(Dependency.deferred(InternalAppCheckTokenProvider.class))
-            .factory(
-                c ->
-                    new FirebaseContextProvider(
-                        c.getProvider(InternalAuthProvider.class),
-                        c.getProvider(FirebaseInstanceIdInternal.class),
-                        c.getDeferred(InternalAppCheckTokenProvider.class),
-                        c.get(liteExecutor)))
-            .build(),
         Component.builder(FunctionsMultiResourceComponent.class)
             .name(LIBRARY_NAME)
             .add(Dependency.required(Context.class))
-            .add(Dependency.required(ContextProvider.class))
-            .add(Dependency.required(FirebaseApp.class))
+            .add(Dependency.required(FirebaseOptions.class))
+            .add(Dependency.required(liteExecutor))
+            .add(Dependency.optionalProvider(InternalAuthProvider.class))
+            .add(Dependency.requiredProvider(FirebaseInstanceIdInternal.class))
+            .add(Dependency.deferred(InternalAppCheckTokenProvider.class))
             .factory(
                 c ->
-                    new FunctionsMultiResourceComponent(
-                        c.get(Context.class),
-                        c.get(ContextProvider.class),
-                        c.get(FirebaseApp.class),
-                        c.get(liteExecutor)))
+                    DaggerFunctionsComponent.builder()
+                        .setApplicationContext(c.get(Context.class))
+                        .setFirebaseOptions(c.get(FirebaseOptions.class))
+                        .setLiteExecutor(c.get(liteExecutor))
+                        .setAuth(c.getProvider(InternalAuthProvider.class))
+                        .setIid(c.getProvider(FirebaseInstanceIdInternal.class))
+                        .setAppCheck(c.getDeferred(InternalAppCheckTokenProvider.class))
+                        .build()
+                        .getMultiResourceComponent())
             .build(),
         LibraryVersionComponent.create(LIBRARY_NAME, BuildConfig.VERSION_NAME));
   }

firebase-functions/src/main/java/com/google/firebase/functions/MainModule.java

@@ -0,0 +1,19 @@
+package com.google.firebase.functions;
+
+import com.google.firebase.FirebaseOptions;
+import dagger.Binds;
+import dagger.Module;
+import dagger.Provides;
+import javax.inject.Named;
+
+@Module
+interface MainModule {
+  @Provides
+  @Named("projectId")
+  static String bindProjectId(FirebaseOptions options) {
+    return options.getProjectId();
+  }
+
+  @Binds
+  ContextProvider contextProvider(FirebaseContextProvider provider);
+}

firebase-functions/src/main/java/com/google/firebase/functions/Serializer.java

@@ -38,7 +38,7 @@ class Serializer {
 
   private final DateFormat dateFormat;
 
-  public Serializer() {
+  Serializer() {
     // Encode Dates as UTC ISO 8601 strings.
     dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.US);
     dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));