Change SendEmailService to an instance field.

This allows us to inject it with Dagger and avoid using InjectRule to set it
in unit tests.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=217571475

java/google/registry/reporting/icann/IcannReportingModule.java

@@ -25,7 +25,6 @@ import dagger.Provides;
 import google.registry.bigquery.BigqueryConnection;
 import google.registry.request.HttpException.BadRequestException;
 import google.registry.request.Parameter;
-import google.registry.util.SendEmailService;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.util.Optional;
@@ -115,11 +114,6 @@ public final class IcannReportingModule {
     }
   }
 
-  @Provides
-  static SendEmailService provideSendEmailService() {
-    return new SendEmailService();
-  }
-
   /** Dagger qualifier for the subdirectory we stage to/upload from. */
   @Qualifier
   @Documented

java/google/registry/ui/server/registrar/SendEmailUtils.java

@@ -21,7 +21,6 @@ import com.google.common.base.Joiner;
 import com.google.common.collect.Streams;
 import com.google.common.flogger.FluentLogger;
 import google.registry.config.RegistryConfig.Config;
-import google.registry.util.NonFinalForTesting;
 import google.registry.util.SendEmailService;
 import java.util.List;
 import java.util.Objects;
@@ -39,18 +38,18 @@ public class SendEmailUtils {
 
   private final String gSuiteOutgoingEmailAddress;
   private final String gSuiteOutoingEmailDisplayName;
+  private final SendEmailService emailService;
 
   @Inject
   public SendEmailUtils(
       @Config("gSuiteOutgoingEmailAddress") String gSuiteOutgoingEmailAddress,
-      @Config("gSuiteOutoingEmailDisplayName") String gSuiteOutoingEmailDisplayName) {
+      @Config("gSuiteOutoingEmailDisplayName") String gSuiteOutoingEmailDisplayName,
+      SendEmailService emailService) {
     this.gSuiteOutgoingEmailAddress = gSuiteOutgoingEmailAddress;
     this.gSuiteOutoingEmailDisplayName = gSuiteOutoingEmailDisplayName;
+    this.emailService = emailService;
   }
 
-  @NonFinalForTesting
-  private static SendEmailService emailService = new SendEmailService();
-
   /**
    * Sends an email from Nomulus to the specified recipient(s). Returns true iff sending was
    * successful.

java/google/registry/util/SendEmailService.java

@@ -15,6 +15,8 @@
 package google.registry.util;
 
 import java.util.Properties;
+import javax.inject.Inject;
+import javax.inject.Singleton;
 import javax.mail.Message;
 import javax.mail.MessagingException;
 import javax.mail.Session;
@@ -22,8 +24,12 @@ import javax.mail.Transport;
 import javax.mail.internet.MimeMessage;
 
 /** Wrapper around javax.mail's Transport.send that can be mocked for testing purposes. */
+@Singleton
 public class SendEmailService {
 
+  @Inject
+  SendEmailService() {};
+
   /** Returns a new MimeMessage using default App Engine transport settings. */
   public Message createMessage() {
     return new MimeMessage(Session.getDefaultInstance(new Properties(), null));

javatests/google/registry/ui/server/registrar/RegistrarSettingsActionTestCase.java

@@ -91,14 +91,14 @@ public class RegistrarSettingsActionTestCase {
     action.registrarChangesNotificationEmailAddresses = ImmutableList.of(
         "notification@test.example", "notification2@test.example");
     action.sendEmailUtils =
-        new SendEmailUtils(getGSuiteOutgoingEmailAddress(), getGSuiteOutgoingEmailDisplayName());
+        new SendEmailUtils(
+            getGSuiteOutgoingEmailAddress(), getGSuiteOutgoingEmailDisplayName(), emailService);
     action.registryEnvironment = RegistryEnvironment.get();
     action.authResult =
         AuthResult.create(
             AuthLevel.USER,
             UserAuthInfo.create(new User("user@email.com", "email.com", "12345"), false));
     inject.setStaticField(Ofy.class, "clock", clock);
-    inject.setStaticField(SendEmailUtils.class, "emailService", emailService);
     message = new MimeMessage(Session.getDefaultInstance(new Properties(), null));
     when(emailService.createMessage()).thenReturn(message);
     when(req.getMethod()).thenReturn("POST");

javatests/google/registry/ui/server/registrar/SendEmailUtilsTest.java

@@ -25,7 +25,6 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import com.google.common.collect.ImmutableList;
-import google.registry.testing.InjectRule;
 import google.registry.util.SendEmailService;
 import java.util.Properties;
 import javax.mail.Message;
@@ -35,7 +34,6 @@ import javax.mail.Session;
 import javax.mail.internet.InternetAddress;
 import javax.mail.internet.MimeMessage;
 import org.junit.Before;
-import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -44,9 +42,6 @@ import org.junit.runners.JUnit4;
 @RunWith(JUnit4.class)
 public class SendEmailUtilsTest {
 
-  @Rule
-  public final InjectRule inject = new InjectRule();
-
   private final SendEmailService emailService = mock(SendEmailService.class);
 
   private Message message;
@@ -54,11 +49,11 @@ public class SendEmailUtilsTest {
 
   @Before
   public void init() {
-    inject.setStaticField(SendEmailUtils.class, "emailService", emailService);
     message = new MimeMessage(Session.getDefaultInstance(new Properties(), null));
     when(emailService.createMessage()).thenReturn(message);
     sendEmailUtils =
-        new SendEmailUtils(getGSuiteOutgoingEmailAddress(), getGSuiteOutgoingEmailDisplayName());
+        new SendEmailUtils(
+            getGSuiteOutgoingEmailAddress(), getGSuiteOutgoingEmailDisplayName(), emailService);
   }
 
   @Test