Use a fake EmailSender in tests

Instead of disabling email entirely, allow sent emails to be buffered
into a fake sender that can be inspected later.

To facilitate making assertions over emails, make EmailHeader
implementations more immutable, and implement
equals/hashCode/toString.

Change-Id: I483ea9f9216de1c5eb3635fa56f7ad9318c2bebf

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/GerritServer.java

@@ -28,6 +28,7 @@ import com.google.gerrit.server.git.SubmoduleOp;
 import com.google.gerrit.server.index.ChangeSchemas;
 import com.google.gerrit.server.ssh.NoSshModule;
 import com.google.gerrit.server.util.SocketUtil;
+import com.google.gerrit.testutil.FakeEmailSender;
 import com.google.gerrit.testutil.TempFileUtil;
 import com.google.inject.Injector;
 import com.google.inject.Key;
@@ -115,6 +116,7 @@ public class GerritServer {
         }
       }
     });
+    daemon.setEmailModuleForTesting(new FakeEmailSender.Module());
 
     final File site;
     ExecutorService daemonService = null;

gerrit-pgm/src/main/java/com/google/gerrit/pgm/Daemon.java

@@ -152,6 +152,7 @@ public class Daemon extends SiteProgram {
   private Path runFile;
   private boolean test;
   private AbstractModule luceneModule;
+  private Module emailModule;
 
   private Runnable serverStarted;
 
@@ -261,6 +262,11 @@ public class Daemon extends SiteProgram {
     headless = true;
   }
 
+  @VisibleForTesting
+  public void setEmailModuleForTesting(Module module) {
+    emailModule = module;
+  }
+
   @VisibleForTesting
   public void setLuceneModule(LuceneIndexModule m) {
     luceneModule = m;
@@ -322,7 +328,11 @@ public class Daemon extends SiteProgram {
     modules.add(cfgInjector.getInstance(GerritGlobalModule.class));
     modules.add(new InternalAccountDirectory.Module());
     modules.add(new DefaultCacheFactory.Module());
-    modules.add(new SmtpEmailSender.Module());
+    if (emailModule != null) {
+      modules.add(emailModule);
+    } else {
+      modules.add(new SmtpEmailSender.Module());
+    }
     modules.add(new SignedTokenEmailTokenVerifier.Module());
     modules.add(new PluginRestApiModule());
     modules.add(new RestCacheAdminModule());

gerrit-server/BUCK

@@ -101,10 +101,12 @@ java_library(
     '//lib:gwtorm',
     '//lib:h2',
     '//lib:junit',
+    '//lib/auto:auto-value',
     '//lib/guice:guice',
     '//lib/guice:guice-servlet',
     '//lib/jgit:jgit',
     '//lib/jgit:junit',
+    '//lib/log:api',
     '//lib/log:impl_log4j',
     '//lib/log:log4j',
   ],

gerrit-server/src/main/java/com/google/gerrit/server/mail/EmailHeader.java

@@ -14,6 +14,8 @@
 
 package com.google.gerrit.server.mail;
 
+import com.google.common.base.MoreObjects;
+
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.io.Writer;
@@ -23,6 +25,7 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
+import java.util.Objects;
 
 public abstract class EmailHeader {
   public abstract boolean isEmpty();
@@ -30,7 +33,7 @@ public abstract class EmailHeader {
   public abstract void write(Writer w) throws IOException;
 
   public static class String extends EmailHeader {
-    private java.lang.String value;
+    private final java.lang.String value;
 
     public String(java.lang.String v) {
       value = v;
@@ -53,6 +56,22 @@ public abstract class EmailHeader {
         w.write(value);
       }
     }
+
+    @Override
+    public int hashCode() {
+      return Objects.hashCode(value);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      return (o instanceof String)
+          && Objects.equals(value, ((String) o).value);
+    }
+
+    @Override
+    public java.lang.String toString() {
+      return MoreObjects.toStringHelper(this).addValue(value).toString();
+    }
   }
 
   static boolean needsQuotedPrintable(java.lang.String value) {
@@ -113,7 +132,7 @@ public abstract class EmailHeader {
   }
 
   public static class Date extends EmailHeader {
-    private java.util.Date value;
+    private final java.util.Date value;
 
     public Date(java.util.Date v) {
       value = v;
@@ -135,6 +154,22 @@ public abstract class EmailHeader {
       fmt = new SimpleDateFormat("EEE, d MMM yyyy HH:mm:ss Z", Locale.ENGLISH);
       w.write(fmt.format(value));
     }
+
+    @Override
+    public int hashCode() {
+      return Objects.hashCode(value);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      return (o instanceof Date)
+          && Objects.equals(value, ((Date) o).value);
+    }
+
+    @Override
+    public java.lang.String toString() {
+      return MoreObjects.toStringHelper(this).addValue(value).toString();
+    }
   }
 
   public static class AddressList extends EmailHeader {
@@ -191,5 +226,21 @@ public abstract class EmailHeader {
         needComma = true;
       }
     }
+
+    @Override
+    public int hashCode() {
+      return Objects.hashCode(list);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      return (o instanceof AddressList)
+          && Objects.equals(list, ((AddressList) o).list);
+    }
+
+    @Override
+    public java.lang.String toString() {
+      return MoreObjects.toStringHelper(this).addValue(list).toString();
+    }
   }
 }

gerrit-server/src/test/java/com/google/gerrit/testutil/FakeEmailSender.java

@@ -0,0 +1,119 @@
+// Copyright (C) 2015 The Android Open Source Project
+//
+// 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.gerrit.testutil;
+
+import com.google.auto.value.AutoValue;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import com.google.gerrit.common.errors.EmailException;
+import com.google.gerrit.server.git.WorkQueue;
+import com.google.gerrit.server.mail.Address;
+import com.google.gerrit.server.mail.EmailHeader;
+import com.google.gerrit.server.mail.EmailSender;
+import com.google.inject.AbstractModule;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ExecutionException;
+
+/**
+ * Email sender implementation that records messages in memory.
+ * <p>
+ * This class is mostly threadsafe. The only exception is that not all {@link
+ * EmailHeader} subclasses are immutable. In particular, if a caller holds a
+ * reference to an {@code AddressList} and mutates it after sending, the message
+ * returned by {@link #getMessages()} may or may not reflect mutations.
+ */
+@Singleton
+public class FakeEmailSender implements EmailSender {
+  private static final Logger log =
+      LoggerFactory.getLogger(FakeEmailSender.class);
+
+  public static class Module extends AbstractModule {
+    @Override
+    public void configure() {
+      bind(EmailSender.class).to(FakeEmailSender.class);
+    }
+  }
+
+  @AutoValue
+  public abstract static class Message {
+    private static Message create(Address from, Collection<Address> rcpt,
+        Map<String, EmailHeader> headers, String body) {
+      return new AutoValue_FakeEmailSender_Message(from,
+          ImmutableList.copyOf(rcpt), ImmutableMap.copyOf(headers), body);
+    }
+
+    public abstract Address from();
+    public abstract ImmutableList<Address> rcpt();
+    public abstract ImmutableMap<String, EmailHeader> headers();
+    public abstract String body();
+  }
+
+  private final WorkQueue workQueue;
+  private final List<Message> messages;
+
+  @Inject
+  FakeEmailSender(WorkQueue workQueue) {
+    this.workQueue = workQueue;
+    messages = Collections.synchronizedList(new ArrayList<Message>());
+  }
+
+  @Override
+  public boolean isEnabled() {
+    return true;
+  }
+
+  @Override
+  public boolean canEmail(String address) {
+    return true;
+  }
+
+  @Override
+  public void send(Address from, Collection<Address> rcpt,
+      Map<String, EmailHeader> headers, String body) throws EmailException {
+    messages.add(Message.create(from, rcpt, headers, body));
+  }
+
+  public ImmutableList<Message> getMessages() {
+    waitForEmails();
+    synchronized (messages) {
+      return ImmutableList.copyOf(messages);
+    }
+  }
+
+  private void waitForEmails() {
+    // TODO(dborowitz): This is brittle; consider forcing emails to use
+    // a single thread in tests (tricky because most callers just use the
+    // default executor).
+    for (WorkQueue.Task<?> task : workQueue.getTasks()) {
+      if (task.toString().contains("send-email")) {
+        try {
+          task.get();
+        } catch (ExecutionException | InterruptedException e) {
+          log.warn("error finishing email task", e);
+        }
+      }
+    }
+  }
+}

gerrit-server/src/test/java/com/google/gerrit/testutil/InMemoryModule.java

@@ -46,7 +46,6 @@ import com.google.gerrit.server.git.WorkQueue;
 import com.google.gerrit.server.index.ChangeSchemas;
 import com.google.gerrit.server.index.IndexModule.IndexType;
 import com.google.gerrit.server.mail.SignedTokenEmailTokenVerifier;
-import com.google.gerrit.server.mail.SmtpEmailSender;
 import com.google.gerrit.server.patch.DiffExecutor;
 import com.google.gerrit.server.schema.DataSourceType;
 import com.google.gerrit.server.schema.SchemaCreator;
@@ -88,7 +87,6 @@ public class InMemoryModule extends FactoryModule {
     cfg.setString("gerrit", null, "allProjects", "Test-Projects");
     cfg.setString("user", null, "name", "Gerrit Code Review");
     cfg.setString("user", null, "email", "gerrit@localhost");
-    cfg.setBoolean("sendemail", null, "enable", false);
     cfg.setString("cache", null, "directory", null);
     cfg.setString("index", null, "type", "lucene");
     cfg.setBoolean("index", "lucene", "testInmemory", true);
@@ -179,7 +177,7 @@ public class InMemoryModule extends FactoryModule {
       }
     });
     install(new DefaultCacheFactory.Module());
-    install(new SmtpEmailSender.Module());
+    install(new FakeEmailSender.Module());
     install(new SignedTokenEmailTokenVerifier.Module());
 
     IndexType indexType = null;