diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java b/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java
index b1fbb10..bfb7e95 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorage.java
@@ -64,7 +64,12 @@
 
   @Inject
   ReplicationTasksStorage(ReplicationConfig config) {
-    refUpdates = config.getEventsDirectory().resolve("ref-updates");
+    this(config.getEventsDirectory().resolve("ref-updates"));
+  }
+
+  @VisibleForTesting
+  public ReplicationTasksStorage(Path refUpdates) {
+    this.refUpdates = refUpdates;
   }
 
   public String persist(ReplicateRefUpdate r) {
diff --git a/src/test/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorageTest.java b/src/test/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorageTest.java
new file mode 100644
index 0000000..3ee85d7
--- /dev/null
+++ b/src/test/java/com/googlesource/gerrit/plugins/replication/ReplicationTasksStorageTest.java
@@ -0,0 +1,227 @@
+// Copyright (C) 2020 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.googlesource.gerrit.plugins.replication;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
+
+import com.google.common.jimfs.Configuration;
+import com.google.common.jimfs.Jimfs;
+import com.googlesource.gerrit.plugins.replication.ReplicationTasksStorage.ReplicateRefUpdate;
+import java.net.URISyntaxException;
+import java.nio.file.FileSystem;
+import java.nio.file.Path;
+import java.util.Objects;
+import org.eclipse.jgit.transport.URIish;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class ReplicationTasksStorageTest {
+  protected static final String PROJECT = "myProject";
+  protected static final String REF = "myRef";
+  protected static final String REMOTE = "myDest";
+  protected static final URIish URISH = getUrish("http://example.com/" + PROJECT + ".git");
+  protected static final ReplicateRefUpdate REF_UPDATE =
+      new ReplicateRefUpdate(PROJECT, REF, URISH, REMOTE);
+
+  protected ReplicationTasksStorage storage;
+  protected FileSystem fileSystem;
+  protected Path storageSite;
+
+  @Before
+  public void setUp() throws Exception {
+    fileSystem = Jimfs.newFileSystem(Configuration.unix());
+    storageSite = fileSystem.getPath("replication_site");
+    storage = new ReplicationTasksStorage(storageSite);
+  }
+
+  @After
+  public void tearDown() throws Exception {
+    fileSystem.close();
+  }
+
+  @Test
+  public void canListEmptyStorage() throws Exception {
+    assertThat(storage.list()).isEmpty();
+  }
+
+  @Test
+  public void canListPersistedUpdate() throws Exception {
+    storage.persist(REF_UPDATE);
+    assertContainsExactly(storage, REF_UPDATE);
+  }
+
+  @Test
+  public void canDeletePersistedUpdate() throws Exception {
+    storage.persist(REF_UPDATE);
+    storage.delete(REF_UPDATE);
+    assertThat(storage.list()).isEmpty();
+  }
+
+  @Test
+  public void instancesOfTheSameStorageHaveTheSameElements() throws Exception {
+    ReplicationTasksStorage persistedView = new ReplicationTasksStorage(storageSite);
+
+    assertThat(storage.list()).isEmpty();
+    assertThat(persistedView.list()).isEmpty();
+
+    storage.persist(REF_UPDATE);
+    assertContainsExactly(storage, REF_UPDATE);
+    assertContainsExactly(persistedView, REF_UPDATE);
+
+    storage.delete(REF_UPDATE);
+    assertThat(storage.list()).isEmpty();
+    assertThat(persistedView.list()).isEmpty();
+  }
+
+  @Test
+  public void sameRefUpdatePersistedTwiceIsStoredOnce() throws Exception {
+    String key = storage.persist(REF_UPDATE);
+    String secondKey = storage.persist(REF_UPDATE);
+    assertEquals(key, secondKey);
+    assertContainsExactly(storage, REF_UPDATE);
+  }
+
+  @Test
+  public void canPersistDifferentUris() throws Exception {
+    ReplicateRefUpdate updateB =
+        new ReplicateRefUpdate(
+            PROJECT,
+            REF,
+            getUrish("ssh://example.com/" + PROJECT + ".git"), // uses ssh not http
+            REMOTE);
+
+    String keyA = storage.persist(REF_UPDATE);
+    String keyB = storage.persist(updateB);
+    assertThat(storage.list()).hasSize(2);
+    assertNotEquals(keyA, keyB);
+  }
+
+  @Test
+  public void canDeleteDifferentUris() throws Exception {
+    ReplicateRefUpdate updateB =
+        new ReplicateRefUpdate(
+            PROJECT,
+            REF,
+            getUrish("ssh://example.com/" + PROJECT + ".git"), // uses ssh not http
+            REMOTE);
+    storage.persist(REF_UPDATE);
+    storage.persist(updateB);
+
+    storage.delete(REF_UPDATE);
+    assertContainsExactly(storage, updateB);
+
+    storage.delete(updateB);
+    assertThat(storage.list()).isEmpty();
+  }
+
+  @Test
+  public void differentUrisPersistedTwiceIsStoredOnce() throws Exception {
+    ReplicateRefUpdate updateB =
+        new ReplicateRefUpdate(
+            PROJECT,
+            REF,
+            getUrish("ssh://example.com/" + PROJECT + ".git"), // uses ssh not http
+            REMOTE);
+
+    storage.persist(REF_UPDATE);
+    storage.persist(updateB);
+    storage.persist(REF_UPDATE);
+    storage.persist(updateB);
+    assertThat(storage.list()).hasSize(2);
+  }
+
+  @Test
+  public void canPersistMulipleRefsForSameUri() throws Exception {
+    ReplicateRefUpdate refA = new ReplicateRefUpdate(PROJECT, "refA", URISH, REMOTE);
+    ReplicateRefUpdate refB = new ReplicateRefUpdate(PROJECT, "refB", URISH, REMOTE);
+
+    String keyA = storage.persist(refA);
+    String keyB = storage.persist(refB);
+    assertThat(storage.list()).hasSize(2);
+    assertNotEquals(keyA, keyB);
+  }
+
+  @Test
+  public void canDeleteMulipleRefsForSameUri() throws Exception {
+    ReplicateRefUpdate refA = new ReplicateRefUpdate(PROJECT, "refA", URISH, REMOTE);
+    ReplicateRefUpdate refB = new ReplicateRefUpdate(PROJECT, "refB", URISH, REMOTE);
+    storage.persist(refA);
+    storage.persist(refB);
+
+    storage.delete(refA);
+    assertContainsExactly(storage, refB);
+
+    storage.delete(refB);
+    assertThat(storage.list()).isEmpty();
+  }
+
+  @Test(expected = Test.None.class /* no exception expected */)
+  public void illegalDeleteNonPersistedIsGraceful() throws Exception {
+    storage.delete(REF_UPDATE);
+  }
+
+  @Test(expected = Test.None.class /* no exception expected */)
+  public void illegalDoubleDeleteIsGraceful() throws Exception {
+    storage.persist(REF_UPDATE);
+    storage.delete(REF_UPDATE);
+
+    storage.delete(REF_UPDATE);
+  }
+
+  @Test(expected = Test.None.class /* no exception expected */)
+  public void illegalDoubleDeleteDifferentUriIsGraceful() throws Exception {
+    ReplicateRefUpdate updateB =
+        new ReplicateRefUpdate(
+            PROJECT,
+            REF,
+            getUrish("ssh://example.com/" + PROJECT + ".git"), // uses ssh not http
+            REMOTE);
+    storage.persist(REF_UPDATE);
+    storage.persist(updateB);
+    storage.delete(REF_UPDATE);
+    storage.delete(updateB);
+
+    storage.delete(REF_UPDATE);
+    storage.delete(updateB);
+    assertThat(storage.list()).isEmpty();
+  }
+
+  private void assertContainsExactly(
+      ReplicationTasksStorage tasksStorage, ReplicateRefUpdate update) {
+    assertTrue(equals(tasksStorage.list().get(0), update));
+  }
+
+  private boolean equals(ReplicateRefUpdate one, ReplicateRefUpdate two) {
+    return (one == null && two == null)
+        || (one != null
+            && two != null
+            && Objects.equals(one.project, two.project)
+            && Objects.equals(one.ref, two.ref)
+            && Objects.equals(one.remote, two.remote)
+            && Objects.equals(one.uri, two.uri));
+  }
+
+  public static URIish getUrish(String uri) {
+    try {
+      return new URIish(uri);
+    } catch (URISyntaxException e) {
+      throw new RuntimeException("Cannot instantiate URIish object", e);
+    }
+  }
+}