diff --git a/services/inputflinger/tests/Android.bp b/services/inputflinger/tests/Android.bp
index 300bb85..370e971 100644
--- a/services/inputflinger/tests/Android.bp
+++ b/services/inputflinger/tests/Android.bp
@@ -59,6 +59,7 @@
         "NotifyArgs_test.cpp",
         "PreferStylusOverTouch_test.cpp",
         "PropertyProvider_test.cpp",
+        "SlopController_test.cpp",
         "SyncQueue_test.cpp",
         "TestInputListener.cpp",
         "TouchpadInputMapper_test.cpp",
diff --git a/services/inputflinger/tests/SlopController_test.cpp b/services/inputflinger/tests/SlopController_test.cpp
new file mode 100644
index 0000000..f524acd
--- /dev/null
+++ b/services/inputflinger/tests/SlopController_test.cpp
@@ -0,0 +1,99 @@
+/*
+ * Copyright 2023 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.
+ */
+
+#include "../reader/mapper/SlopController.h"
+
+#include <gtest/gtest.h>
+
+namespace android {
+
+// --- SlopControllerTest ---
+
+TEST(SlopControllerTest, PositiveValues) {
+    SlopController controller = SlopController(/*slopThreshold=*/5, /*slopDurationNanos=*/100);
+
+    ASSERT_EQ(0, controller.consumeEvent(1000, 1));
+    ASSERT_EQ(0, controller.consumeEvent(1003, 3));
+    ASSERT_EQ(2, controller.consumeEvent(1005, 3));
+    ASSERT_EQ(4, controller.consumeEvent(1009, 4));
+
+    SlopController controller2 = SlopController(/*slopThreshold=*/5, /*slopDurationNanos=*/100);
+
+    ASSERT_EQ(0, controller2.consumeEvent(1000, 5));
+    ASSERT_EQ(3, controller2.consumeEvent(1003, 3));
+    ASSERT_EQ(4, controller2.consumeEvent(1005, 4));
+}
+
+TEST(SlopControllerTest, NegativeValues) {
+    SlopController controller = SlopController(/*slopThreshold=*/5, /*slopDurationNanos=*/100);
+
+    ASSERT_EQ(0, controller.consumeEvent(1000, -1));
+    ASSERT_EQ(0, controller.consumeEvent(1003, -3));
+    ASSERT_EQ(-2, controller.consumeEvent(1005, -3));
+    ASSERT_EQ(-4, controller.consumeEvent(1009, -4));
+
+    SlopController controller2 = SlopController(/*slopThreshold=*/5, /*slopDurationNanos=*/100);
+
+    ASSERT_EQ(0, controller2.consumeEvent(1000, -5));
+    ASSERT_EQ(-3, controller2.consumeEvent(1003, -3));
+    ASSERT_EQ(-4, controller2.consumeEvent(1005, -4));
+}
+
+TEST(SlopControllerTest, ZeroDoesNotResetSlop) {
+    SlopController controller = SlopController(/*slopThreshold=*/5, /*slopDurationNanos=*/100);
+
+    ASSERT_EQ(1, controller.consumeEvent(1005, 6));
+    ASSERT_EQ(0, controller.consumeEvent(1006, 0));
+    ASSERT_EQ(2, controller.consumeEvent(1008, 2));
+}
+
+TEST(SlopControllerTest, SignChange_ResetsSlop) {
+    SlopController controller = SlopController(/*slopThreshold=*/5, /*slopDurationNanos=*/100);
+
+    ASSERT_EQ(0, controller.consumeEvent(1000, 2));
+    ASSERT_EQ(0, controller.consumeEvent(1001, -4));
+    ASSERT_EQ(0, controller.consumeEvent(1002, 3));
+    ASSERT_EQ(0, controller.consumeEvent(1003, -2));
+
+    ASSERT_EQ(1, controller.consumeEvent(1005, 6));
+    ASSERT_EQ(0, controller.consumeEvent(1006, 0));
+    ASSERT_EQ(2, controller.consumeEvent(1008, 2));
+
+    ASSERT_EQ(0, controller.consumeEvent(1010, -4));
+    ASSERT_EQ(-1, controller.consumeEvent(1011, -2));
+
+    ASSERT_EQ(0, controller.consumeEvent(1015, 5));
+    ASSERT_EQ(2, controller.consumeEvent(1016, 2));
+
+    ASSERT_EQ(0, controller.consumeEvent(1017, -5));
+    ASSERT_EQ(-2, controller.consumeEvent(1018, -2));
+}
+
+TEST(SlopControllerTest, OldAge_ResetsSlop) {
+    SlopController controller = SlopController(/*slopThreshold=*/5, /*slopDurationNanos=*/100);
+
+    ASSERT_EQ(1, controller.consumeEvent(1005, 6));
+    ASSERT_EQ(0, controller.consumeEvent(1108, 2)); // age exceeds slop duration
+
+    ASSERT_EQ(1, controller.consumeEvent(1110, 4));
+    ASSERT_EQ(0, controller.consumeEvent(1210, 2)); // age equals slop duration
+
+    ASSERT_EQ(0, controller.consumeEvent(1215, -3));
+    ASSERT_EQ(-2, controller.consumeEvent(1216, -4));
+    ASSERT_EQ(-5, controller.consumeEvent(1315, -5));
+}
+
+} // namespace android