Cache function add basic cache structure

Test: unit test test save and retrieve info it works correctly
Bug: 202335820
Change-Id: Ic4a316bf265b89a8bc134335f2d06ef117cf0c80
diff --git a/nearby/tests/Android.bp b/nearby/tests/Android.bp
index f74228a..fc0a700 100644
--- a/nearby/tests/Android.bp
+++ b/nearby/tests/Android.bp
@@ -34,6 +34,11 @@
 
     static_libs: [
         "androidx.test.rules",
+        "compatibility-device-util-axt",
+        "service-appsearch",
+        "truth-prebuilt",
+        "androidx.test.ext.junit",
+        "junit",
         "framework-nearby-pre-jarjar",
         "guava",
         "robolectric_android-all-stub",
diff --git a/nearby/tests/src/com/android/server/nearby/fastpair/cache/FastPairCacheManagerTest.java b/nearby/tests/src/com/android/server/nearby/fastpair/cache/FastPairCacheManagerTest.java
new file mode 100644
index 0000000..adbb12a
--- /dev/null
+++ b/nearby/tests/src/com/android/server/nearby/fastpair/cache/FastPairCacheManagerTest.java
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2021 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.android.server.nearby.fastpair.cache;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.when;
+
+import android.content.Context;
+
+import androidx.test.core.app.ApplicationProvider;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import service.proto.Cache;
+
+public class FastPairCacheManagerTest {
+
+    private static final String MODEL_ID = "001";
+    private static final String APP_NAME = "APP_NAME";
+    @Mock
+    DiscoveryItem mDiscoveryItem;
+    Cache.StoredDiscoveryItem mStoredDiscoveryItem = Cache.StoredDiscoveryItem.newBuilder()
+            .setTriggerId(MODEL_ID)
+            .setAppName(APP_NAME).build();
+
+    @Before
+    public void setup() {
+        MockitoAnnotations.initMocks(this);
+    }
+
+    @Test
+    public void notSaveRetrieveInfo() {
+        Context mContext = ApplicationProvider.getApplicationContext();
+        when(mDiscoveryItem.getCopyOfStoredItem()).thenReturn(mStoredDiscoveryItem);
+        when(mDiscoveryItem.getTriggerId()).thenReturn(MODEL_ID);
+
+        FastPairCacheManager fastPairCacheManager = new FastPairCacheManager(mContext);
+
+        assertThat(fastPairCacheManager.getStoredDiscoveryItem(MODEL_ID).getAppName())
+                .isNotEqualTo(APP_NAME);
+    }
+
+    @Test
+    public void saveRetrieveInfo() {
+        Context mContext = ApplicationProvider.getApplicationContext();
+        when(mDiscoveryItem.getCopyOfStoredItem()).thenReturn(mStoredDiscoveryItem);
+        when(mDiscoveryItem.getTriggerId()).thenReturn(MODEL_ID);
+
+        FastPairCacheManager fastPairCacheManager = new FastPairCacheManager(mContext);
+        fastPairCacheManager.saveDiscoveryItem(mDiscoveryItem);
+        assertThat(fastPairCacheManager.getStoredDiscoveryItem(MODEL_ID).getAppName())
+                .isEqualTo(APP_NAME);
+    }
+}