Add contract test for AssetDataSource

PiperOrigin-RevId: 352532853

library/core/src/test/java/com/google/android/exoplayer2/upstream/AssetDataSourceContractTest.java

@@ -0,0 +1,63 @@
+/*
+ * 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.google.android.exoplayer2.upstream;
+
+import android.net.Uri;
+import androidx.test.core.app.ApplicationProvider;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.testutil.DataSourceContractTest;
+import com.google.android.exoplayer2.testutil.TestUtil;
+import com.google.common.collect.ImmutableList;
+import java.io.IOException;
+import org.junit.Before;
+import org.junit.runner.RunWith;
+
+/** {@link DataSource} contract tests for {@link AssetDataSource}. */
+@RunWith(AndroidJUnit4.class)
+public class AssetDataSourceContractTest extends DataSourceContractTest {
+
+  // We pick an arbitrary file from the assets. The selected file has a convenient size of 1024
+  // bytes.
+  private static final String ASSET_PATH = "media/mp3/1024_incrementing_bytes.mp3";
+  private static final Uri ASSET_URI = Uri.parse("asset:///" + ASSET_PATH);
+
+  private byte[] data;
+
+  @Before
+  public void setUp() throws IOException {
+    data = TestUtil.getByteArray(ApplicationProvider.getApplicationContext(), ASSET_PATH);
+  }
+
+  @Override
+  protected ImmutableList<TestResource> getTestResources() {
+    return ImmutableList.of(
+        new TestResource.Builder()
+            .setName("simple")
+            .setUri(ASSET_URI)
+            .setExpectedBytes(data)
+            .build());
+  }
+
+  @Override
+  protected Uri getNotFoundUri() {
+    return Uri.parse("asset:///nonexistentdir/nonexistentfile");
+  }
+
+  @Override
+  protected DataSource createDataSource() {
+    return new AssetDataSource(ApplicationProvider.getApplicationContext());
+  }
+}