DataSourceContractTest: Check an unbounded subrange is read correctly

PiperOrigin-RevId: 347994829

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

@@ -29,6 +29,7 @@ import java.net.DatagramSocket;
 import java.net.InetAddress;
 import java.net.SocketException;
 import org.junit.Before;
+import org.junit.Ignore;
 import org.junit.runner.RunWith;
 
 /** {@link DataSource} contract tests for {@link UdpDataSource}. */
@@ -72,6 +73,29 @@ public class UdpDataSourceContractTest extends DataSourceContractTest {
     return Uri.parse("udp://notfound.invalid:12345");
   }
 
+  @Override
+  @Ignore("UdpDataSource doesn't support DataSpec's position or length [internal: b/175856954]")
+  public void dataSpecWithPosition_readUntilEnd() {}
+
+  /**
+   * Finds a free UDP port in the range of unreserved ports 50000-60000 that can be used from the
+   * test or throws an {@link IllegalStateException} if no port is available.
+   *
+   * <p>There is no guarantee that the port returned will still be available as another process may
+   * occupy it in the mean time.
+   */
+  private static int findFreeUdpPort() {
+    for (int i = 50000; i <= 60000; i++) {
+      try {
+        new DatagramSocket(i).close();
+        return i;
+      } catch (SocketException e) {
+        // Port is occupied, continue to next port.
+      }
+    }
+    throw new IllegalStateException();
+  }
+
   /**
    * A {@link TransferListener} that triggers UDP packet transmissions back to the UDP data source.
    */
@@ -109,23 +133,4 @@ public class UdpDataSourceContractTest extends DataSourceContractTest {
     @Override
     public void onTransferEnd(DataSource source, DataSpec dataSpec, boolean isNetwork) {}
   }
-
-  /**
-   * Finds a free UDP port in the range of unreserved ports 50000-60000 that can be used from the
-   * test or throws an {@link IllegalStateException} if no port is available.
-   *
-   * <p>There is no guarantee that the port returned will still be available as another process may
-   * occupy it in the mean time.
-   */
-  private static int findFreeUdpPort() {
-    for (int i = 50000; i <= 60000; i++) {
-      try {
-        new DatagramSocket(i).close();
-        return i;
-      } catch (SocketException e) {
-        // Port is occupied, continue to next port.
-      }
-    }
-    throw new IllegalStateException();
-  }
 }

testutils/src/main/java/com/google/android/exoplayer2/testutil/DataSourceContractTest.java

@@ -15,6 +15,7 @@
  */
 package com.google.android.exoplayer2.testutil;
 
+import static com.google.android.exoplayer2.util.Assertions.checkArgument;
 import static com.google.android.exoplayer2.util.Assertions.checkNotNull;
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.assertThrows;
@@ -29,6 +30,7 @@ import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableList;
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.List;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 import org.junit.Ignore;
@@ -86,10 +88,7 @@ public abstract class DataSourceContractTest {
       DataSource dataSource = createDataSource();
       try {
         long length = dataSource.open(new DataSpec(resource.getUri()));
-        byte[] data =
+        byte[] data = readToEnd(dataSource, resource);
-            resource.isEndOfInputExpected()
-                ? Util.readToEnd(dataSource)
-                : Util.readExactly(dataSource, resource.getExpectedBytes().length);
 
         assertThat(length).isEqualTo(resource.getExpectedResolvedLength());
         assertThat(data).isEqualTo(resource.getExpectedBytes());
@@ -100,6 +99,34 @@ public abstract class DataSourceContractTest {
     }
   }
 
+  @Test
+  public void dataSpecWithPosition_readUntilEnd() throws Exception {
+    ImmutableList<TestResource> resources = getTestResources();
+    Assertions.checkArgument(!resources.isEmpty(), "Must provide at least one test resource.");
+
+    for (int i = 0; i < resources.size(); i++) {
+      additionalFailureInfo.setInfo(getFailureLabel(resources, i));
+      TestResource resource = resources.get(i);
+      DataSource dataSource = createDataSource();
+      try {
+        long length =
+            dataSource.open(
+                new DataSpec.Builder().setUri(resource.getUri()).setPosition(3).build());
+        byte[] data = readToEnd(dataSource, resource);
+
+        if (resource.getExpectedResolvedLength() != C.LENGTH_UNSET) {
+          assertThat(length).isEqualTo(resource.getExpectedResolvedLength() - 3);
+        }
+        byte[] expectedData =
+            Arrays.copyOfRange(resource.getExpectedBytes(), 3, resource.getExpectedBytes().length);
+        assertThat(data).isEqualTo(expectedData);
+      } finally {
+        dataSource.close();
+      }
+      additionalFailureInfo.setInfo(null);
+    }
+  }
+
   @Test
   public void resourceNotFound() throws Exception {
     DataSource dataSource = createDataSource();
@@ -121,6 +148,13 @@ public abstract class DataSourceContractTest {
     }
   }
 
+  private static byte[] readToEnd(DataSource dataSource, TestResource expectedResource)
+      throws IOException {
+    return expectedResource.isEndOfInputExpected()
+        ? Util.readToEnd(dataSource)
+        : Util.readExactly(dataSource, expectedResource.getExpectedBytes().length);
+  }
+
   /** Information about a resource that can be used to test the {@link DataSource} instance. */
   public static final class TestResource {
 
@@ -204,8 +238,13 @@ public abstract class DataSourceContractTest {
         return this;
       }
 
-      /** Sets the expected contents of this resource. */
+      /**
+       * Sets the expected contents of this resource.
+       *
+       * <p>Must be at least 5 bytes.
+       */
       public Builder setExpectedBytes(byte[] expectedBytes) {
+        checkArgument(expectedBytes.length >= 5);
         this.expectedBytes = expectedBytes;
         return this;
       }