Remove expectedResolvedLength from DataSourceContractTest

Whether a resource resolves to a known length or not is more than just
a property of the resource & data source - for example if
`DataSpec.flags` contains `ALLOW_GZIP` then the length might be
unresolved. More generally, a `DataSource` could randomly return
`C.UNKNOWN_LENGTH` from `open()` 50% of the time and still fulfil the
`DataSource` interface. This makes it ~impossible to write a meaningful
assertion aroun this.

So this change relaxes the assertion slightly to more closely match the
definition of the `DataSource` interface.

We leave the `resolveToUnknownLength` toggle in
`WebServerDispatcher.Resource` because this is still useful for
simulating the case of a server that is serving a file it doesn't
know the length of.

PiperOrigin-RevId: 351124246

library/core/src/androidTest/java/com/google/android/exoplayer2/upstream/ContentDataSourceContractTest.java

@@ -48,7 +48,6 @@ public final class ContentDataSourceContractTest extends DataSourceContractTest
             .setName("simple (pipe=true)")
             .setUri(TestContentProvider.buildUri(DATA_PATH, /* pipeMode= */ true))
             .setExpectedBytes(completeData)
-            .setResolvesToUnknownLength(true)
             .build());
   }
 

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

@@ -135,7 +135,6 @@ public class DefaultHttpDataSourceContractTest extends DataSourceContractTest {
         .setName(name)
         .setUri(Uri.parse(urlResolver.apply(resource.getPath()).toString()))
         .setExpectedBytes(resource.getData())
-        .setResolvesToUnknownLength(resource.resolvesToUnknownLength())
         .setEndOfInputExpected(!resource.resolvesToUnknownLength())
         .build();
   }

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

@@ -60,7 +60,6 @@ public class UdpDataSourceContractTest extends DataSourceContractTest {
             .setName("local-udp-unicast-socket")
             .setUri(Uri.parse("udp://localhost:" + findFreeUdpPort()))
             .setExpectedBytes(data)
-            .setResolvesToUnknownLength(true)
             .setEndOfInputExpected(false)
             .build());
   }

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

@@ -93,7 +93,9 @@ public abstract class DataSourceContractTest {
                 ? Util.readToEnd(dataSource)
                 : Util.readExactly(dataSource, resource.getExpectedBytes().length);
 
-        assertThat(length).isEqualTo(resource.getExpectedResolvedLength());
+        if (length != C.LENGTH_UNSET) {
+          assertThat(length).isEqualTo(resource.getExpectedBytes().length);
+        }
         assertThat(data).isEqualTo(resource.getExpectedBytes());
       } finally {
         dataSource.close();
@@ -120,8 +122,8 @@ public abstract class DataSourceContractTest {
                 ? Util.readToEnd(dataSource)
                 : Util.readExactly(dataSource, resource.getExpectedBytes().length - 3);
 
-        if (resource.getExpectedResolvedLength() != C.LENGTH_UNSET) {
-          assertThat(length).isEqualTo(resource.getExpectedResolvedLength() - 3);
+        if (length != C.LENGTH_UNSET) {
+          assertThat(length).isEqualTo(resource.getExpectedBytes().length - 3);
         }
         byte[] expectedData =
             Arrays.copyOfRange(resource.getExpectedBytes(), 3, resource.getExpectedBytes().length);
@@ -219,19 +221,13 @@ public abstract class DataSourceContractTest {
     @Nullable private final String name;
     private final Uri uri;
     private final byte[] expectedBytes;
-    private final boolean resolvesToUnknownLength;
     private final boolean endOfInputExpected;
 
     private TestResource(
-        @Nullable String name,
-        Uri uri,
-        byte[] expectedBytes,
-        boolean resolvesToUnknownLength,
-        boolean endOfInputExpected) {
+        @Nullable String name, Uri uri, byte[] expectedBytes, boolean endOfInputExpected) {
       this.name = name;
       this.uri = uri;
       this.expectedBytes = expectedBytes;
-      this.resolvesToUnknownLength = resolvesToUnknownLength;
       this.endOfInputExpected = endOfInputExpected;
     }
 
@@ -251,16 +247,6 @@ public abstract class DataSourceContractTest {
       return expectedBytes;
     }
 
-    /**
-     * Returns the expected resolved length of this resource.
-     *
-     * <p>This is either {@link #getExpectedBytes() getExpectedBytes().length} or {@link
-     * C#LENGTH_UNSET}.
-     */
-    public long getExpectedResolvedLength() {
-      return resolvesToUnknownLength ? C.LENGTH_UNSET : expectedBytes.length;
-    }
-
     /**
      * Returns whether {@link DataSource#read} is expected to return {@link C#RESULT_END_OF_INPUT}
      * after all the resource data are read.
@@ -274,7 +260,6 @@ public abstract class DataSourceContractTest {
       private @MonotonicNonNull String name;
       private @MonotonicNonNull Uri uri;
       private byte @MonotonicNonNull [] expectedBytes;
-      private boolean resolvesToUnknownLength;
       private boolean endOfInputExpected;
 
       /** Construct a new instance. */
@@ -307,16 +292,6 @@ public abstract class DataSourceContractTest {
         return this;
       }
 
-      /**
-       * Sets whether {@link DataSource#open(DataSpec)} is expected to return {@link C#LENGTH_UNSET}
-       * when passed the URI of this resource and a {@link DataSpec} with {@code length ==
-       * C.LENGTH_UNSET}.
-       */
-      public Builder setResolvesToUnknownLength(boolean value) {
-        this.resolvesToUnknownLength = value;
-        return this;
-      }
-
       /**
        * Sets whether {@link DataSource#read} is expected to return {@link C#RESULT_END_OF_INPUT}
        * after all the resource data have been read. By default, this is set to {@code true}.
@@ -328,11 +303,7 @@ public abstract class DataSourceContractTest {
 
       public TestResource build() {
         return new TestResource(
-            name,
-            checkNotNull(uri),
-            checkNotNull(expectedBytes),
-            resolvesToUnknownLength,
-            endOfInputExpected);
+            name, checkNotNull(uri), checkNotNull(expectedBytes), endOfInputExpected);
       }
     }
   }

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

@@ -91,6 +91,9 @@ public class WebServerDispatcher extends Dispatcher {
       /**
        * Sets if the resource should resolve to an unknown length. Defaults to false.
        *
+       * <p>If true, responses to unbound requests won't include a Content-Length header and
+       * Content-Range headers won't include the total resource length.
+       *
        * @return this builder, for convenience.
        */
       public Builder resolvesToUnknownLength(boolean resolvesToUnknownLength) {
@@ -133,12 +136,7 @@ public class WebServerDispatcher extends Dispatcher {
       return supportsRangeRequests;
     }
 
-    /**
-     * Returns true if the server shouldn't include the resource length in header responses.
-     *
-     * <p>Responses to unbound requests won't include a Content-Length header, and Content-Range
-     * headers won't include the total resource length.
-     */
+    /** Returns true if the resource should resolve to an unknown length. */
     public boolean resolvesToUnknownLength() {
       return resolvesToUnknownLength;
     }