Ensure Serializer runtime exceptions are rethrown as IOException (#6969)

exporters/common/src/main/java/io/opentelemetry/exporter/internal/marshal/Serializer.java

@@ -9,6 +9,7 @@ import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.sdk.internal.DynamicPrimitiveLongList;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.nio.ByteBuffer;
 import java.util.Collection;
 import java.util.List;
@@ -535,7 +536,11 @@ public abstract class Serializer implements AutoCloseable {
     if (!messages.isEmpty()) {
       RepeatedElementWriter<T> writer = context.getInstance(key, RepeatedElementWriter::new);
       writer.initialize(field, this, marshaler, context);
-      messages.forEach(writer);
+      try {
+        messages.forEach(writer);
+      } catch (UncheckedIOException e) {
+        throw e.getCause();
+      }
     }
 
     writeEndRepeated();
@@ -559,7 +564,11 @@ public abstract class Serializer implements AutoCloseable {
       RepeatedElementPairWriter<K, V> writer =
           context.getInstance(key, RepeatedElementPairWriter::new);
       writer.initialize(field, this, marshaler, context);
-      messages.forEach(writer);
+      try {
+        messages.forEach(writer);
+      } catch (UncheckedIOException e) {
+        throw e.getCause();
+      }
     }
 
     writeEndRepeated();
@@ -582,7 +591,11 @@ public abstract class Serializer implements AutoCloseable {
       RepeatedElementPairWriter<AttributeKey<?>, Object> writer =
           context.getInstance(ATTRIBUTES_WRITER_KEY, RepeatedElementPairWriter::new);
       writer.initialize(field, this, marshaler, context);
-      attributes.forEach(writer);
+      try {
+        attributes.forEach(writer);
+      } catch (UncheckedIOException e) {
+        throw e.getCause();
+      }
     }
 
     writeEndRepeated();
@@ -619,7 +632,7 @@ public abstract class Serializer implements AutoCloseable {
         marshaler.writeTo(output, element, context);
         output.writeEndRepeatedElement();
       } catch (IOException e) {
-        throw new IllegalStateException(e);
+        throw new UncheckedIOException(e);
       }
     }
   }
@@ -655,7 +668,7 @@ public abstract class Serializer implements AutoCloseable {
         marshaler.writeTo(output, key, value, context);
         output.writeEndRepeatedElement();
       } catch (IOException e) {
-        throw new IllegalStateException(e);
+        throw new UncheckedIOException(e);
       }
     }
   }

exporters/common/src/test/java/io/opentelemetry/exporter/internal/marshal/MarshalerTest.java

@@ -11,9 +11,17 @@ import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.Mockito.doThrow;
 import static org.mockito.Mockito.mock;
 
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.util.Collections;
+import java.util.stream.Stream;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
 
 class MarshalerTest {
 
@@ -47,4 +55,123 @@ class MarshalerTest {
     assertThatThrownBy(() -> marshaler.writeBinaryTo(os)).isInstanceOf(IOException.class);
     assertThatThrownBy(() -> marshaler.writeJsonTo(os)).isInstanceOf(IOException.class);
   }
+
+  /**
+   * This test ensures that instances where serializer produces runtime exceptions are properly
+   * converted back to checked {@link IOException}.
+   *
+   * <p>At various points in {@link Serializer}, we use {@code .forEach}-style methods which accept
+   * {@link java.util.function.Consumer} and {@link java.util.function.BiConsumer}. These consumers
+   * that any checked exceptions are caught and rethrown as runtime exceptions. Its essential that
+   * these runtime exceptions are re-converted back to checked {@link IOException} because calling
+   * code's error handling is built on top of {@link IOException}. Failure to convert to {@link
+   * IOException} leads to issues like this: <a
+   * href="https://github.com/open-telemetry/opentelemetry-java/issues/6946">#6946</a>.
+   */
+  @ParameterizedTest
+  @MethodSource("writeToArgs")
+  void writeTo_NoRuntimeExceptions(Writer writer) throws IOException {
+    Marshaler marshaler =
+        new Marshaler() {
+          @Override
+          public int getBinarySerializedSize() {
+            return 0;
+          }
+
+          @Override
+          protected void writeTo(Serializer output) throws IOException {
+            writer.writeTo(output);
+          }
+        };
+
+    try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
+      assertThatThrownBy(() -> marshaler.writeBinaryTo(baos)).isInstanceOf(IOException.class);
+    }
+  }
+
+  private static Stream<Arguments> writeToArgs() {
+    ProtoFieldInfo fieldInfo = ProtoFieldInfo.create(0, 0, "name");
+    MarshalerContext context = new MarshalerContext();
+    ThrowingMarshaler<String> throwingMarshaler = new ThrowingMarshaler<>(new IOException("error"));
+    ThrowingMarshaler2<String, String> throwingMarshaler2 =
+        new ThrowingMarshaler2<>(new IOException("error"));
+    ThrowingMarshaler2<AttributeKey<?>, Object> throwingMarshaler2Attributes =
+        new ThrowingMarshaler2<>(new IOException("error"));
+
+    return Stream.of(
+        Arguments.of(
+            asWriter(
+                output ->
+                    output.serializeRepeatedMessageWithContext(
+                        fieldInfo,
+                        Collections.singleton("value"),
+                        throwingMarshaler,
+                        context,
+                        MarshalerContext.key()))),
+        Arguments.of(
+            asWriter(
+                output ->
+                    output.serializeRepeatedMessageWithContext(
+                        fieldInfo,
+                        Collections.singletonMap("key", "value"),
+                        throwingMarshaler2,
+                        context,
+                        MarshalerContext.key()))),
+        Arguments.of(
+            asWriter(
+                output ->
+                    output.serializeRepeatedMessageWithContext(
+                        fieldInfo,
+                        Attributes.builder().put("key", "value").build(),
+                        throwingMarshaler2Attributes,
+                        context))));
+  }
+
+  private static Writer asWriter(Writer writer) {
+    return writer;
+  }
+
+  @FunctionalInterface
+  private interface Writer {
+    void writeTo(Serializer output) throws IOException;
+  }
+
+  private static class ThrowingMarshaler<T> implements StatelessMarshaler<T> {
+
+    private final IOException exception;
+
+    private ThrowingMarshaler(IOException exception) {
+      this.exception = exception;
+    }
+
+    @Override
+    public int getBinarySerializedSize(T value, MarshalerContext context) {
+      return 0;
+    }
+
+    @Override
+    public void writeTo(Serializer output, T value, MarshalerContext context) throws IOException {
+      throw exception;
+    }
+  }
+
+  private static class ThrowingMarshaler2<K, V> implements StatelessMarshaler2<K, V> {
+
+    private final IOException exception;
+
+    private ThrowingMarshaler2(IOException exception) {
+      this.exception = exception;
+    }
+
+    @Override
+    public int getBinarySerializedSize(K key, V value, MarshalerContext context) {
+      return 0;
+    }
+
+    @Override
+    public void writeTo(Serializer output, K key, V value, MarshalerContext context)
+        throws IOException {
+      throw exception;
+    }
+  }
 }