add tests for varint compatability with parseDelimitedFrom and writeD…

…elimitedTo

servicetalk-data-protobuf/build.gradle

@@ -43,6 +43,7 @@ dependencies {
   testImplementation project(":servicetalk-test-resources")
   testImplementation project(":servicetalk-buffer-netty")
   testImplementation "org.junit.jupiter:junit-jupiter-api:$junit5Version"
+  testImplementation "org.junit.jupiter:junit-jupiter-params:$junit5Version"
   testImplementation "org.hamcrest:hamcrest-library:$hamcrestVersion"
   testImplementation "org.mockito:mockito-core:$mockitoCoreVersion"
 

servicetalk-data-protobuf/src/test/java/io/servicetalk/data/protobuf/VarIntLengthStreamingSerializerTest.java

@@ -0,0 +1,105 @@
+/*
+ * Copyright © 2021 Apple Inc. and the ServiceTalk project authors
+ *
+ * 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 io.servicetalk.data.protobuf;
+
+import io.servicetalk.buffer.api.Buffer;
+import io.servicetalk.data.protobuf.test.TestProtos.DummyMessage;
+import io.servicetalk.serializer.utils.VarIntLengthStreamingSerializer;
+
+import com.google.protobuf.Parser;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.io.OutputStream;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+import java.util.stream.Stream;
+
+import static io.servicetalk.buffer.api.Buffer.asInputStream;
+import static io.servicetalk.buffer.api.Buffer.asOutputStream;
+import static io.servicetalk.buffer.netty.BufferAllocators.DEFAULT_ALLOCATOR;
+import static io.servicetalk.concurrent.api.Publisher.from;
+import static io.servicetalk.concurrent.api.Publisher.fromIterable;
+import static io.servicetalk.data.protobuf.test.TestProtos.DummyMessage.parser;
+import static java.util.Arrays.asList;
+import static java.util.Collections.singletonList;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.contains;
+
+class VarIntLengthStreamingSerializerTest {
+    private static final List<Arguments> POJOS = Arrays.asList(
+            Arguments.of(singletonList(newMsg("hello"))),
+            Arguments.of(asList(newMsg("hello"), newMsg("world"))),
+            Arguments.of(asList(newMsg("hello"), newMsg("world"), newMsg("!"))),
+            Arguments.of(asList(newMsg("hello"), newMsg(1 << 7))),
+            Arguments.of(asList(newMsg(1 << 14), newMsg("!"))),
+            Arguments.of(singletonList(newMsg(1 << 21))),
+            Arguments.of(singletonList(newMsg(1 << 28)))
+    );
+
+    @ParameterizedTest(name = "pojos={0}")
+    @MethodSource("pojos")
+    void protobufWriteDelimitedToDeserialized(Collection<DummyMessage> msgs) throws Exception {
+        Parser<DummyMessage> parser = DummyMessage.parser();
+        VarIntLengthStreamingSerializer<DummyMessage> serializer = new VarIntLengthStreamingSerializer<>(
+                ProtobufSerializerCache.INSTANCE.serializerDeserializer(parser), DummyMessage::getSerializedSize);
+
+        Buffer buffer = DEFAULT_ALLOCATOR.newBuffer();
+        OutputStream os = asOutputStream(buffer);
+        for (DummyMessage msg : msgs) {
+            msg.writeDelimitedTo(os);
+        }
+
+        assertThat(serializer.deserialize(from(buffer), DEFAULT_ALLOCATOR).toFuture().get(), contains(msgs.toArray()));
+    }
+
+    @ParameterizedTest(name = "pojos={0}")
+    @MethodSource("pojos")
+    void protobufParseDelimitedFromSerialized(Collection<DummyMessage> msgs) throws Exception {
+        Parser<DummyMessage> parser = parser();
+        VarIntLengthStreamingSerializer<DummyMessage> serializer = new VarIntLengthStreamingSerializer<>(
+                ProtobufSerializerCache.INSTANCE.serializerDeserializer(parser), DummyMessage::getSerializedSize);
+
+        Collection<Buffer> serialized = serializer.serialize(fromIterable(msgs), DEFAULT_ALLOCATOR)
+                .toFuture().get();
+
+        Collection<DummyMessage> deserialized = new ArrayList<>(serialized.size());
+        for (Buffer buf : serialized) {
+            deserialized.add(parser.parseDelimitedFrom(asInputStream(buf)));
+        }
+        assertThat(deserialized, contains(msgs.toArray()));
+    }
+
+    @SuppressWarnings("unused")
+    private static Stream<Arguments> pojos() {
+        return POJOS.stream();
+    }
+
+    private static DummyMessage newMsg(String msg) {
+        return DummyMessage.newBuilder().setMessage(msg).build();
+    }
+
+    private static DummyMessage newMsg(int length) {
+        StringBuilder sb = new StringBuilder(length);
+        for (int i = 0; i < length; ++i) {
+            sb.append('a');
+        }
+        return newMsg(sb.toString());
+    }
+}