API Completeness

public abstract class ScalaAPICompletenessTestBase {
    protected static final Logger LOG = LoggerFactory.getLogger(ScalaAPICompletenessTestBase.class);
    
    // Core comparison methods
    protected void compareApis(Class<?> javaClass, Class<?> scalaClass);
    protected void compareApis(Class<?> javaClass, Class<?> scalaClass, Set<String> excludedMethods);
    
    // Method filtering and exclusion
    protected boolean isExcluded(Method method);
    protected boolean isExcluded(String methodName);
    protected Set<String> getExcludedMethods();
    
    // Comparison utilities
    protected boolean methodsMatch(Method javaMethod, Method scalaMethod);
    protected String getMethodSignature(Method method);
    protected void reportMissingMethods(Set<String> missingMethods, String apiType);
}

public abstract class TupleComparatorTestBase<T> {
    protected TypeComparator<T> javaComparator;
    protected TypeComparator<T> scalaComparator;
    
    @Before
    public abstract void setup();
    
    // Comparison testing methods
    protected void testComparatorEquality(T value1, T value2);
    protected void testComparatorSerialization();
    protected void testComparatorNormalization();
    
    // Utility methods
    protected abstract T[] getTestData();
    protected abstract TypeComparator<T> createJavaComparator();
    protected abstract TypeComparator<T> createScalaComparator();
}

public abstract class PairComparatorTestBase<T1, T2> {
    protected TypePairComparator<T1, T2> javaPairComparator;
    protected TypePairComparator<T1, T2> scalaPairComparator;
    
    @Before  
    public abstract void setup();
    
    // Pair comparison testing
    protected void testPairComparatorEquality(T1 first1, T2 second1, T1 first2, T2 second2);
    protected void testPairComparatorSerialization();
    
    // Abstract methods for test data
    protected abstract T1[] getFirstTypeTestData();
    protected abstract T2[] getSecondTypeTestData();
    protected abstract TypePairComparator<T1, T2> createJavaPairComparator();
    protected abstract TypePairComparator<T1, T2> createScalaPairComparator();
}

public class MethodSignatureComparator {
    public static boolean signaturesMatch(Method javaMethod, Method scalaMethod);
    public static String normalizeSignature(Method method);
    public static boolean returnTypesCompatible(Class<?> javaReturn, Class<?> scalaReturn);
    public static boolean parametersCompatible(Class<?>[] javaParams, Class<?>[] scalaParams);
}

public class ReflectionTestUtils {
    public static Set<Method> getPublicMethods(Class<?> clazz);
    public static Set<Method> getPublicMethods(Class<?> clazz, Set<String> excludedNames);
    public static boolean isMethodExcluded(Method method, Set<String> exclusions);
    public static String getSimpleMethodSignature(Method method);
}

public class DataSetAPICompletenessTest extends ScalaAPICompletenessTestBase {
    
    @Test
    public void testDataSetAPI() {
        Class<?> javaDataSet = org.apache.flink.api.java.DataSet.class;
        Class<?> scalaDataSet = org.apache.flink.api.scala.DataSet.class;
        
        // Compare APIs with standard exclusions
        compareApis(javaDataSet, scalaDataSet);
    }
    
    @Override
    protected Set<String> getExcludedMethods() {
        Set<String> excluded = new HashSet<>();
        
        // Exclude Scala-specific methods
        excluded.add("$plus$plus"); // Scala ++ operator
        excluded.add("$colon$colon"); // Scala :: operator
        
        // Exclude internal methods
        excluded.add("clean");
        excluded.add("getExecutionEnvironment");
        
        return excluded;
    }
    
    @Override
    protected boolean isExcluded(Method method) {
        // Additional custom exclusion logic
        String methodName = method.getName();
        
        // Exclude synthetic methods
        if (method.isSynthetic()) {
            return true;
        }
        
        // Exclude bridge methods
        if (method.isBridge()) {
            return true;
        }
        
        // Exclude Scala-specific naming patterns
        if (methodName.contains("$")) {
            return true;
        }
        
        return super.isExcluded(method);
    }
}

public class Tuple2ComparatorTest extends TupleComparatorTestBase<Tuple2<String, Integer>> {
    
    @Override
    public void setup() {
        javaComparator = createJavaComparator();
        scalaComparator = createScalaComparator();
    }
    
    @Test
    public void testTuple2Comparison() {
        Tuple2<String, Integer> tuple1 = new Tuple2<>("hello", 42);
        Tuple2<String, Integer> tuple2 = new Tuple2<>("world", 24);
        
        testComparatorEquality(tuple1, tuple2);
        testComparatorSerialization();
        testComparatorNormalization();
    }
    
    @Override
    protected Tuple2<String, Integer>[] getTestData() {
        return new Tuple2[]{
            new Tuple2<>("a", 1),
            new Tuple2<>("b", 2),
            new Tuple2<>("c", 3),
            new Tuple2<>("a", 1), // Duplicate for equality testing
        };
    }
    
    @Override
    protected TypeComparator<Tuple2<String, Integer>> createJavaComparator() {
        return new TupleComparator<>(
            new int[]{0, 1}, // Key positions
            new TypeComparator[]{
                new StringComparator(true),
                new IntComparator(true)
            },
            new TypeSerializer[]{
                StringSerializer.INSTANCE,
                IntSerializer.INSTANCE
            }
        );
    }
    
    @Override
    protected TypeComparator<Tuple2<String, Integer>> createScalaComparator() {
        // Create Scala equivalent comparator
        return new ScalaTupleComparator<>(
            new int[]{0, 1},
            new TypeComparator[]{
                new StringComparator(true),
                new IntComparator(true) 
            }
        );
    }
}

public class CustomAPICompletenessTest extends ScalaAPICompletenessTestBase {
    
    @Test
    public void testStreamingAPICompleteness() {
        Class<?> javaDataStream = org.apache.flink.streaming.api.datastream.DataStream.class;
        Class<?> scalaDataStream = org.apache.flink.streaming.api.scala.DataStream.class;
        
        Set<String> customExclusions = new HashSet<>();
        customExclusions.add("javaStream"); // Scala-specific bridge method
        customExclusions.add("scalaStream"); // Java-specific bridge method
        
        compareApis(javaDataStream, scalaDataStream, customExclusions);
    }
    
    @Override
    protected void compareApis(Class<?> javaClass, Class<?> scalaClass, Set<String> excludedMethods) {
        LOG.info("Comparing {} with {}", javaClass.getSimpleName(), scalaClass.getSimpleName());
        
        Set<Method> javaMethods = getFilteredMethods(javaClass, excludedMethods);
        Set<Method> scalaMethods = getFilteredMethods(scalaClass, excludedMethods);
        
        // Find methods in Java but not in Scala
        Set<String> javaSignatures = javaMethods.stream()
            .map(this::getMethodSignature)
            .collect(Collectors.toSet());
        
        Set<String> scalaSignatures = scalaMethods.stream()
            .map(this::getMethodSignature)
            .collect(Collectors.toSet());
        
        Set<String> missingInScala = new HashSet<>(javaSignatures);
        missingInScala.removeAll(scalaSignatures);
        
        Set<String> missingInJava = new HashSet<>(scalaSignatures);
        missingInJava.removeAll(javaSignatures);
        
        // Report findings
        if (!missingInScala.isEmpty()) {
            reportMissingMethods(missingInScala, "Scala API");
        }
        
        if (!missingInJava.isEmpty()) {
            reportMissingMethods(missingInJava, "Java API");
        }
        
        // Assertions
        assertTrue("Scala API missing methods: " + missingInScala, missingInScala.isEmpty());
        assertTrue("Java API has extra methods: " + missingInJava, missingInJava.isEmpty());
        
        LOG.info("API comparison successful: {} methods verified", javaSignatures.size());
    }
    
    private Set<Method> getFilteredMethods(Class<?> clazz, Set<String> excludedMethods) {
        return ReflectionTestUtils.getPublicMethods(clazz, excludedMethods);
    }
}

public class OperatorAPICompletenessTest extends ScalaAPICompletenessTestBase {
    
    @Test
    public void testAllOperatorAPIs() {
        // Test core transformation operators
        testOperatorAPI("DataSet", 
            org.apache.flink.api.java.DataSet.class,
            org.apache.flink.api.scala.DataSet.class);
            
        testOperatorAPI("DataStream",
            org.apache.flink.streaming.api.datastream.DataStream.class,
            org.apache.flink.streaming.api.scala.DataStream.class);
            
        testOperatorAPI("KeyedStream",
            org.apache.flink.streaming.api.datastream.KeyedStream.class,
            org.apache.flink.streaming.api.scala.KeyedStream.class);
    }
    
    private void testOperatorAPI(String apiName, Class<?> javaClass, Class<?> scalaClass) {
        LOG.info("Testing {} API completeness", apiName);
        
        try {
            compareApis(javaClass, scalaClass);
            LOG.info("{} API comparison successful", apiName);
        } catch (AssertionError e) {
            LOG.error("{} API comparison failed: {}", apiName, e.getMessage());
            throw new AssertionError(apiName + " API completeness test failed", e);
        }
    }
    
    @Override
    protected Set<String> getExcludedMethods() {
        Set<String> excluded = super.getExcludedMethods();
        
        // Common exclusions across all operator APIs
        excluded.add("returns"); // Type hint methods
        excluded.add("getType");
        excluded.add("getTransformation");
        
        // Scala collection interop methods
        excluded.add("asScala");
        excluded.add("asJava");
        
        return excluded;
    }
}

public class SerializationAPICompletenessTest extends ScalaAPICompletenessTestBase {
    
    @Test
    public void testSerializerAPIs() {
        compareSerializerAPIs(
            "Tuple2Serializer",
            org.apache.flink.api.common.typeutils.base.TupleSerializer.class,
            org.apache.flink.api.scala.typeutils.ScalaTupleSerializer.class
        );
    }
    
    private void compareSerializerAPIs(String serializerName, Class<?> javaClass, Class<?> scalaClass) {
        LOG.info("Comparing {} implementations", serializerName);
        
        // Get serialization-specific methods
        Set<Method> javaMethods = Arrays.stream(javaClass.getMethods())
            .filter(m -> isSerializationMethod(m))
            .collect(Collectors.toSet());
            
        Set<Method> scalaMethods = Arrays.stream(scalaClass.getMethods())
            .filter(m -> isSerializationMethod(m))
            .collect(Collectors.toSet());
        
        // Compare method signatures
        compareMethodSets(javaMethods, scalaMethods, serializerName);
    }
    
    private boolean isSerializationMethod(Method method) {
        String name = method.getName();
        return name.equals("serialize") || 
               name.equals("deserialize") ||
               name.equals("getLength") ||
               name.equals("copy");
    }
    
    private void compareMethodSets(Set<Method> javaMethods, Set<Method> scalaMethods, String context) {
        Set<String> javaSignatures = javaMethods.stream()
            .map(this::getMethodSignature)
            .collect(Collectors.toSet());
            
        Set<String> scalaSignatures = scalaMethods.stream()
            .map(this::getMethodSignature)
            .collect(Collectors.toSet());
        
        assertEquals(context + " method signatures should match", javaSignatures, scalaSignatures);
    }
}