Examples with Collectors.toSet java8.util.stream.Collectors.toSet used on opensource projects

Example 1 with Collectors.toSet

use of java8.util.stream.Collectors.toSet in project streamsupport by stefan-zobel.

the class CompletableFutureTest method testMinimalCompletionStage_minimality.

/**
 * Minimal completion stages throw UOE for most non-CompletionStage methods
 */
public void testMinimalCompletionStage_minimality() {
    if (!testImplementationDetails)
        return;
    Function<Method, String> toSignature = method -> method.getName() + Arrays.toString(method.getParameterTypes());
    Predicate<Method> isNotStatic = method -> (method.getModifiers() & Modifier.STATIC) == 0;
    List<Method> minimalMethods = RefStreams.of(Object.class, CompletionStage.class).flatMap(klazz -> RefStreams.of(klazz.getMethods())).filter(isNotStatic).collect(Collectors.toList());
    // Methods from CompletableFuture permitted NOT to throw UOE
    String[] signatureWhitelist = { "newIncompleteFuture[]", "defaultExecutor[]", "minimalCompletionStage[]", "copy[]" };
    Set<String> permittedMethodSignatures = RefStreams.concat(StreamSupport.stream(minimalMethods).map(toSignature), RefStreams.of(signatureWhitelist)).collect(Collectors.toSet());
    List<Method> allMethods = RefStreams.of(CompletableFuture.class.getMethods()).filter(isNotStatic).filter(method -> !permittedMethodSignatures.contains(toSignature.apply(method))).collect(Collectors.toList());
    List<CompletionStage<Integer>> stages = new ArrayList<CompletionStage<Integer>>();
    CompletionStage<Integer> min = new CompletableFuture<Integer>().minimalCompletionStage();
    stages.add(min);
    stages.add(min.thenApply(x -> x));
    stages.add(CompletableFuture.completedStage(1));
    stages.add(CompletableFuture.failedStage(new CFException()));
    List<Method> bugs = new ArrayList<>();
    for (Method method : allMethods) {
        Class<?>[] parameterTypes = method.getParameterTypes();
        Object[] args = new Object[parameterTypes.length];
        // Manufacture boxed primitives for primitive params
        for (int i = 0; i < args.length; i++) {
            Class<?> type = parameterTypes[i];
            if (type == boolean.class)
                args[i] = false;
            else if (type == int.class)
                args[i] = 0;
            else if (type == long.class)
                args[i] = 0L;
        }
        for (CompletionStage<Integer> stage : stages) {
            try {
                method.invoke(stage, args);
                bugs.add(method);
            } catch (java.lang.reflect.InvocationTargetException expected) {
                if (!(expected.getCause() instanceof UnsupportedOperationException)) {
                    bugs.add(method);
                // expected.getCause().printStackTrace();
                }
            } catch (Exception bad) {
                throw new Error(bad);
            }
        }
    }
    if (!bugs.isEmpty())
        throw new Error("Methods did not throw UOE: " + bugs);
}