2.x: reflection-based parameter validator & fixes

src/main/java/io/reactivex/Completable.java

@@ -929,6 +929,7 @@ public final void blockingAwait() {
     @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final boolean blockingAwait(long timeout, TimeUnit unit) {
+        ObjectHelper.requireNonNull(unit, "unit is null");
         BlockingMultiObserver<Void> observer = new BlockingMultiObserver<Void>();
         subscribe(observer);
         return observer.blockingAwait(timeout, unit);

src/main/java/io/reactivex/Maybe.java

@@ -827,6 +827,8 @@ public static <T> Flowable<T> merge(Publisher<? extends MaybeSource<? extends T>
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "unchecked", "rawtypes" })
     public static <T> Flowable<T> merge(Publisher<? extends MaybeSource<? extends T>> sources, int maxConcurrency) {
+        ObjectHelper.requireNonNull(sources, "source is null");
+        ObjectHelper.verifyPositive(maxConcurrency, "maxConcurrency");
         return RxJavaPlugins.onAssembly(new FlowableFlatMapPublisher(sources, MaybeToPublisher.instance(), false, maxConcurrency, Flowable.bufferSize()));
     }
 
@@ -852,6 +854,7 @@ public static <T> Flowable<T> merge(Publisher<? extends MaybeSource<? extends T>
     @SchedulerSupport(SchedulerSupport.NONE)
     @SuppressWarnings({ "unchecked", "rawtypes" })
     public static <T> Maybe<T> merge(MaybeSource<? extends MaybeSource<? extends T>> source) {
+        ObjectHelper.requireNonNull(source, "source is null");
         return RxJavaPlugins.onAssembly(new MaybeFlatten(source, Functions.identity()));
     }
 
@@ -1028,6 +1031,9 @@ public static <T> Flowable<T> mergeArray(MaybeSource<? extends T>... sources) {
     @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Flowable<T> mergeArrayDelayError(MaybeSource<? extends T>... sources) {
+        if (sources.length == 0) {
+            return Flowable.empty();
+        }
         return Flowable.fromArray(sources).flatMap((Function)MaybeToPublisher.instance(), true, sources.length);
     }
 
@@ -1309,6 +1315,9 @@ public static <T> Single<Boolean> sequenceEqual(MaybeSource<? extends T> source1
     @SchedulerSupport(SchedulerSupport.NONE)
     public static <T> Single<Boolean> sequenceEqual(MaybeSource<? extends T> source1, MaybeSource<? extends T> source2,
             BiPredicate<? super T, ? super T> isEqual) {
+        ObjectHelper.requireNonNull(source1, "source1 is null");
+        ObjectHelper.requireNonNull(source2, "source2 is null");
+        ObjectHelper.requireNonNull(isEqual, "isEqual is null");
         return RxJavaPlugins.onAssembly(new MaybeEqualSingle<T>(source1, source2, isEqual));
     }
 
@@ -2281,6 +2290,7 @@ public final Maybe<T> delay(long delay, TimeUnit unit, Scheduler scheduler) {
     @SchedulerSupport(SchedulerSupport.NONE)
     @BackpressureSupport(BackpressureKind.UNBOUNDED_IN)
     public final <U, V> Maybe<T> delay(Publisher<U> delayIndicator) {
+        ObjectHelper.requireNonNull(delayIndicator, "delayIndicator is null");
         return RxJavaPlugins.onAssembly(new MaybeDelayOtherPublisher<T, U>(this, delayIndicator));
     }
 
@@ -2677,6 +2687,8 @@ public final <R> Maybe<R> flatMap(
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U, R> Maybe<R> flatMap(Function<? super T, ? extends MaybeSource<? extends U>> mapper,
             BiFunction<? super T, ? super U, ? extends R> resultSelector) {
+        ObjectHelper.requireNonNull(mapper, "mapper is null");
+        ObjectHelper.requireNonNull(resultSelector, "resultSelector is null");
         return RxJavaPlugins.onAssembly(new MaybeFlatMapBiSelector<T, U, R>(this, mapper, resultSelector));
     }
 
@@ -2704,6 +2716,7 @@ public final <U, R> Maybe<R> flatMap(Function<? super T, ? extends MaybeSource<?
     @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<U> flattenAsFlowable(final Function<? super T, ? extends Iterable<? extends U>> mapper) {
+        ObjectHelper.requireNonNull(mapper, "mapper is null");
         return RxJavaPlugins.onAssembly(new MaybeFlatMapIterableFlowable<T, U>(this, mapper));
     }
 
@@ -2727,6 +2740,7 @@ public final <U> Flowable<U> flattenAsFlowable(final Function<? super T, ? exten
     @CheckReturnValue
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Observable<U> flattenAsObservable(final Function<? super T, ? extends Iterable<? extends U>> mapper) {
+        ObjectHelper.requireNonNull(mapper, "mapper is null");
         return RxJavaPlugins.onAssembly(new MaybeFlatMapIterableObservable<T, U>(this, mapper));
     }
 
@@ -3691,6 +3705,9 @@ public final Disposable subscribe(Consumer<? super T> onSuccess, Consumer<? supe
     @SchedulerSupport(SchedulerSupport.NONE)
     public final Disposable subscribe(Consumer<? super T> onSuccess, Consumer<? super Throwable> onError,
             Action onComplete) {
+        ObjectHelper.requireNonNull(onSuccess, "onSuccess is null");
+        ObjectHelper.requireNonNull(onError, "onError is null");
+        ObjectHelper.requireNonNull(onComplete, "onComplete is null");
         return subscribeWith(new MaybeCallbackObserver<T>(onSuccess, onError, onComplete));
     }