ObservableNullTests.java

/**
 * Copyright (c) 2016-present, RxJava Contributors.
 *
 * 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.reactivex.observable;

import java.lang.reflect.*;
import java.util.*;
import java.util.concurrent.*;

import org.junit.*;

import io.reactivex.*;
import io.reactivex.Observable;
import io.reactivex.Observer;
import io.reactivex.disposables.Disposable;
import io.reactivex.exceptions.TestException;
import io.reactivex.functions.*;
import io.reactivex.internal.functions.Functions;
import io.reactivex.observers.TestObserver;
import io.reactivex.schedulers.Schedulers;

/**
 * Verifies the operators handle null values properly by emitting/throwing NullPointerExceptions.
 */
public class ObservableNullTests {

    Observable<Integer> just1 = Observable.just(1);

    //***********************************************************
    // Static methods
    //***********************************************************

    @Test(expected = NullPointerException.class)
    public void ambVarargsNull() {
        Observable.ambArray((Observable<Object>[])null);
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void ambVarargsOneIsNull() {
        Observable.ambArray(Observable.never(), null).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void ambIterableNull() {
        Observable.amb((Iterable<Observable<Object>>)null);
    }

    @Test
    public void ambIterableIteratorNull() {
        Observable.amb(new Iterable<Observable<Object>>() {
            @Override
            public Iterator<Observable<Object>> iterator() {
                return null;
            }
        }).test().assertError(NullPointerException.class);
    }

    @SuppressWarnings("unchecked")
    @Test
    public void ambIterableOneIsNull() {
        Observable.amb(Arrays.asList(Observable.never(), null))
                .test()
                .assertError(NullPointerException.class);
    }

    @Test(expected = NullPointerException.class)
    public void combineLatestVarargsNull() {
        Observable.combineLatest(new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        }, 128, (Observable<Object>[])null);
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void combineLatestVarargsOneIsNull() {
        Observable.combineLatest(new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        }, 128, Observable.never(), null).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void combineLatestIterableNull() {
        Observable.combineLatest((Iterable<Observable<Object>>)null, new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        }, 128);
    }

    @Test(expected = NullPointerException.class)
    public void combineLatestIterableIteratorNull() {
        Observable.combineLatest(new Iterable<Observable<Object>>() {
            @Override
            public Iterator<Observable<Object>> iterator() {
                return null;
            }
        }, new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        }, 128).blockingLast();
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void combineLatestIterableOneIsNull() {
        Observable.combineLatest(Arrays.asList(Observable.never(), null), new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        }, 128).blockingLast();
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void combineLatestVarargsFunctionNull() {
        Observable.combineLatest(null, 128, Observable.never());
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void combineLatestVarargsFunctionReturnsNull() {
        Observable.combineLatest(new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return null;
            }
        }, 128, just1).blockingLast();
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void combineLatestIterableFunctionNull() {
        Observable.combineLatest(Arrays.asList(just1), null, 128);
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void combineLatestIterableFunctionReturnsNull() {
        Observable.combineLatest(Arrays.asList(just1), new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return null;
            }
        }, 128).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void combineLatestDelayErrorVarargsNull() {
        Observable.combineLatestDelayError(new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        }, 128, (Observable<Object>[])null);
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void combineLatestDelayErrorVarargsOneIsNull() {
        Observable.combineLatestDelayError(new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        }, 128, Observable.never(), null).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void combineLatestDelayErrorIterableNull() {
        Observable.combineLatestDelayError((Iterable<Observable<Object>>)null, new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        }, 128);
    }

    @Test(expected = NullPointerException.class)
    public void combineLatestDelayErrorIterableIteratorNull() {
        Observable.combineLatestDelayError(new Iterable<Observable<Object>>() {
            @Override
            public Iterator<Observable<Object>> iterator() {
                return null;
            }
        }, new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        }, 128).blockingLast();
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void combineLatestDelayErrorIterableOneIsNull() {
        Observable.combineLatestDelayError(Arrays.asList(Observable.never(), null), new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        }, 128).blockingLast();
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void combineLatestDelayErrorVarargsFunctionNull() {
        Observable.combineLatestDelayError(null, 128, Observable.never());
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void combineLatestDelayErrorVarargsFunctionReturnsNull() {
        Observable.combineLatestDelayError(new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return null;
            }
        }, 128, just1).blockingLast();
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void combineLatestDelayErrorIterableFunctionNull() {
        Observable.combineLatestDelayError(Arrays.asList(just1), null, 128);
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void combineLatestDelayErrorIterableFunctionReturnsNull() {
        Observable.combineLatestDelayError(Arrays.asList(just1), new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return null;
            }
        }, 128).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void concatIterableNull() {
        Observable.concat((Iterable<Observable<Object>>)null);
    }

    @Test(expected = NullPointerException.class)
    public void concatIterableIteratorNull() {
        Observable.concat(new Iterable<Observable<Object>>() {
            @Override
            public Iterator<Observable<Object>> iterator() {
                return null;
            }
        }).blockingLast();
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void concatIterableOneIsNull() {
        Observable.concat(Arrays.asList(just1, null)).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void concatObservableNull() {
        Observable.concat((Observable<Observable<Object>>)null);
    }

    @Test(expected = NullPointerException.class)
    public void concatArrayNull() {
        Observable.concatArray((Observable<Object>[])null);
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void concatArrayOneIsNull() {
        Observable.concatArray(just1, null).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void createNull() {
        Observable.unsafeCreate(null);
    }

    @Test(expected = NullPointerException.class)
    public void deferFunctionNull() {
        Observable.defer(null);
    }

    @Test(expected = NullPointerException.class)
    public void deferFunctionReturnsNull() {
        Observable.defer(new Callable<Observable<Object>>() {
            @Override
            public Observable<Object> call() {
                return null;
            }
        }).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void errorFunctionNull() {
        Observable.error((Callable<Throwable>)null);
    }

    @Test(expected = NullPointerException.class)
    public void errorFunctionReturnsNull() {
        Observable.error(new Callable<Throwable>() {
            @Override
            public Throwable call() {
                return null;
            }
        }).blockingSubscribe();
    }

    @Test(expected = NullPointerException.class)
    public void errorThrowableNull() {
        Observable.error((Throwable)null);
    }

    @Test(expected = NullPointerException.class)
    public void fromArrayNull() {
        Observable.fromArray((Object[])null);
    }

    @Test(expected = NullPointerException.class)
    public void fromArrayOneIsNull() {
        Observable.fromArray(1, null).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void fromCallableNull() {
        Observable.fromCallable(null);
    }

    @Test(expected = NullPointerException.class)
    public void fromCallableReturnsNull() {
        Observable.fromCallable(new Callable<Object>() {
            @Override
            public Object call() throws Exception {
                return null;
            }
        }).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void fromFutureNull() {
        Observable.fromFuture(null);
    }

    @Test
    public void fromFutureReturnsNull() {
        FutureTask<Object> f = new FutureTask<Object>(Functions.EMPTY_RUNNABLE, null);
        f.run();

        TestObserver<Object> ts = new TestObserver<Object>();
        Observable.fromFuture(f).subscribe(ts);
        ts.assertNoValues();
        ts.assertNotComplete();
        ts.assertError(NullPointerException.class);
    }

    @Test(expected = NullPointerException.class)
    public void fromFutureTimedFutureNull() {
        Observable.fromFuture(null, 1, TimeUnit.SECONDS);
    }

    @Test(expected = NullPointerException.class)
    public void fromFutureTimedUnitNull() {
        Observable.fromFuture(new FutureTask<Object>(Functions.EMPTY_RUNNABLE, null), 1, null);
    }

    @Test(expected = NullPointerException.class)
    public void fromFutureTimedSchedulerNull() {
        Observable.fromFuture(new FutureTask<Object>(Functions.EMPTY_RUNNABLE, null), 1, TimeUnit.SECONDS, null);
    }

    @Test(expected = NullPointerException.class)
    public void fromFutureTimedReturnsNull() {
        FutureTask<Object> f = new FutureTask<Object>(Functions.EMPTY_RUNNABLE, null);
        f.run();
        Observable.fromFuture(f, 1, TimeUnit.SECONDS).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void fromFutureSchedulerNull() {
        FutureTask<Object> f = new FutureTask<Object>(Functions.EMPTY_RUNNABLE, null);
        Observable.fromFuture(f, null);
    }

    @Test(expected = NullPointerException.class)
    public void fromIterableNull() {
        Observable.fromIterable(null);
    }

    @Test(expected = NullPointerException.class)
    public void fromIterableIteratorNull() {
        Observable.fromIterable(new Iterable<Object>() {
            @Override
            public Iterator<Object> iterator() {
                return null;
            }
        }).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void fromIterableValueNull() {
        Observable.fromIterable(Arrays.asList(1, null)).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void generateConsumerNull() {
        Observable.generate(null);
    }

    @Test(expected = NullPointerException.class)
    public void generateConsumerEmitsNull() {
        Observable.generate(new Consumer<Emitter<Object>>() {
            @Override
            public void accept(Emitter<Object> s) {
                s.onNext(null);
            }
        }).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void generateStateConsumerInitialStateNull() {
        BiConsumer<Integer, Emitter<Integer>> generator = new BiConsumer<Integer, Emitter<Integer>>() {
            @Override
            public void accept(Integer s, Emitter<Integer> o) {
                o.onNext(1);
            }
        };
        Observable.generate(null, generator);
    }

    @Test(expected = NullPointerException.class)
    public void generateStateFunctionInitialStateNull() {
        Observable.generate(null, new BiFunction<Object, Emitter<Object>, Object>() {
            @Override
            public Object apply(Object s, Emitter<Object> o) { o.onNext(1); return s; }
        });
    }

    @Test(expected = NullPointerException.class)
    public void generateStateConsumerNull() {
        Observable.generate(new Callable<Integer>() {
            @Override
            public Integer call() {
                return 1;
            }
        }, (BiConsumer<Integer, Emitter<Object>>)null);
    }

    @Test
    public void generateConsumerStateNullAllowed() {
        BiConsumer<Integer, Emitter<Integer>> generator = new BiConsumer<Integer, Emitter<Integer>>() {
            @Override
            public void accept(Integer s, Emitter<Integer> o) {
                o.onComplete();
            }
        };
        Observable.generate(new Callable<Integer>() {
            @Override
            public Integer call() {
                return null;
            }
        }, generator).blockingSubscribe();
    }

    @Test
    public void generateFunctionStateNullAllowed() {
        Observable.generate(new Callable<Object>() {
            @Override
            public Object call() {
                return null;
            }
        }, new BiFunction<Object, Emitter<Object>, Object>() {
            @Override
            public Object apply(Object s, Emitter<Object> o) { o.onComplete(); return s; }
        }).blockingSubscribe();
    }

    @Test(expected = NullPointerException.class)
    public void generateConsumerDisposeNull() {
        BiConsumer<Integer, Emitter<Integer>> generator = new BiConsumer<Integer, Emitter<Integer>>() {
            @Override
            public void accept(Integer s, Emitter<Integer> o) {
                o.onNext(1);
            }
        };
        Observable.generate(new Callable<Integer>() {
            @Override
            public Integer call() {
                return 1;
            }
        }, generator, null);
    }

    @Test(expected = NullPointerException.class)
    public void generateFunctionDisposeNull() {
        Observable.generate(new Callable<Object>() {
            @Override
            public Object call() {
                return 1;
            }
        }, new BiFunction<Object, Emitter<Object>, Object>() {
            @Override
            public Object apply(Object s, Emitter<Object> o) { o.onNext(1); return s; }
        }, null);
    }

    @Test(expected = NullPointerException.class)
    public void intervalUnitNull() {
        Observable.interval(1, null);
    }

    public void intervalSchedulerNull() {
        Observable.interval(1, TimeUnit.SECONDS, null);
    }

    @Test(expected = NullPointerException.class)
    public void intervalPeriodUnitNull() {
        Observable.interval(1, 1, null);
    }

    @Test(expected = NullPointerException.class)
    public void intervalPeriodSchedulerNull() {
        Observable.interval(1, 1, TimeUnit.SECONDS, null);
    }

    @Test(expected = NullPointerException.class)
    public void intervalRangeUnitNull() {
        Observable.intervalRange(1,1, 1, 1, null);
    }

    @Test(expected = NullPointerException.class)
    public void intervalRangeSchedulerNull() {
        Observable.intervalRange(1, 1, 1, 1, TimeUnit.SECONDS, null);
    }

    @Test
    public void justNull() throws Exception {
        @SuppressWarnings("rawtypes")
        Class<Observable> clazz = Observable.class;
        for (int argCount = 1; argCount < 10; argCount++) {
            for (int argNull = 1; argNull <= argCount; argNull++) {
                Class<?>[] params = new Class[argCount];
                Arrays.fill(params, Object.class);

                Object[] values = new Object[argCount];
                Arrays.fill(values, 1);
                values[argNull - 1] = null;

                Method m = clazz.getMethod("just", params);

                try {
                    m.invoke(null, values);
                    Assert.fail("No exception for argCount " + argCount + " / argNull " + argNull);
                } catch (InvocationTargetException ex) {
                    if (!(ex.getCause() instanceof NullPointerException)) {
                        Assert.fail("Unexpected exception for argCount " + argCount + " / argNull " + argNull + ": " + ex);
                    }
                }
            }
        }
    }

    @Test(expected = NullPointerException.class)
    public void mergeIterableNull() {
        Observable.merge((Iterable<Observable<Object>>)null, 128, 128);
    }

    @Test(expected = NullPointerException.class)
    public void mergeIterableIteratorNull() {
        Observable.merge(new Iterable<Observable<Object>>() {
            @Override
            public Iterator<Observable<Object>> iterator() {
                return null;
            }
        }, 128, 128).blockingLast();
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void mergeIterableOneIsNull() {
        Observable.merge(Arrays.asList(just1, null), 128, 128).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void mergeArrayNull() {
        Observable.mergeArray(128, 128, (Observable<Object>[])null);
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void mergeArrayOneIsNull() {
        Observable.mergeArray(128, 128, just1, null).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void mergeDelayErrorIterableNull() {
        Observable.mergeDelayError((Iterable<Observable<Object>>)null, 128, 128);
    }

    @Test(expected = NullPointerException.class)
    public void mergeDelayErrorIterableIteratorNull() {
        Observable.mergeDelayError(new Iterable<Observable<Object>>() {
            @Override
            public Iterator<Observable<Object>> iterator() {
                return null;
            }
        }, 128, 128).blockingLast();
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void mergeDelayErrorIterableOneIsNull() {
        Observable.mergeDelayError(Arrays.asList(just1, null), 128, 128).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void mergeDelayErrorArrayNull() {
        Observable.mergeArrayDelayError(128, 128, (Observable<Object>[])null);
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void mergeDelayErrorArrayOneIsNull() {
        Observable.mergeArrayDelayError(128, 128, just1, null).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void sequenceEqualFirstNull() {
        Observable.sequenceEqual(null, just1);
    }

    @Test(expected = NullPointerException.class)
    public void sequenceEqualSecondNull() {
        Observable.sequenceEqual(just1, null);
    }

    @Test(expected = NullPointerException.class)
    public void sequenceEqualComparatorNull() {
        Observable.sequenceEqual(just1, just1, null);
    }

    @Test(expected = NullPointerException.class)
    public void switchOnNextNull() {
        Observable.switchOnNext(null);
    }

    @Test(expected = NullPointerException.class)
    public void timerUnitNull() {
        Observable.timer(1, null);
    }

    @Test(expected = NullPointerException.class)
    public void timerSchedulerNull() {
        Observable.timer(1, TimeUnit.SECONDS, null);
    }

    @Test(expected = NullPointerException.class)
    public void usingResourceSupplierNull() {
        Observable.using(null, new Function<Object, Observable<Integer>>() {
            @Override
            public Observable<Integer> apply(Object d) {
                return just1;
            }
        }, new Consumer<Object>() {
            @Override
            public void accept(Object d) { }
        });
    }

    @Test(expected = NullPointerException.class)
    public void usingObservableSupplierNull() {
        Observable.using(new Callable<Object>() {
            @Override
            public Object call() {
                return 1;
            }
        }, null, new Consumer<Object>() {
            @Override
            public void accept(Object d) { }
        });
    }

    @Test(expected = NullPointerException.class)
    public void usingObservableSupplierReturnsNull() {
        Observable.using(new Callable<Object>() {
            @Override
            public Object call() {
                return 1;
            }
        }, new Function<Object, Observable<Object>>() {
            @Override
            public Observable<Object> apply(Object d) {
                return null;
            }
        }, new Consumer<Object>() {
            @Override
            public void accept(Object d) { }
        }).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void usingDisposeNull() {
        Observable.using(new Callable<Object>() {
            @Override
            public Object call() {
                return 1;
            }
        }, new Function<Object, Observable<Integer>>() {
            @Override
            public Observable<Integer> apply(Object d) {
                return just1;
            }
        }, null);
    }

    @Test(expected = NullPointerException.class)
    public void zipIterableNull() {
        Observable.zip((Iterable<Observable<Object>>)null, new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        });
    }

    @Test(expected = NullPointerException.class)
    public void zipIterableIteratorNull() {
        Observable.zip(new Iterable<Observable<Object>>() {
            @Override
            public Iterator<Observable<Object>> iterator() {
                return null;
            }
        }, new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] v) {
                return 1;
            }
        }).blockingLast();
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void zipIterableFunctionNull() {
        Observable.zip(Arrays.asList(just1, just1), null);
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void zipIterableFunctionReturnsNull() {
        Observable.zip(Arrays.asList(just1, just1), new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] a) {
                return null;
            }
        }).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void zipObservableNull() {
        Observable.zip((Observable<Observable<Object>>)null, new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] a) {
                return 1;
            }
        });
    }

    @Test(expected = NullPointerException.class)
    public void zipObservableFunctionNull() {
        Observable.zip((Observable.just(just1)), null);
    }

    @Test(expected = NullPointerException.class)
    public void zipObservableFunctionReturnsNull() {
        Observable.zip((Observable.just(just1)), new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] a) {
                return null;
            }
        }).blockingLast();
    }

    @Test(expected = NullPointerException.class)
    public void zipIterable2Null() {
        Observable.zipIterable((Iterable<Observable<Object>>)null, new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] a) {
                return 1;
            }
        }, true, 128);
    }

    @Test(expected = NullPointerException.class)
    public void zipIterable2IteratorNull() {
        Observable.zipIterable(new Iterable<Observable<Object>>() {
            @Override
            public Iterator<Observable<Object>> iterator() {
                return null;
            }
        }, new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] a) {
                return 1;
            }
        }, true, 128).blockingLast();
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void zipIterable2FunctionNull() {
        Observable.zipIterable(Arrays.asList(just1, just1), null, true, 128);
    }

    @SuppressWarnings("unchecked")
    @Test(expected = NullPointerException.class)
    public void zipIterable2FunctionReturnsNull() {
        Observable.zipIterable(Arrays.asList(just1, just1), new Function<Object[], Object>() {
            @Override
            public Object apply(Object[] a) {
                return null;
            }
        }, true, 128).blockingLast();
    }

    //*************************************************************
    // Instance methods
    //*************************************************************

    @Test(expected = NullPointerException.class)
    public void allPredicateNull() {
        just1.all(null);
    }

    @Test(expected = NullPointerException.class)
    public void ambWithNull() {
        just1.ambWith(null);
    }

    @Test(expected = NullPointerException.class)
    public void anyPredicateNull() {
        just1.any(null);
    }

    @Test(expected = NullPointerException.class)
    public void bufferSupplierNull() {
        just1.buffer(1, 1, (Callable<List<Integer>>)null);
    }

    @Test(expected = NullPointerException.class)
    public void bufferSupplierReturnsNull() {
        just1.buffer(1, 1, new Callable<Collection<Integer>>() {
            @Override
            public Collection<Integer> call() {
                return null;
            }
        }).blockingSubscribe();
    }

    @Test(expected = NullPointerException.class)
    public void bufferTimedUnitNull() {
        just1.buffer(1L, 1L, null);
    }

    @Test(expected = NullPointerException.class)
    public void bufferTimedSchedulerNull() {
        just1.buffer(1L, 1L, TimeUnit.SECONDS, null);
    }

    @Test(expected = NullPointerException.class)
    public void bufferTimedSupplierNull() {
        just1.buffer(1L, 1L, TimeUnit.SECONDS, Schedulers.single(), null);
    }

    @Test(expected = NullPointerException.class)
    public void bufferTimedSupplierReturnsNull() {
        just1.buffer(1L, 1L, TimeUnit.SECONDS, Schedulers.single(), new Callable<Collection<Integer>>() {
            @Override
            public Collection<Integer> call() {
                return null;
            }
        }).blockingSubscribe();
    }

    @Test(expected = NullPointerException.class)
    public void bufferOpenCloseOpenNull() {
        just1.buffer(null, new Function<Object, Observable<Integer>>() {
            @Override
            public Observable<Integer> apply(Object o) {
                return just1;
            }
        });
    }

    @Test(expected = NullPointerException.class)
    public void bufferOpenCloseCloseNull() {
        just1.buffer(just1, (Function<Integer, Observable<Object>>)null);
    }

    @Test(expected = NullPointerException.class)
    public void bufferOpenCloseCloseReturnsNull() {
        just1.buffer(just1, new Function<Integer, Observable<Object>>() {
            @Override
            public Observable<Object> apply(Integer v) {
                return null;
            }
        }).blockingSubscribe();
    }

    @Test(expected = NullPointerException.class)
    public void bufferBoundaryNull() {
        just1.buffer((Observable<Object>)null);
    }

    @Test(expected = NullPointerException.class)
    public void bufferBoundarySupplierNull() {
        just1.buffer(just1, (Callable<List<Integer>>)null);
    }

    @Test(expected = NullPointerException.class)
    public void bufferBoundarySupplierReturnsNull() {
        just1.buffer(just1, new Callable<Collection<Integer>>() {
            @Override
            public Collection<Integer> call() {
                return null;
            }
        }).blockingSubscribe();
    }

    @Test(expected = NullPointerException.class)
    public void bufferBoundarySupplier2Null() {
        just1.buffer((Callable<Observable<Integer>>)null);
    }

    @Test(expected = NullPointerException.class)
    public void bufferBoundarySupplier2ReturnsNull() {
        just1.buffer(new Callable<Observable<Object>>() {
            @Override
            public Observable<Object> call() {
                return null;
            }
        }).blockingSubscribe();
    }

    @Test(expected = NullPointerException.class)
    public void bufferBoundarySupplier2SupplierNull() {
        just1.buffer(new Callable<Observable<Integer>>() {
            @Override
            public Observable<Integer> call() {
                return just1;
            }
        }, null);
    }

    @Test(expected = NullPointerException.class)
    public void bufferBoundarySupplier2SupplierReturnsNull() {
        just1.buffer(new Callable<Observable<Integer>>() {
            @Override
            public Observable<Integer> call() {
                return just1;
            }
        }, new Callable<Collection<Integer>>() {
            @Override
            public Collection<Integer> call() {
                return null;
            }
        }).blockingSubscribe();
    }

    @Test(expected = NullPointerException.class)
    public void castNull() {
        just1.cast(null);
    }

    @Test(expected = NullPointerException.class)
    public void collectInitialSupplierNull() {
        just1.collect((Callable<Integer>)null, new BiConsumer<Integer, Integer>() {
            @Override
            public void accept(Integer a, Integer b) { }
        });