EspressoOptional.java
/*
* Copyright (C) 2018 The Android Open Source Project
*
* 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 androidx.test.espresso.util;
import static androidx.test.internal.util.Checks.checkNotNull;
import androidx.annotation.Nullable;
import androidx.test.espresso.core.internal.deps.guava.base.Function;
import androidx.test.espresso.core.internal.deps.guava.base.Optional;
import androidx.test.espresso.core.internal.deps.guava.base.Supplier;
import java.util.Set;
import kotlin.collections.SetsKt;
/**
* This class is a reimplementation of {@link com.google.common.base.Optional} to maintain API
* compatibility with older versions of espresso.
*
* @param <T> the type of instance that can be contained. {@code Optional} is naturally covariant on
* this type, so it is safe to cast an {@code Optional<T>} to {@code Optional<S>} for any
* supertype {@code S} of {@code T}.
* @see com.google.common.base.Optional
* @deprecated use androidx.annotation.Nullable/NonNull instead
*/
@Deprecated
public final class EspressoOptional<T> {
private static final EspressoOptional ABSENT = new EspressoOptional<>(null);
@Nullable private final T value;
public static <T> EspressoOptional<T> of(T reference) {
return new EspressoOptional<>(checkNotNull(reference));
}
public static <T> EspressoOptional<T> absent() {
return ABSENT;
}
public static <T> EspressoOptional<T> fromNullable(T nullableReference) {
return new EspressoOptional<>(nullableReference);
}
private EspressoOptional(@Nullable T value) {
this.value = value;
}
public boolean isPresent() {
return value != null;
}
public T get() {
return checkNotNull(value);
}
public Optional<T> or(Optional<? extends T> secondChoice) {
return isPresent() ? Optional.of(value) : (Optional<T>) secondChoice;
}
public T or(Supplier<? extends T> supplier) {
return isPresent() ? value : supplier.get();
}
public T or(T defaultValue) {
return isPresent() ? value : defaultValue;
}
public T orNull() {
return isPresent() ? value : null;
}
public Set<T> asSet() {
return isPresent() ? SetsKt.setOf(value) : SetsKt.emptySet();
}
@Override
public boolean equals(Object object) {
if (object instanceof EspressoOptional) {
EspressoOptional<?> other = (EspressoOptional<?>) object;
if (isPresent()) {
return value.equals(other.get());
} else if (!other.isPresent()) {
return true;
}
}
return false;
}
@Override
public int hashCode() {
// copy the guava implementation
return isPresent() ? 0x598df91c + value.hashCode() : 0x79a31aac;
}
@Override
public String toString() {
return isPresent() ? value.toString() : "null";
}
public <V> Optional<V> transform(Function<? super T, V> function) {
return Optional.fromNullable(value).transform(function);
}
public static <T> Iterable<T> presentInstances(
final Iterable<? extends Optional<? extends T>> optionals) {
return Optional.presentInstances(optionals);
}
private static final long serialVersionUID = 0;
}