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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 org.apache.commons.io.function;
import static org.junit.jupiter.api.Assertions.assertArrayEquals;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UncheckedIOException;
import java.util.Optional;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
import org.apache.commons.lang3.ArrayUtils;
import org.junit.jupiter.api.Test;
/**
* Tests {@link IOFunction}.
*/
public class IOFunctionTest {
private static final class Holder<T> {
T value;
}
@Test
public void testAndThenConsumer() throws IOException {
final Holder<Integer> holder = new Holder<>();
final IOFunction<InputStream, Integer> readByte = InputStream::read;
final Consumer<Integer> sinkInteger = i -> {
holder.value = i * i;
};
final IOConsumer<InputStream> productFunction = readByte.andThen(sinkInteger);
final InputStream is = new ByteArrayInputStream(new byte[] {2, 3});
productFunction.accept(is);
assertEquals(4, holder.value);
productFunction.accept(is);
assertEquals(9, holder.value);
}
@Test
public void testAndThenFunction() throws IOException {
final IOFunction<InputStream, Integer> readByte = InputStream::read;
final Function<Integer, Integer> squareInteger = i -> i * i;
final IOFunction<InputStream, Integer> productFunction = readByte.andThen(squareInteger);
final InputStream is = new ByteArrayInputStream(new byte[] {2, 3});
assertEquals(4, productFunction.apply(is));
assertEquals(9, productFunction.apply(is));
}
@Test
public void testAndThenIOConsumer() throws IOException {
final Holder<Integer> holder = new Holder<>();
final IOFunction<InputStream, Integer> readByte = InputStream::read;
final IOConsumer<Integer> sinkInteger = i -> {
holder.value = i * i;
};
final IOConsumer<InputStream> productFunction = readByte.andThen(sinkInteger);
final InputStream is = new ByteArrayInputStream(new byte[] {2, 3});
productFunction.accept(is);
assertEquals(4, holder.value);
productFunction.accept(is);
assertEquals(9, holder.value);
}
@Test
public void testAndThenIOFunction() throws IOException {
final IOFunction<InputStream, Integer> readByte = InputStream::read;
final IOFunction<Integer, Integer> squareInteger = i -> i * i;
final IOFunction<InputStream, Integer> productFunction = readByte.andThen(squareInteger);
final InputStream is = new ByteArrayInputStream(new byte[] {2, 3});
assertEquals(4, productFunction.apply(is));
assertEquals(9, productFunction.apply(is));
}
@Test
public void testApply() throws IOException {
final IOFunction<InputStream, Integer> readByte = InputStream::read;
final InputStream is = new ByteArrayInputStream(new byte[] {(byte) 0xa, (byte) 0xb, (byte) 0xc});
assertEquals(0xa, readByte.apply(is));
assertEquals(0xb, readByte.apply(is));
assertEquals(0xc, readByte.apply(is));
assertEquals(-1, readByte.apply(is));
}
@Test
public void testApplyThrowsException() {
final IOFunction<InputStream, Integer> throwException = function -> {
throw new IOException("Boom!");
};
assertThrows(IOException.class, () -> throwException.apply(new ByteArrayInputStream(ArrayUtils.EMPTY_BYTE_ARRAY)));
}
@Test
public void testAsFunction() {
assertThrows(UncheckedIOException.class, () -> Optional.of("a").map(TestConstants.THROWING_IO_FUNCTION.asFunction()).get());
assertEquals("a", Optional.of("a").map(IOFunction.identity().asFunction()).get());
}
@Test
public void testComposeFunction() throws IOException {
final Function<InputStream, Integer> alwaysSeven = is -> 7;
final IOFunction<Integer, Integer> squareInteger = i -> i * i;
final IOFunction<InputStream, Integer> productFunction = squareInteger.compose(alwaysSeven);
final InputStream is = new ByteArrayInputStream(new byte[] {2, 3});
assertEquals(49, productFunction.apply(is));
assertEquals(49, productFunction.apply(is));
}
@Test
public void testComposeIOFunction() throws IOException {
final IOFunction<InputStream, Integer> readByte = InputStream::read;
final IOFunction<Integer, Integer> squareInteger = i -> i * i;
final IOFunction<InputStream, Integer> productFunction = squareInteger.compose(readByte);
final InputStream is = new ByteArrayInputStream(new byte[] {2, 3});
assertEquals(4, productFunction.apply(is));
assertEquals(9, productFunction.apply(is));
}
@Test
public void testComposeIOSupplier() throws IOException {
final InputStream is = new ByteArrayInputStream(new byte[] {2, 3});
final IOSupplier<Integer> readByte = is::read;
final IOFunction<Integer, Integer> squareInteger = i -> i * i;
final IOSupplier<Integer> productFunction = squareInteger.compose(readByte);
assertEquals(4, productFunction.get());
assertEquals(9, productFunction.get());
}
@Test
public void testComposeSupplier() throws IOException {
final Supplier<Integer> alwaysNine = () -> 9;
final IOFunction<Integer, Integer> squareInteger = i -> i * i;
final IOSupplier<Integer> productFunction = squareInteger.compose(alwaysNine);
assertEquals(81, productFunction.get());
assertEquals(81, productFunction.get());
}
@Test
public void testIdentity() throws IOException {
assertEquals(IOFunction.identity(), IOFunction.identity());
final IOFunction<byte[], byte[]> identityFunction = IOFunction.identity();
final byte[] buf = {(byte) 0xa, (byte) 0xb, (byte) 0xc};
assertEquals(buf, identityFunction.apply(buf));
assertArrayEquals(buf, identityFunction.apply(buf));
}
}
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