jdk/test/java/util/Optional/Basic.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 /* @test
  * @summary Basic functional test of Optional
  * @author Mike Duigou
  * @run testng Basic
  */

 import java.lang.AssertionError;
 import java.lang.NullPointerException;
 import java.lang.Throwable;
 import java.util.NoSuchElementException;
 import java.util.Optional;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.stream.Stream;

 import static org.testng.Assert.*;
 import org.testng.annotations.Test;


 public class Basic {

     @Test(groups = "unit")
     public void testEmpty() {
         Optional<Boolean> empty = Optional.empty();
         Optional<String> presentEmptyString = Optional.of("");
         Optional<Boolean> present = Optional.of(Boolean.TRUE);

         // empty
         assertTrue(empty.equals(empty));
         assertTrue(empty.equals(Optional.empty()));
         assertTrue(!empty.equals(present));
         assertTrue(0 == empty.hashCode());
         assertTrue(!empty.toString().isEmpty());
         assertTrue(!empty.toString().equals(presentEmptyString.toString()));
         assertTrue(!empty.isPresent());

         empty.ifPresent(v -> fail());

         AtomicBoolean emptyCheck = new AtomicBoolean();
         empty.ifPresentOrElse(v -> fail(), () -> emptyCheck.set(true));
         assertTrue(emptyCheck.get());

         try {
             empty.ifPresentOrElse(v -> fail(), () -> { throw new ObscureException(); });
             fail();
         } catch (ObscureException expected) {
         } catch (AssertionError e) {
             throw e;
         } catch (Throwable t) {
             fail();
         }

         assertSame(null, empty.orElse(null));
         RuntimeException orElse = new RuntimeException() { };
         assertSame(Boolean.FALSE, empty.orElse(Boolean.FALSE));
         assertSame(null, empty.orElseGet(() -> null));
         assertSame(Boolean.FALSE, empty.orElseGet(() -> Boolean.FALSE));
     }

     @Test(groups = "unit")
     public void testIfPresentAndOrElseAndNull() {
         Optional<Boolean> empty = Optional.empty();
         Optional<Boolean> present = Optional.of(Boolean.TRUE);

         // No NPE
         present.ifPresentOrElse(v -> {}, null);
         empty.ifPresent(null);
         empty.ifPresentOrElse(null, () -> {});

         // NPE
         try {
             present.ifPresent(null);
             fail();
         } catch (NullPointerException ex) {}
         try {
             present.ifPresentOrElse(null, () -> {});
             fail();
         } catch (NullPointerException ex) {}
         try {
             empty.ifPresentOrElse(v -> {}, null);
             fail();
         } catch (NullPointerException ex) {}
     }

     @Test(expectedExceptions=NoSuchElementException.class)
     public void testEmptyGet() {
         Optional<Boolean> empty = Optional.empty();

         Boolean got = empty.get();
     }

     @Test(expectedExceptions=NullPointerException.class)
     public void testEmptyOrElseGetNull() {
         Optional<Boolean> empty = Optional.empty();

         Boolean got = empty.orElseGet(null);
     }

     @Test(expectedExceptions=NullPointerException.class)
     public void testEmptyOrElseThrowNull() throws Throwable {
         Optional<Boolean> empty = Optional.empty();

         Boolean got = empty.orElseThrow(null);
     }

     @Test(expectedExceptions=ObscureException.class)
     public void testEmptyOrElseThrow() throws Exception {
         Optional<Boolean> empty = Optional.empty();

         Boolean got = empty.orElseThrow(ObscureException::new);
     }

     @Test(groups = "unit")
     public void testPresent() {
         Optional<Boolean> empty = Optional.empty();
         Optional<String> presentEmptyString = Optional.of("");
         Optional<Boolean> present = Optional.of(Boolean.TRUE);

         // present
         assertTrue(present.equals(present));
         assertTrue(present.equals(Optional.of(Boolean.TRUE)));
         assertTrue(!present.equals(empty));
         assertTrue(Boolean.TRUE.hashCode() == present.hashCode());
         assertTrue(!present.toString().isEmpty());
         assertTrue(!present.toString().equals(presentEmptyString.toString()));
         assertTrue(-1 != present.toString().indexOf(Boolean.TRUE.toString()));
         assertSame(Boolean.TRUE, present.get());

         AtomicBoolean presentCheck = new AtomicBoolean();
         present.ifPresent(v -> presentCheck.set(true));
         assertTrue(presentCheck.get());
         presentCheck.set(false);
         present.ifPresentOrElse(v -> presentCheck.set(true), () -> fail());
         assertTrue(presentCheck.get());

         try {
             present.ifPresent(v -> { throw new ObscureException(); });
             fail();
         } catch (ObscureException expected) {
         } catch (AssertionError e) {
             throw e;
         } catch (Throwable t) {
             fail();
         }
         try {
             present.ifPresentOrElse(v -> { throw new ObscureException(); }, () -> fail());
             fail();
         } catch (ObscureException expected) {
         } catch (AssertionError e) {
             throw e;
         } catch (Throwable t) {
             fail();
         }

         assertSame(Boolean.TRUE, present.orElse(null));
         assertSame(Boolean.TRUE, present.orElse(Boolean.FALSE));
         assertSame(Boolean.TRUE, present.orElseGet(null));
         assertSame(Boolean.TRUE, present.orElseGet(() -> null));
         assertSame(Boolean.TRUE, present.orElseGet(() -> Boolean.FALSE));
         assertSame(Boolean.TRUE, present.<RuntimeException>orElseThrow(null));
         assertSame(Boolean.TRUE, present.<RuntimeException>orElseThrow(ObscureException::new));
     }

     @Test(groups = "unit")
     public void testOfNullable() {
         Optional<String> instance = Optional.ofNullable(null);
         assertFalse(instance.isPresent());

         instance = Optional.ofNullable("Duke");
         assertTrue(instance.isPresent());
         assertEquals(instance.get(), "Duke");
     }

     @Test(groups = "unit")
     public void testFilter() {
         // Null mapper function
         Optional<String> empty = Optional.empty();
         Optional<String> duke = Optional.of("Duke");

         try {
             Optional<String> result = empty.filter(null);
             fail("Should throw NPE on null mapping function");
         } catch (NullPointerException npe) {
             // expected
         }

         Optional<String> result = empty.filter(String::isEmpty);
         assertFalse(result.isPresent());

         result = duke.filter(String::isEmpty);
         assertFalse(result.isPresent());
         result = duke.filter(s -> s.startsWith("D"));
         assertTrue(result.isPresent());
         assertEquals(result.get(), "Duke");

         Optional<String> emptyString = Optional.of("");
         result = emptyString.filter(String::isEmpty);
         assertTrue(result.isPresent());
         assertEquals(result.get(), "");
     }

     @Test(groups = "unit")
     public void testMap() {
         Optional<String> empty = Optional.empty();
         Optional<String> duke = Optional.of("Duke");

         // Null mapper function
         try {
             Optional<Boolean> b = empty.map(null);
             fail("Should throw NPE on null mapping function");
         } catch (NullPointerException npe) {
             // expected
         }

         // Map an empty value
         Optional<Boolean> b = empty.map(String::isEmpty);
         assertFalse(b.isPresent());

         // Map into null
         b = empty.map(n -> null);
         assertFalse(b.isPresent());
         b = duke.map(s -> null);
         assertFalse(b.isPresent());

         // Map to value
         Optional<Integer> l = duke.map(String::length);
         assertEquals(l.get().intValue(), 4);
     }

     @Test(groups = "unit")
     public void testFlatMap() {
         Optional<String> empty = Optional.empty();
         Optional<String> duke = Optional.of("Duke");

         // Null mapper function
         try {
             Optional<Boolean> b = empty.flatMap(null);
             fail("Should throw NPE on null mapping function");
         } catch (NullPointerException npe) {
             // expected
         }

         // Map into null
         try {
             Optional<Boolean> b = duke.flatMap(s -> null);
             fail("Should throw NPE when mapper return null");
         } catch (NullPointerException npe) {
             // expected
         }

         // Empty won't invoke mapper function
         try {
             Optional<Boolean> b = empty.flatMap(s -> null);
             assertFalse(b.isPresent());
         } catch (NullPointerException npe) {
             fail("Mapper function should not be invoked");
         }

         // Map an empty value
         Optional<Integer> l = empty.flatMap(s -> Optional.of(s.length()));
         assertFalse(l.isPresent());

         // Map to value
         Optional<Integer> fixture = Optional.of(Integer.MAX_VALUE);
         l = duke.flatMap(s -> Optional.of(s.length()));
         assertTrue(l.isPresent());
         assertEquals(l.get().intValue(), 4);

         // Verify same instance
         l = duke.flatMap(s -> fixture);
         assertSame(l, fixture);
     }

     @Test(groups = "unit")
     public void testOr() {
         Optional<String> empty = Optional.empty();
         Optional<String> duke = Optional.of("Duke");

         // Null supplier
         try {
             Optional<String> b = empty.or(null);
             fail("Should throw NPE on null supplier");
         } catch (NullPointerException npe) {
             // expected
         }

         // Supply null
         try {
             Optional<String> b = empty.or(() -> null);
             fail("Should throw NPE when supplier returns null");
         } catch (NullPointerException npe) {
             // expected
         }

         // Non-empty won't invoke supplier
         try {
             Optional<String> b = duke.or(() -> null);
             assertTrue(b.isPresent());
         } catch (NullPointerException npe) {
             fail("Supplier should not be invoked");
         }

         // Supply for empty
         Optional<String> suppliedDuke = empty.or(() -> duke);
         assertTrue(suppliedDuke.isPresent());
         assertSame(suppliedDuke, duke);

         // Supply for non-empty
         Optional<String> actualDuke = duke.or(() -> Optional.of("Other Duke"));
         assertTrue(actualDuke.isPresent());
         assertSame(actualDuke, duke);
     }

     @Test(groups = "unit")
     public void testStream() {
         {
             Stream<String> s = Optional.<String>empty().stream();
             assertFalse(s.isParallel());

             Object[] es = s.toArray();
             assertEquals(es.length, 0);
         }

         {
             Stream<String> s = Optional.of("Duke").stream();
             assertFalse(s.isParallel());

             String[] es = s.toArray(String[]::new);
             assertEquals(es.length, 1);
             assertEquals(es[0], "Duke");
         }
     }

     private static class ObscureException extends RuntimeException {

     }
 }
	/*
	* Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	/* @test
	* @summary Basic functional test of Optional
	* @author Mike Duigou
	* @run testng Basic
	*/

	import java.lang.AssertionError;
	import java.lang.NullPointerException;
	import java.lang.Throwable;
	import java.util.NoSuchElementException;
	import java.util.Optional;
	import java.util.concurrent.atomic.AtomicBoolean;
	import java.util.stream.Stream;

	import static org.testng.Assert.*;
	import org.testng.annotations.Test;


	public class Basic {

	@Test(groups = "unit")
	public void testEmpty() {
	Optional<Boolean> empty = Optional.empty();
	Optional<String> presentEmptyString = Optional.of("");
	Optional<Boolean> present = Optional.of(Boolean.TRUE);

	// empty
	assertTrue(empty.equals(empty));
	assertTrue(empty.equals(Optional.empty()));
	assertTrue(!empty.equals(present));
	assertTrue(0 == empty.hashCode());
	assertTrue(!empty.toString().isEmpty());
	assertTrue(!empty.toString().equals(presentEmptyString.toString()));
	assertTrue(!empty.isPresent());

	empty.ifPresent(v -> fail());

	AtomicBoolean emptyCheck = new AtomicBoolean();
	empty.ifPresentOrElse(v -> fail(), () -> emptyCheck.set(true));
	assertTrue(emptyCheck.get());

	try {
	empty.ifPresentOrElse(v -> fail(), () -> { throw new ObscureException(); });
	fail();
	} catch (ObscureException expected) {
	} catch (AssertionError e) {
	throw e;
	} catch (Throwable t) {
	fail();
	}

	assertSame(null, empty.orElse(null));
	RuntimeException orElse = new RuntimeException() { };
	assertSame(Boolean.FALSE, empty.orElse(Boolean.FALSE));
	assertSame(null, empty.orElseGet(() -> null));
	assertSame(Boolean.FALSE, empty.orElseGet(() -> Boolean.FALSE));
	}

	@Test(groups = "unit")
	public void testIfPresentAndOrElseAndNull() {
	Optional<Boolean> empty = Optional.empty();
	Optional<Boolean> present = Optional.of(Boolean.TRUE);

	// No NPE
	present.ifPresentOrElse(v -> {}, null);
	empty.ifPresent(null);
	empty.ifPresentOrElse(null, () -> {});

	// NPE
	try {
	present.ifPresent(null);
	fail();
	} catch (NullPointerException ex) {}
	try {
	present.ifPresentOrElse(null, () -> {});
	fail();
	} catch (NullPointerException ex) {}
	try {
	empty.ifPresentOrElse(v -> {}, null);
	fail();
	} catch (NullPointerException ex) {}
	}

	@Test(expectedExceptions=NoSuchElementException.class)
	public void testEmptyGet() {
	Optional<Boolean> empty = Optional.empty();

	Boolean got = empty.get();
	}

	@Test(expectedExceptions=NullPointerException.class)
	public void testEmptyOrElseGetNull() {
	Optional<Boolean> empty = Optional.empty();

	Boolean got = empty.orElseGet(null);
	}

	@Test(expectedExceptions=NullPointerException.class)
	public void testEmptyOrElseThrowNull() throws Throwable {
	Optional<Boolean> empty = Optional.empty();

	Boolean got = empty.orElseThrow(null);
	}

	@Test(expectedExceptions=ObscureException.class)
	public void testEmptyOrElseThrow() throws Exception {
	Optional<Boolean> empty = Optional.empty();

	Boolean got = empty.orElseThrow(ObscureException::new);
	}

	@Test(groups = "unit")
	public void testPresent() {
	Optional<Boolean> empty = Optional.empty();
	Optional<String> presentEmptyString = Optional.of("");
	Optional<Boolean> present = Optional.of(Boolean.TRUE);

	// present
	assertTrue(present.equals(present));
	assertTrue(present.equals(Optional.of(Boolean.TRUE)));
	assertTrue(!present.equals(empty));
	assertTrue(Boolean.TRUE.hashCode() == present.hashCode());
	assertTrue(!present.toString().isEmpty());
	assertTrue(!present.toString().equals(presentEmptyString.toString()));
	assertTrue(-1 != present.toString().indexOf(Boolean.TRUE.toString()));
	assertSame(Boolean.TRUE, present.get());

	AtomicBoolean presentCheck = new AtomicBoolean();
	present.ifPresent(v -> presentCheck.set(true));
	assertTrue(presentCheck.get());
	presentCheck.set(false);
	present.ifPresentOrElse(v -> presentCheck.set(true), () -> fail());
	assertTrue(presentCheck.get());

	try {
	present.ifPresent(v -> { throw new ObscureException(); });
	fail();
	} catch (ObscureException expected) {
	} catch (AssertionError e) {
	throw e;
	} catch (Throwable t) {
	fail();
	}
	try {
	present.ifPresentOrElse(v -> { throw new ObscureException(); }, () -> fail());
	fail();
	} catch (ObscureException expected) {
	} catch (AssertionError e) {
	throw e;
	} catch (Throwable t) {
	fail();
	}

	assertSame(Boolean.TRUE, present.orElse(null));
	assertSame(Boolean.TRUE, present.orElse(Boolean.FALSE));
	assertSame(Boolean.TRUE, present.orElseGet(null));
	assertSame(Boolean.TRUE, present.orElseGet(() -> null));
	assertSame(Boolean.TRUE, present.orElseGet(() -> Boolean.FALSE));
	assertSame(Boolean.TRUE, present.<RuntimeException>orElseThrow(null));
	assertSame(Boolean.TRUE, present.<RuntimeException>orElseThrow(ObscureException::new));
	}

	@Test(groups = "unit")
	public void testOfNullable() {
	Optional<String> instance = Optional.ofNullable(null);
	assertFalse(instance.isPresent());

	instance = Optional.ofNullable("Duke");
	assertTrue(instance.isPresent());
	assertEquals(instance.get(), "Duke");
	}

	@Test(groups = "unit")
	public void testFilter() {
	// Null mapper function
	Optional<String> empty = Optional.empty();
	Optional<String> duke = Optional.of("Duke");

	try {
	Optional<String> result = empty.filter(null);
	fail("Should throw NPE on null mapping function");
	} catch (NullPointerException npe) {
	// expected
	}

	Optional<String> result = empty.filter(String::isEmpty);
	assertFalse(result.isPresent());

	result = duke.filter(String::isEmpty);
	assertFalse(result.isPresent());
	result = duke.filter(s -> s.startsWith("D"));
	assertTrue(result.isPresent());
	assertEquals(result.get(), "Duke");

	Optional<String> emptyString = Optional.of("");
	result = emptyString.filter(String::isEmpty);
	assertTrue(result.isPresent());
	assertEquals(result.get(), "");
	}

	@Test(groups = "unit")
	public void testMap() {
	Optional<String> empty = Optional.empty();
	Optional<String> duke = Optional.of("Duke");

	// Null mapper function
	try {
	Optional<Boolean> b = empty.map(null);
	fail("Should throw NPE on null mapping function");
	} catch (NullPointerException npe) {
	// expected
	}

	// Map an empty value
	Optional<Boolean> b = empty.map(String::isEmpty);
	assertFalse(b.isPresent());

	// Map into null
	b = empty.map(n -> null);
	assertFalse(b.isPresent());
	b = duke.map(s -> null);
	assertFalse(b.isPresent());

	// Map to value
	Optional<Integer> l = duke.map(String::length);
	assertEquals(l.get().intValue(), 4);
	}

	@Test(groups = "unit")
	public void testFlatMap() {
	Optional<String> empty = Optional.empty();
	Optional<String> duke = Optional.of("Duke");

	// Null mapper function
	try {
	Optional<Boolean> b = empty.flatMap(null);
	fail("Should throw NPE on null mapping function");
	} catch (NullPointerException npe) {
	// expected
	}

	// Map into null
	try {
	Optional<Boolean> b = duke.flatMap(s -> null);
	fail("Should throw NPE when mapper return null");
	} catch (NullPointerException npe) {
	// expected
	}

	// Empty won't invoke mapper function
	try {
	Optional<Boolean> b = empty.flatMap(s -> null);
	assertFalse(b.isPresent());
	} catch (NullPointerException npe) {
	fail("Mapper function should not be invoked");
	}

	// Map an empty value
	Optional<Integer> l = empty.flatMap(s -> Optional.of(s.length()));
	assertFalse(l.isPresent());

	// Map to value
	Optional<Integer> fixture = Optional.of(Integer.MAX_VALUE);
	l = duke.flatMap(s -> Optional.of(s.length()));
	assertTrue(l.isPresent());
	assertEquals(l.get().intValue(), 4);

	// Verify same instance
	l = duke.flatMap(s -> fixture);
	assertSame(l, fixture);
	}

	@Test(groups = "unit")
	public void testOr() {
	Optional<String> empty = Optional.empty();
	Optional<String> duke = Optional.of("Duke");

	// Null supplier
	try {
	Optional<String> b = empty.or(null);
	fail("Should throw NPE on null supplier");
	} catch (NullPointerException npe) {
	// expected
	}

	// Supply null
	try {
	Optional<String> b = empty.or(() -> null);
	fail("Should throw NPE when supplier returns null");
	} catch (NullPointerException npe) {
	// expected
	}

	// Non-empty won't invoke supplier
	try {
	Optional<String> b = duke.or(() -> null);
	assertTrue(b.isPresent());
	} catch (NullPointerException npe) {
	fail("Supplier should not be invoked");
	}

	// Supply for empty
	Optional<String> suppliedDuke = empty.or(() -> duke);
	assertTrue(suppliedDuke.isPresent());
	assertSame(suppliedDuke, duke);

	// Supply for non-empty
	Optional<String> actualDuke = duke.or(() -> Optional.of("Other Duke"));
	assertTrue(actualDuke.isPresent());
	assertSame(actualDuke, duke);
	}

	@Test(groups = "unit")
	public void testStream() {
	{
	Stream<String> s = Optional.<String>empty().stream();
	assertFalse(s.isParallel());

	Object[] es = s.toArray();
	assertEquals(es.length, 0);
	}

	{
	Stream<String> s = Optional.of("Duke").stream();
	assertFalse(s.isParallel());

	String[] es = s.toArray(String[]::new);
	assertEquals(es.length, 1);
	assertEquals(es[0], "Duke");
	}
	}

	private static class ObscureException extends RuntimeException {

	}
	}