From: David ‘Bombe’ Roden <bombe@pterodactylus.net>
Date: Mon, 24 Nov 2014 06:19:02 +0000 (+0100)
Subject: Add helper methods for Optionals.
X-Git-Tag: 0.9-rc1^2~3^2~16
X-Git-Url: https://git.pterodactylus.net/?a=commitdiff_plain;h=d925df7b6a110eeec00284958903800f60631974;p=Sone.git

Add helper methods for Optionals.
---

diff --git a/src/main/java/net/pterodactylus/sone/utils/Optionals.java b/src/main/java/net/pterodactylus/sone/utils/Optionals.java
new file mode 100644
index 0000000..67132aa
--- /dev/null
+++ b/src/main/java/net/pterodactylus/sone/utils/Optionals.java
@@ -0,0 +1,32 @@
+package net.pterodactylus.sone.utils;
+
+import com.google.common.base.Function;
+import com.google.common.base.Optional;
+import com.google.common.base.Predicate;
+
+/**
+ * Helper methods for dealing with {@link Optional}s.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class Optionals {
+
+	public static Predicate<Optional<?>> isPresent() {
+		return new Predicate<Optional<?>>() {
+			@Override
+			public boolean apply(Optional<?> input) {
+				return input.isPresent();
+			}
+		};
+	}
+
+	public static <T> Function<Optional<T>, T> get() {
+		return new Function<Optional<T>, T>() {
+			@Override
+			public T apply(Optional<T> input) {
+				return input.get();
+			}
+		};
+	}
+
+}
diff --git a/src/test/java/net/pterodactylus/sone/utils/OptionalsTest.java b/src/test/java/net/pterodactylus/sone/utils/OptionalsTest.java
new file mode 100644
index 0000000..0f7dee3
--- /dev/null
+++ b/src/test/java/net/pterodactylus/sone/utils/OptionalsTest.java
@@ -0,0 +1,52 @@
+package net.pterodactylus.sone.utils;
+
+import java.util.Arrays;
+import java.util.List;
+
+import com.google.common.base.Optional;
+import com.google.common.collect.FluentIterable;
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.Matchers;
+import org.junit.Test;
+
+/**
+ * Unit test for {@link Optionals}.
+ *
+ * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+ */
+public class OptionalsTest {
+
+	private final Object object1 = new Object();
+	private final Object object2 = new Object();
+	private final Object object3 = new Object();
+
+	@Test
+	public void canCreateOptionals() {
+		new Optionals();
+	}
+
+	@Test
+	public void isPresentFiltersCorrectOptionals() {
+		List<Optional<Object>> optionals = Arrays.asList(
+				Optional.of(object1), Optional.absent(),
+				Optional.of(object2), Optional.absent(),
+				Optional.of(object3), Optional.absent()
+		);
+		List<Optional<Object>> filteredOptionals =
+				FluentIterable.from(optionals).filter(Optionals.isPresent()).toList();
+		MatcherAssert.assertThat(filteredOptionals, Matchers.contains(
+				Optional.of(object1), Optional.of(object2), Optional.of(object3)));
+	}
+
+	@Test
+	public void getReturnsCorrectValues() {
+		List<Optional<Object>> optionals = Arrays.asList(
+				Optional.of(object1),
+				Optional.of(object2),
+				Optional.of(object3)
+		);
+		List<Object> objects = FluentIterable.from(optionals).transform(Optionals.get()).toList();
+		MatcherAssert.assertThat(objects, Matchers.contains(object1, object2, object3));
+	}
+
+}