Merge pull request #41 from alexengrig/fix/34

Fixes #34

Author: alexengrig

src/test/java/io/github/alexengrig/lambdax/collection/QueueXTest.java

@@ -16,9 +16,11 @@
 
 package io.github.alexengrig.lambdax.collection;
 
+import io.github.alexengrig.lambdax.OptionalX;
 import org.junit.Test;
 
 import java.util.ArrayDeque;
+import java.util.Optional;
 import java.util.Queue;
 import java.util.function.Consumer;
 import java.util.function.Predicate;
@@ -34,6 +36,16 @@ public void checkAdd() {
         assertTrue(addValue.test(numbers));
     }
 
+    @Test
+    public void checkAddOptional() {
+        double value = 1.1;
+        Queue<Number> numbers = new ArrayDeque<>();
+        Queue<Number> actual = Optional.of(numbers)
+                .filter(QueueX.add(value))
+                .orElseThrow(IllegalStateException::new);
+        assertTrue(actual.contains(value));
+    }
+
     @Test
     public void checkOnlyAdd() {
         int value = 2;
@@ -43,6 +55,16 @@ public void checkOnlyAdd() {
         assertTrue(numbers.contains(value));
     }
 
+    @Test
+    public void checkOnlyAddOptional() {
+        double value = 2.1;
+        Queue<Number> numbers = new ArrayDeque<>();
+        Queue<Number> actual = Optional.of(numbers)
+                .map(OptionalX.peek(QueueX.onlyAdd(value)))
+                .orElseThrow(IllegalStateException::new);
+        assertTrue(actual.contains(value));
+    }
+
     @Test
     public void checkOffer() {
         int value = 3;
@@ -51,6 +73,16 @@ public void checkOffer() {
         assertTrue(offerValue.test(numbers));
     }
 
+    @Test
+    public void checkOfferOptional() {
+        double value = 3.1;
+        Queue<Number> numbers = new ArrayDeque<>();
+        Queue<Number> actual = Optional.of(numbers)
+                .filter(QueueX.offer(value))
+                .orElseThrow(IllegalStateException::new);
+        assertTrue(actual.contains(value));
+    }
+
     @Test
     public void checkOnlyOffer() {
         int value = 4;
@@ -59,4 +91,14 @@ public void checkOnlyOffer() {
         onlyOfferValue.accept(numbers);
         assertTrue(numbers.contains(value));
     }
+
+    @Test
+    public void checkOnlyOfferOptional() {
+        double value = 4.1;
+        Queue<Number> numbers = new ArrayDeque<>();
+        Queue<Number> actual = Optional.of(numbers)
+                .map(OptionalX.peek(QueueX.onlyOffer(value)))
+                .orElseThrow(IllegalStateException::new);
+        assertTrue(actual.contains(value));
+    }
 }