Fix #293 regression. isGreaterThan(A)/isLesserThan(A) were not using strict inequality

jbgi · web-flow · commit 49c6f8d6fd51 · 2016-07-22T14:32:05.000+02:00
diff --git a/core/src/main/java/fj/Ord.java b/core/src/main/java/fj/Ord.java
@@ -129,7 +129,7 @@ public boolean isGreaterThan(final A a1, final A a2) {
    * @return A function that returns true if its argument is less than the argument to this method.
    */
   public F<A, Boolean> isLessThan(final A a) {
-    return compose(o -> o != Ordering.LT, f.f(a));
+    return compose(o -> o == Ordering.GT, f.f(a));
   }
 
   /**
@@ -139,7 +139,7 @@ public F<A, Boolean> isLessThan(final A a) {
    * @return A function that returns true if its argument is greater than the argument to this method.
    */
   public F<A, Boolean> isGreaterThan(final A a) {
-    return compose(o -> o != Ordering.GT, f.f(a));
+    return compose(o -> o == Ordering.LT, f.f(a));
   }
 
   /**
diff --git a/core/src/test/java/fj/OrdTest.java b/core/src/test/java/fj/OrdTest.java
@@ -0,0 +1,27 @@
+package fj;
+
+import org.junit.Test;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+public class OrdTest {
+
+  @Test
+  public void isGreaterThan() {
+    F<Long, Boolean> pred = Ord.longOrd.isGreaterThan(1L);
+
+    assertThat(pred.f(0L), is(false));
+    assertThat(pred.f(1L), is(false));
+    assertThat(pred.f(2L), is(true));
+  }
+
+  @Test
+  public void isLessThan() {
+    F<Long, Boolean> pred = Ord.longOrd.isLessThan(1L);
+
+    assertThat(pred.f(0L), is(true));
+    assertThat(pred.f(1L), is(false));
+    assertThat(pred.f(2L), is(false));
+  }
+}
