Add Reader/Writer tests

gliptak · gliptak · commit c2392a12e6e4 · 2018-08-13T16:40:27.000-04:00
Signed-off-by: Gábor Lipták &lt;gliptak@gmail.com&gt;
diff --git a/props-core/src/test/java/fj/data/ReaderTest.java b/props-core/src/test/java/fj/data/ReaderTest.java
@@ -11,6 +11,8 @@
 import static fj.test.Cogen.cogenInteger;
 import static fj.test.Property.prop;
 import static fj.test.Property.property;
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 
 /**
@@ -24,7 +26,6 @@ public void testMap() {
         // example taken from http://learnyouahaskell.com/for-a-few-monads-more
         int x = Reader.unit((Integer i) -> i + 3).map(i -> i * 5).f(8);
         assertTrue(x == 55);
-//        System.out.println(x); // 55
     }
 
     @Test
@@ -108,6 +109,19 @@ public void testAssociativity() {
         PropertyAssert.assertResult(p);
     }
 
+    @Test
+    public void testAndThen() {
+        final int y = Reader.unit((Integer i) -> i * 2).andThen(i -> i + 10).f(10);
+        assertThat(y, is(30));
+    }
+
+    @Test
+    public void testBind() {
+        final int y = Reader.unit((Integer i) -> i * 2)
+                .bind(a -> Reader.unit(i -> a + i + 11)).f(10);
+        assertThat(y, is(41));
+    }
+
     public Gen<Reader<Integer, Integer>> arbReader() {
         return Arbitrary.arbReader(cogenInteger, arbInteger);
     }
diff --git a/props-core/src/test/java/fj/data/WriterTest.java b/props-core/src/test/java/fj/data/WriterTest.java
@@ -2,8 +2,7 @@
 
 import fj.Equal;
 import fj.F;
-import fj.data.test.PropertyAssert;
-import fj.test.Arbitrary;
+import fj.P;
 import fj.test.Gen;
 import fj.test.Property;
 import org.junit.Assert;
@@ -14,7 +13,8 @@
 import static fj.test.Cogen.cogenInteger;
 import static fj.test.Property.prop;
 import static fj.test.Property.property;
-import static org.junit.Assert.assertTrue;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
 
 /**
  * Created by MarkPerry on 17/12/2014.
@@ -107,7 +107,13 @@ public void testAssociativity() {
         assertResult(p);
     }
 
-
+    @Test
+    public void testUnit() {
+        Writer<String, String> w = Writer.unit("+").tell("foo").tell("bar");
+        assertThat(w.run(), is(P.p("foobar", "+")));
+        assertThat(w.log(), is("foobar"));
+        assertThat(w.value(), is("+"));
+    }
 
 
 }
