More work on IOMatcher

jnape · jnape · commit f0bfb0492cbe · 2019-08-15T17:17:49.000-05:00
diff --git a/src/test/java/testsupport/matchers/IOMatcher.java b/src/test/java/testsupport/matchers/IOMatcher.java
@@ -10,6 +10,7 @@
 
 import static com.jnape.palatable.lambda.adt.Either.left;
 import static com.jnape.palatable.lambda.adt.Either.right;
+import static com.jnape.palatable.lambda.io.IO.io;
 import static org.hamcrest.Matchers.anything;
 
 public final class IOMatcher<A> extends TypeSafeMatcher<IO<A>> {
@@ -26,24 +27,35 @@ private IOMatcher(Either<Matcher<? super Throwable>, Matcher<? super A>> matcher
     protected boolean matchesSafely(IO<A> io) {
         Either<Throwable, A> res = io.safe().unsafePerformIO();
         resultRef.set(res);
-        return res.match(t -> matcher.match(tMatcher -> tMatcher.matches(t), aMatcher -> false),
-                         a -> matcher.match(tMatcher -> false, aMatcher -> aMatcher.matches(a)));
+        return res.match(t -> matcher.match(tMatcher -> tMatcher.matches(t),
+                                            aMatcher -> false),
+                         a -> matcher.match(tMatcher -> false,
+                                            aMatcher -> aMatcher.matches(a)));
     }
 
     @Override
     public void describeTo(Description description) {
-        throw new UnsupportedOperationException();
+        matcher.match(m -> io(() -> m.describeTo(description.appendText("IO throwing exception matching "))),
+                      m -> io(() -> m.describeTo(description.appendText("IO yielding value matching "))))
+                .unsafePerformIO();
     }
 
-    public static <A> IOMatcher<A> isIOThat(Matcher<? super A> matcher) {
+    @Override
+    protected void describeMismatchSafely(IO<A> item, Description mismatchDescription) {
+        resultRef.get().match(t -> io(() -> mismatchDescription.appendText("IO threw " + t)),
+                              a -> io(() -> mismatchDescription.appendText("IO yielded value " + a)))
+                .unsafePerformIO();
+    }
+
+    public static <A> IOMatcher<A> yieldsValue(Matcher<? super A> matcher) {
         return new IOMatcher<>(right(matcher));
     }
 
-    public static <A> IOMatcher<A> isIOThatCompletesNormally() {
-        return isIOThat(anything());
+    public static <A> IOMatcher<A> completesNormally() {
+        return yieldsValue(anything());
     }
 
-    public static <A> IOMatcher<A> isIOThatThrows(Matcher<? super Throwable> throwableMatcher) {
+    public static <A> IOMatcher<A> throwsException(Matcher<? super Throwable> throwableMatcher) {
         return new IOMatcher<>(left(throwableMatcher));
     }
 }
