Move hasFeature to ExtraMatchers

1 files changed, 15 insertions, 0 deletions

diff --git a/src/test/java/org/zwobble/couscous/tests/util/ExtraMatchers.java b/src/test/java/org/zwobble/couscous/tests/util/ExtraMatchers.java
index 3107d53..d79cb05 100644
--- a/src/test/java/org/zwobble/couscous/tests/util/ExtraMatchers.java
+++ b/src/test/java/org/zwobble/couscous/tests/util/ExtraMatchers.java
@@ -2,8 +2,11 @@ package org.zwobble.couscous.tests.util;
 
 import org.hamcrest.Description;
 import org.hamcrest.DiagnosingMatcher;
+import org.hamcrest.FeatureMatcher;
 import org.hamcrest.Matcher;
 
+import java.util.function.Function;
+
 public class ExtraMatchers {
     public static <T, U> Matcher<T> isInstance(Class<U> type, Matcher<? super U> downcastMatcher) {
         return new DiagnosingMatcher<T>() {
@@ -36,4 +39,16 @@ public class ExtraMatchers {
             }
         };
     }
+
+    public static <T, U> Matcher<T> hasFeature(
+        String name,
+        Function<? super T, U> extract,
+        Matcher<? super U> subMatcher) {
+        return new FeatureMatcher<T, U>(subMatcher, name, name) {
+            @Override
+            protected U featureValueOf(T actual) {
+                return extract.apply(actual);
+            }
+        };
+    }
 }