1 files changed, 46 insertions, 0 deletions
diff --git a/src/test/java/org/zwobble/mammoth/tests/Arguments.java b/src/test/java/org/zwobble/mammoth/tests/Arguments.java
new file mode 100644
index 0000000..afb20bb
--- /dev/null
+++ b/src/test/java/org/zwobble/mammoth/tests/Arguments.java
@@ -0,0 +1,46 @@
+package org.zwobble.mammoth.tests;
+
+import org.zwobble.mammoth.internal.util.Iterables;
+
+import java.util.Iterator;
+
+import static java.util.Arrays.asList;
+
+public class Arguments {
+    private final Object[] arguments;
+
+    public Arguments(Object[] arguments) {
+        this.arguments = arguments;
+    }
+
+    public <T> T get(Class<T> clazz) {
+        return only(getAll(clazz));
+    }
+
+    public <T> T get(Class<T> clazz, T defaultValue) {
+        Iterator<T> arguments = getAll(clazz).iterator();
+        if (!arguments.hasNext()) {
+            return defaultValue;
+        } else {
+            return only(arguments);
+        }
+    }
+
+    private <T> Iterable<T> getAll(Class<T> clazz) {
+        return Iterables.lazyFilter(asList(arguments), clazz);
+    }
+
+
+    private <T> T only(Iterable<T> iterable) {
+        return only(iterable.iterator());
+    }
+
+    private <T> T only(Iterator<T> iterator) {
+        T value = iterator.next();
+        if (iterator.hasNext()) {
+            throw new RuntimeException("Expected exactly one element, but had multiple elements");
+        } else {
+            return value;
+        }
+    }
+}