1 files changed, 78 insertions, 0 deletions

diff --git a/store/src/test/java/tools/refinery/data/util/CollectionsUtilTests.java b/store/src/test/java/tools/refinery/data/util/CollectionsUtilTests.java
new file mode 100644
index 00000000..39ff4aca
--- /dev/null
+++ b/store/src/test/java/tools/refinery/data/util/CollectionsUtilTests.java
@@ -0,0 +1,78 @@
+package tools.refinery.data.util;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static tools.refinery.data.util.CollectionsUtil.filter;
+import static tools.refinery.data.util.CollectionsUtil.map;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.NoSuchElementException;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+class CollectionsUtilTests {
+        List<Integer> list10 = List.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
+        List<String> listTen = List.of("1", "2", "3", "4", "5", "6", "7", "8", "9", "10");
+
+        private static <T> void compare(Iterable<T> a, Iterable<T> b) {
+                List<T> listA = toList(a);
+                List<T> listB = toList(b);
+                assertEquals(listA, listB);
+        }
+
+        private static <T> List<T> toList(Iterable<T> a) {
+                List<T> result = new ArrayList<T>();
+                Iterator<T> iterator = a.iterator();
+                while (iterator.hasNext()) {
+                        result.add(iterator.next());
+                }
+                return result;
+        }
+
+        @Test
+        void testFilterEven() {
+                compare(List.of(2, 4, 6, 8, 10), filter(list10, (x -> x % 2 == 0)));
+        }
+
+        @Test
+        void testFilterOdd() {
+                compare(List.of(1, 3, 5, 7, 9), filter(list10, (x -> x % 2 == 1)));
+        }
+
+        @Test
+        void testFilterFalse() {
+                compare(List.of(), filter(list10, (x -> false)));
+        }
+
+        @Test
+        void testFilterTrue() {
+                compare(list10, filter(list10, (x -> true)));
+        }
+
+        @Test
+        void testFilterEmpty() {
+                compare(List.of(), filter(List.of(), (x -> true)));
+        }
+
+        @Test()
+        void testNoSuchElement() {
+                Iterable<Integer> iterable = filter(list10, (x -> x % 2 == 0));
+                Iterator<Integer> iterator = iterable.iterator();
+                while (iterator.hasNext()) {
+                        iterator.next();
+                }
+                Assertions.assertThrows(NoSuchElementException.class, () -> iterator.next());
+        }
+
+        @Test()
+        void mapTest() {
+                compare(listTen, map(list10, x -> x.toString()));
+        }
+
+        @Test()
+        void mapEmtyTest() {
+                compare(List.of(), map(List.of(), x -> x.toString()));
+        }
+}