Add unit tests for list extension

dpadrecyclerview/src/test/java/com/rubensousa/dpadrecyclerview/layoutmanager/ListExtensionTest.kt

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2024 Rúben Sousa
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rubensousa.dpadrecyclerview.layoutmanager
+
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+
+class ListExtensionTest {
+
+    @Test
+    fun `empty list does nothing`() {
+        // given
+        val list = emptyList<Int>()
+        var invoked = false
+
+        // when
+        list.forEachReversed {
+            invoked = true
+        }
+
+        // then
+        assertThat(invoked).isFalse()
+    }
+
+    @Test
+    fun `removing list within itself works`() {
+        // given
+        val list = mutableListOf("value1", "value2", "value3")
+
+        // when
+        list.forEachReversed { value ->
+            list.remove(value)
+        }
+
+        // then
+        assertThat(list).isEmpty()
+    }
+
+    @Test
+    fun `values are iterated in reverse order`() {
+        // given
+        val list = mutableListOf("value1", "value2", "value3")
+        val iterated = mutableListOf<String>()
+
+        // when
+        list.forEachReversed { value ->
+            iterated.add(value)
+        }
+
+        // then
+        assertThat(iterated).isEqualTo(list.reversed())
+    }
+
+}