Add test for SimplePartitioner

Author: fmbenhassine

spring-batch-core/src/test/java/org/springframework/batch/core/partition/support/SimplePartitionerTests.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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 org.springframework.batch.core.partition.support;
+
+import java.util.Map;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import org.springframework.batch.item.ExecutionContext;
+
+/**
+ * @author Mahmoud Ben Hassine
+ */
+public class SimplePartitionerTests {
+
+    @Test
+    public void testPartition() {
+        // given
+        SimplePartitioner partitioner = new SimplePartitioner();
+
+        // when
+        Map<String, ExecutionContext> partitions = partitioner.partition(3);
+
+        // then
+        Assert.assertNotNull(partitions);
+        Assert.assertEquals(3, partitions.size());
+        Assert.assertNotNull(partitions.get("partition0"));
+        Assert.assertNotNull(partitions.get("partition1"));
+        Assert.assertNotNull(partitions.get("partition2"));
+    }
+}