#520 Add unit test suite for the offset manager utils.

pramen/core/src/test/scala/za/co/absa/pramen/core/tests/bookkeeper/OffsetManagerUtilsSuite.scala

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2022 ABSA Group Limited
+ *
+ * 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 za.co.absa.pramen.core.tests.bookkeeper
+
+import org.apache.spark.sql.functions.col
+import org.apache.spark.sql.types.TimestampType
+import org.scalatest.wordspec.AnyWordSpec
+import za.co.absa.pramen.api.offset.{OffsetType, OffsetValue}
+import za.co.absa.pramen.core.base.SparkTestBase
+import za.co.absa.pramen.core.bookkeeper.OffsetManagerUtils
+
+import java.time.Instant
+
+class OffsetManagerUtilsSuite extends AnyWordSpec with SparkTestBase {
+
+  import spark.implicits._
+
+  "getMinMaxValueFromData" should {
+    "work for an integral data type" in {
+      val df = List(("A", 1), ("B", 2), ("C", 3)).toDF("a", "offset")
+
+      val (minValue, maxValue) = OffsetManagerUtils.getMinMaxValueFromData(df, "offset", OffsetType.IntegralType).get
+
+      assert(minValue == OffsetValue.IntegralValue(1))
+      assert(maxValue == OffsetValue.IntegralValue(3))
+    }
+
+    "work for an string data type" in {
+      val df = List(("A", 1), ("B", 2), ("C", 3)).toDF("offset", "b")
+
+      val (minValue, maxValue) = OffsetManagerUtils.getMinMaxValueFromData(df, "offset", OffsetType.StringType).get
+
+      assert(minValue == OffsetValue.StringValue("A"))
+      assert(maxValue == OffsetValue.StringValue("C"))
+    }
+
+    "work for an datetime data type" in {
+      val baseTime = 1733989092000L
+      val df = List(("A", baseTime), ("B", baseTime + 1000), ("C", baseTime + 1500)).toDF("a", "offset")
+        .withColumn("offset", (col("offset") / 1000).cast(TimestampType))
+
+      val (minValue, maxValue) = OffsetManagerUtils.getMinMaxValueFromData(df, "offset", OffsetType.DateTimeType).get
+
+      assert(minValue == OffsetValue.DateTimeValue(Instant.ofEpochMilli(baseTime)))
+      assert(maxValue == OffsetValue.DateTimeValue(Instant.ofEpochMilli(baseTime + 1500)))
+    }
+  }
+}