#35: Simplify working with the query results in the DB tests (#37)

* method `@=` for Option types as a synonym for `contains`
* method 'noMore` as an alias for `hasMore` in `QueryResult` class
* enhanced tests for `QueryResultRowIntegration`
* changed the return type of `QueryResultRow.apply` from `Option[Object]` to `Option[Any]`

balta/src/main/scala/za/co/absa/db/balta/classes/QueryResult.scala

@@ -56,4 +56,9 @@ class QueryResult(resultSet: ResultSet) extends Iterator[QueryResultRow] {
       throw new NoSuchElementException("No more rows in the result set")
     }
   }
+
+  /**
+   * A naturally easily understandable opposite of `hasNext`
+   */
+  def noMore: Boolean = !hasNext
 }

balta/src/main/scala/za/co/absa/db/balta/classes/QueryResultRow.scala

@@ -37,14 +37,27 @@ class QueryResultRow private[classes](val rowNumber: Int,
   def columnCount: Int = fields.length
   def columnNumber(columnLabel: String): Int = columnNames(columnLabel.toLowerCase)
 
-  def apply(column: Int): Option[Object] = fields(column - 1)
-  def apply(columnLabel: String): Option[Object] = apply(columnNumber(columnLabel))
-
-  def getAs[T](column: Int, transformer: TransformerFnc[T]): Option[T] = apply(column).map(transformer)
-  def getAs[T](column: Int): Option[T] = apply(column)map(_.asInstanceOf[T])
+  /**
+   * Extracts a value from the row by column number.
+   * @param column  - the number of the column, 1 based
+   * @return        - the value stored in the column, type `Any` is for warningless comparison with any type
+   */
+  def apply(column: Int): Option[Any] = getObject(column - 1)
+  /**
+   * Extracts a value from the row by column name.
+   * @param columnLabel - the name of the column
+   * @return            - the value stored in the column, type `Any` is for warningless comparison with any type
+   */
+  def apply(columnLabel: String): Option[Any] = getObject(columnNumber(columnLabel))
+
+  def getAs[T](column: Int, transformer: TransformerFnc[T]): Option[T] = getObject(column).map(transformer)
+  def getAs[T](column: Int): Option[T] = getObject(column)map(_.asInstanceOf[T])
 
   def getAs[T](columnLabel: String, transformer: TransformerFnc[T]): Option[T] = getAs(columnNumber(columnLabel), transformer)
-  def getAs[T](columnLabel: String): Option[T] = apply(columnNumber(columnLabel)).map(_.asInstanceOf[T])
+  def getAs[T](columnLabel: String): Option[T] = getObject(columnNumber(columnLabel)).map(_.asInstanceOf[T])
+
+  def getObject(column: Int): Option[Object] = fields(column - 1)
+  def getObject(columnLabel: String): Option[Object] = getObject(columnNumber(columnLabel))
 
   def getBoolean(column: Int): Option[Boolean] = getAs(column: Int, {item: Object => item.asInstanceOf[Boolean]})
   def getBoolean(columnLabel: String): Option[Boolean] = getBoolean(columnNumber(columnLabel))
@@ -59,7 +72,6 @@ class QueryResultRow private[classes](val rowNumber: Int,
   }
   def getChar(columnLabel: String): Option[Char] = getChar(columnNumber(columnLabel))
 
-
   def getString(column: Int): Option[String] = getAs(column: Int, {item: Object => item.asInstanceOf[String]})
   def getString(columnLabel: String): Option[String] = getString(columnNumber(columnLabel))
 

balta/src/main/scala/za/co/absa/db/balta/classes/setter/SetterFnc.scala

@@ -16,12 +16,12 @@
 
 package za.co.absa.db.balta.classes.setter
 
-import java.sql.{Date, PreparedStatement, Time, Timestamp, Types => SqlTypes}
+import java.sql.{Date, PreparedStatement, Time, Types => SqlTypes}
 import java.util.UUID
 import org.postgresql.util.PGobject
 import za.co.absa.db.balta.classes.simple.JsonBString
 
-import java.time.{Instant, LocalDate, LocalTime, OffsetDateTime, ZoneId, ZoneOffset}
+import java.time.{Instant, LocalDate, LocalTime, OffsetDateTime, ZoneOffset}
 
 /**
  * This is a trait representing a function that sets a value in a prepared statement.

balta/src/main/scala/za/co/absa/db/balta/implicits/OptionImplicits.scala

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2023 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.db.balta.implicits
+
+object OptionImplicits {
+  implicit class OptionEnhancements[T](val option: Option[T]) extends AnyVal {
+    /**
+     * Gets the `option` value or throws the provided exception
+     *
+     * @param exception the exception to throw in case the `option` is None
+     * @return
+     */
+    def getOrThrow(exception: => Throwable): T = {
+      option.getOrElse(throw exception)
+    }
+
+    /**
+     * The function is an alias for `contains` method, but shorter and suitable for inflix usage
+     *
+     * @param value the value to check if present in the `option`
+     * @return      true if the `option` is defined and contains the provided value, false otherwise
+     */
+    def @=(value: T): Boolean = option.contains(value)
+  }
+
+}

balta/src/test/scala/za/co/absa/db/balta/classes/QueryResultRowIntegrationTests.scala

@@ -54,6 +54,15 @@ class QueryResultRowIntegrationTests extends AnyFunSuiteLike with DBTestingConne
     assert(result == expecedResult)
   }
 
+  test("columnCount") {
+    assert(tableRows.head.columnCount == 14)
+  }
+
+  test("rowNumber") {
+    assert(tableRows.head.rowNumber == 1)
+    assert(tableRows.tail.head.rowNumber == 2)
+  }
+
   test("getLong") {
     //first row
     assert(tableRows.head.getLong(1).contains(1))

balta/src/test/scala/za/co/absa/db/balta/implicits/OptionImplicitsUnitTests.scala

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2023 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.db.balta.implicits
+
+import org.scalatest.funsuite.AnyFunSuiteLike
+import za.co.absa.db.balta.implicits.OptionImplicits.OptionEnhancements
+
+
+class OptionImplicitsUnitTests extends AnyFunSuiteLike {
+  test("getOrThrow returns the value if it is defined") {
+    val opt = Some(true)
+    assert(opt.getOrThrow(new Exception("Foo")))
+  }
+
+  test("getOrThrow throws an exception if the value is not defined") {
+    val opt = None
+    assertThrows[Exception](opt.getOrThrow(new Exception("Foo")))
+  }
+
+  test("@= returns true if the value is defined and equals the provided value") {
+    val opt = Some(42)
+    assert(opt @= 42)
+  }
+
+  test("@= returns false if the value is defined but does not equal the provided value") {
+    val opt = Some(42)
+    assert(!(opt @= 43))
+  }
+
+  test("@= returns false if the value is not defined") {
+    val opt = None
+    assert(!(opt @= 42))
+  }
+
+}