1 files changed, 25 insertions, 0 deletions
diff --git a/core-database/src/main/scala/xyz/driver/core/database/Converters.scala b/core-database/src/main/scala/xyz/driver/core/database/Converters.scala
new file mode 100644
index 0000000..b0054ad
--- /dev/null
+++ b/core-database/src/main/scala/xyz/driver/core/database/Converters.scala
@@ -0,0 +1,25 @@
+package xyz.driver.core.database
+
+import scala.reflect.ClassTag
+
+/**
+  * Helper methods for converting between table rows and Scala objects
+  */
+trait Converters {
+  def fromStringOrThrow[ADT](entityStr: String, mapper: (String => Option[ADT]), entityName: String): ADT =
+    mapper(entityStr).getOrElse(throw DatabaseException(s"Invalid $entityName in database: $entityStr"))
+
+  def expectValid[ADT](mapper: String => Option[ADT], query: String)(implicit ct: ClassTag[ADT]): ADT =
+    fromStringOrThrow[ADT](query, mapper, ct.toString())
+
+  def expectExistsAndValid[ADT](mapper: String => Option[ADT], query: Option[String], contextMsg: String = "")(
+      implicit ct: ClassTag[ADT]): ADT = {
+    expectValid[ADT](mapper, query.getOrElse(throw DatabaseException(contextMsg)))
+  }
+
+  def expectValidOrEmpty[ADT](mapper: String => Option[ADT], query: Option[String], contextMsg: String = "")(
+      implicit ct: ClassTag[ADT]): Option[ADT] = {
+    query.map(expectValid[ADT](mapper, _))
+  }
+}
+final case class DatabaseException(message: String = "Database access error") extends RuntimeException(message)