Merge pull request #109 from drivergroup/api-1252-generalize-db-errors

[API-1252] Add general method for checking for database errors

2 files changed, 30 insertions, 2 deletions

diff --git a/src/main/scala/xyz/driver/core/database/Converters.scala b/src/main/scala/xyz/driver/core/database/Converters.scala
new file mode 100644
index 0000000..cfc5afd
--- /dev/null
+++ b/src/main/scala/xyz/driver/core/database/Converters.scala
@@ -0,0 +1,14 @@
+package xyz.driver.core.database
+
+import xyz.driver.core.rest.errors.DatabaseException
+
+import scala.reflect.ClassTag
+
+trait Converters {
+  def fromStringOrThrow[T](entityStr: String, mapper: (String => Option[T]), entityName: String): T =
+    mapper(entityStr).getOrElse(throw DatabaseException(s"Invalid $entityName in database: $entityStr"))
+
+  def expectValid[T](mapper: String => Option[T], query: String)(implicit ct: ClassTag[T]): T = {
+    fromStringOrThrow[T](query, mapper, ct.toString())
+  }
+}
diff --git a/src/test/scala/xyz/driver/core/database/DatabaseTest.scala b/src/test/scala/xyz/driver/core/database/DatabaseTest.scala
index dafcd80..a5c65ea 100644
--- a/src/test/scala/xyz/driver/core/database/DatabaseTest.scala
+++ b/src/test/scala/xyz/driver/core/database/DatabaseTest.scala
@@ -2,13 +2,27 @@ package xyz.driver.core.database
 
 import org.scalatest.{FlatSpec, Matchers}
 import org.scalatest.prop.Checkers
+import xyz.driver.core.rest.errors.DatabaseException
 
 class DatabaseTest extends FlatSpec with Matchers with Checkers {
+  import xyz.driver.core.generators._
   "Date SQL converter" should "correctly convert back and forth to SQL dates" in {
-    import xyz.driver.core.generators.nextDate
-
     for (date <- 1 to 100 map (_ => nextDate())) {
       sqlDateToDate(dateToSqlDate(date)) should be(date)
     }
   }
+
+  "Converter helper methods" should "work correctly" in {
+    object TestConverter extends Converters
+
+    val validLength                       = nextInt(10)
+    val valid                             = nextToken(validLength)
+    val invalid                           = nextToken(validLength + nextInt(10, 1))
+    def mapper(s: String): Option[String] = if (s.length == validLength) Some(s) else None
+
+    TestConverter.fromStringOrThrow(valid, mapper, valid) should be(valid)
+    TestConverter.expectValid(mapper, valid) should be(valid)
+    an[DatabaseException] should be thrownBy TestConverter.fromStringOrThrow(invalid, mapper, invalid)
+  }
+
 }