Improve handling of surprises in the migrations folder

src/main/scala/com/chrisomeara/pillar/Registry.scala

@@ -31,6 +31,7 @@ object Registry {
     files
       .filterNot(file => file.isDirectory)
       .filter(file => file.exists())
+      .filterNot(file => file.isHidden)
   }
 
   private def parseMigrationsInFiles(files: Seq[File]): Seq[Migration] = {
@@ -41,6 +42,9 @@ object Registry {
         val stream = new FileInputStream(file)
         try {
           parser.parse(stream)
+        } catch {
+          case e: Exception =>
+            throw new RuntimeException(s"Error parsing migration file ${file}: ${e.getMessage}", e)
         } finally {
           stream.close()
         }
@@ -51,7 +55,7 @@ object Registry {
     if (!directory.isDirectory)
       return List.empty
 
-    parseMigrationsInFiles(directory.listFiles())
+    parseMigrationsInFiles(filterExisting(directory.listFiles()))
   }
 }
 

src/test/resources/pillar/migrations/faker/.a-dotfile

@@ -0,0 +1 @@
+garbage

src/test/resources/pillar/migrations/garbage.cql

@@ -0,0 +1 @@
+��?{u*�?

src/test/scala/com/chrisomeara/pillar/RegistrySpec.scala

@@ -64,6 +64,15 @@ class RegistrySpec extends FunSpec with BeforeAndAfter with ShouldMatchers with
           registry.all.size should equal(0)
         }
       }
+
+      describe("with a file that contains garbage"){
+        it("throws an exception with a meaningful message") {
+          val exception = intercept[RuntimeException] {
+            Registry.fromFiles(Seq(new File("src/test/resources/pillar/migrations/garbage.cql")))
+          }
+          exception.getMessage should equal("Error parsing migration file src/test/resources/pillar/migrations/garbage.cql: Input length = 1")
+        }
+      }
     }
 
     describe("with a reporter parameter") {