Add failing test for #175

slick-testkit/src/main/scala/com/typesafe/slick/testkit/tests/CountTest.scala

@@ -28,4 +28,38 @@ class CountTest extends TestkitTest[RelationalTestDB] {
     val q4 = testTable.take(2).length
     assertEquals(2, q4.run)
   }
+
+  def testJoin {
+    class Categories(tag: Tag) extends Table[(Int, String)](tag, "cat_j") {
+      def id = column[Int]("id")
+      def name = column[String]("name")
+      def * = (id, name)
+    }
+    val categories = TableQuery[Categories]
+
+    class Posts(tag: Tag) extends Table[(Int, String, Int)](tag, "posts_j") {
+      def id = column[Int]("id", O.PrimaryKey, O.AutoInc)
+      def title = column[String]("title")
+      def category = column[Int]("category")
+      def * = (id, title, category)
+    }
+    val posts = TableQuery[Posts]
+
+    (categories.ddl ++ posts.ddl).create
+    categories ++= Seq((1, "Scala"), (2, "JVM"), (3, "Java"), (4, "Erlang"), (5, "Haskell"))
+    posts ++= Seq((1, "Shiny features", 1), (2, "HotSpot", 2))
+
+    val joinedQuery = for {
+      c <- categories
+      p <- posts
+      if p.category === c.id
+    } yield (c, p)
+
+    val q1 = joinedQuery.length
+    assertEquals(2, q1.run)
+
+    val q2 = Query(joinedQuery.length)
+    assertEquals(Vector(2), q2.run)
+
+  }
 }