andyczerwonka · June 13, 2020 14:25 · Jun 13, 2020
diff --git a/BusinessRuleThoughts.scala b/BusinessRuleThoughts.scala
@@ -0,0 +1,47 @@
+package io.citrine.orion.core.domain
+
+import io.citrine.testing.BaseUnitTest
+
+import scala.collection.mutable.ListBuffer
+
+class BusinessRuleTest extends BaseUnitTest {
+
+  trait StatusInfo {
+    def write(msg: String)
+    def msgs(): Seq[String]
+  }
+
+  class StatusInfoWriter extends StatusInfo {
+    private val buffer = ListBuffer[String]()
+    override def write(msg: String): Unit = buffer += msg
+    override def msgs(): List[String] = buffer.toList
+  }
+
+  implicit val statusInfo = new StatusInfoWriter
+
+  case class Row(contents: String)
+
+  def rule(desc: String)(predicate: => Boolean)(implicit statusInfo: StatusInfo): Boolean = {
+    val ex = predicate
+    val prefix = if (ex) "Passed:" else "Failed:"
+    statusInfo.write(s"$prefix $desc")
+    ex
+  }
+
+  test("allow less than 100 rows") {
+    val rows = List(Row("1"))
+    rule("Limit rows to 100") {
+      rows.length < 100
+    } shouldBe true
+    statusInfo.msgs contains ("Passed: Limit rows to 100")
+  }
+
+  test("fail when rows > 100") {
+    val rows = for (i <- 0 to 101) yield Row(s"$i")
+    rule("Limit rows to 100") {
+      rows.length < 100
+    } shouldBe false
+    statusInfo.msgs contains ("Failed: Limit rows to 100")
+  }
+
+}