Add a combine method to ConfigErrors

vlovgr · Aug 2, 2018 · 0c3f152 · 0c3f152
1 parent 9a3457e
commit 0c3f152
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diff --git a/modules/cats/shared/src/main/scala/ciris/cats/api/CirisInstancesForCats.scala b/modules/cats/shared/src/main/scala/ciris/cats/api/CirisInstancesForCats.scala
@@ -1,6 +1,7 @@
 package ciris.cats.api
 
 import cats.Show
+import cats.Semigroup
 import ciris._
 
 trait CirisInstancesForCats {
@@ -30,4 +31,9 @@ trait CirisInstancesForCats {
 
   implicit def showSecret[A]: Show[Secret[A]] =
     Show.fromToString
+
+  implicit val semigroupConfigErrors: Semigroup[ConfigErrors] = new Semigroup[ConfigErrors] {
+    def combine(first: ConfigErrors, second: ConfigErrors) =
+      ConfigErrors.combine(first, second)
+  }
 }
diff --git a/modules/core/shared/src/main/scala/ciris/ConfigErrors.scala b/modules/core/shared/src/main/scala/ciris/ConfigErrors.scala
@@ -170,4 +170,20 @@ object ConfigErrors {
     */
   def right[A](value: A): Either[ConfigErrors, A] =
     Right(value)
+
+  /**
+   * Creates a new [[ConfigErrors]] instance containing all the errors of
+   * both `first` and `second`, in that order.
+   *
+   * @param first the first [[ConfigErrors]]
+   * @param second the second [[ConfigErrors]]
+    * @return a new [[ConfigErrors]] instance
+    * @example {{{
+    * scala> ConfigErrors.combine(ConfigErrors(ConfigError("error1")), ConfigErrors(ConfigError("error2")))
+    * res0: ConfigErrors = ConfigErrors(ConfigError(error1), ConfigError(error2))
+    * }}}
+   */
+  def combine(first: ConfigErrors, second: ConfigErrors): ConfigErrors =
+    new ConfigErrors(first.toVector ++ second.toVector)
+
 }
diff --git a/tests/shared/src/test/scala/ciris/cats/api/CirisInstancesForCatsSpec.scala b/tests/shared/src/test/scala/ciris/cats/api/CirisInstancesForCatsSpec.scala
@@ -75,5 +75,20 @@ final class CirisInstancesForCatsSpec extends PropertySpec {
         ) shouldBe "Secret(40bd001)"
       }
     }
+
+    "providing Semigroup instances" should {
+      "be able to provide all required instances" in {
+        import _root_.cats.Semigroup
+        import _root_.cats.implicits._
+        import ciris._
+        import ciris.api._
+        import ciris.cats._
+
+        val first = ConfigErrors(ConfigError("a"), ConfigError("b"))
+        val second = ConfigErrors(ConfigError("c"), ConfigError("d"))
+        val combined = Semigroup[ConfigErrors].combine(first, second)
+        combined.messages shouldBe ConfigErrors(ConfigError("a"), ConfigError("b"), ConfigError("c"), ConfigError("d")).messages
+      }
+    }
   }
 }