Allow using labels with any type having a Show instance

permutive-engineering · Aug 18, 2023 · 0998f43 · 0998f43
1 parent 4aeab3f
commit 0998f43
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Showing 3 changed files with 18 additions and 7 deletions.
diff --git a/core/src/main/scala/prometheus4cats/Label.scala b/core/src/main/scala/prometheus4cats/Label.scala
@@ -16,6 +16,9 @@
 
 package prometheus4cats
 
+import cats.Show
+import cats.syntax.all._
+
 import prometheus4cats.internal.LabelNameFromStringLiteral
 import prometheus4cats.internal.Refined
 import prometheus4cats.internal.Refined.Regex
@@ -37,4 +40,12 @@ object Label {
 
   }
 
+  final class Value private (val value: String) extends AnyVal
+
+  object Value {
+
+    implicit def fromShow[A: Show](a: A): Value = new Value(a.show)
+
+  }
+
 }
diff --git a/core/src/main/scala/prometheus4cats/internal/package.scala b/core/src/main/scala/prometheus4cats/internal/package.scala
@@ -449,11 +449,11 @@ class LabelledMetricDsl[F[_], A, T, L[_[_], _, _]] private[internal] (
     new LabelsApply[F, A, T, B, L] {
 
       override def apply[C](
-          labels: (Label.Name, B => String)*
+          labels: (Label.Name, B => Label.Value)*
       )(implicit initLast: InitLast.Aux[T, B, C]): LabelledMetricDsl[F, A, C, L] = new LabelledMetricDsl(
         makeMetric,
         labelNames ++ labels.map(_._1),
-        c => f(initLast.init(c)) ++ labels.map(_._2(initLast.last(c)))
+        c => f(initLast.init(c)) ++ labels.map(_._2(initLast.last(c)).value)
       )
 
     }
@@ -498,13 +498,13 @@ object LabelledMetricDsl {
     override def labels[B]: LabelsApply.WithCallbacks[F, A, A0, T, B, L] =
       new LabelsApply.WithCallbacks[F, A, A0, T, B, L] {
 
-        override def apply[C](labels: (Label.Name, B => String)*)(implicit
+        override def apply[C](labels: (Label.Name, B => Label.Value)*)(implicit
             initLast: InitLast.Aux[T, B, C]
         ): WithCallbacks[F, A, A0, C, L] = new WithCallbacks(
           makeMetric,
           makeCallback,
           labelNames ++ labels.map(_._1),
-          c => f(initLast.init(c)) ++ labels.map(_._2(initLast.last(c)))
+          c => f(initLast.init(c)) ++ labels.map(_._2(initLast.last(c)).value)
         )
 
       }
@@ -584,7 +584,7 @@ object LabelApply {
 
 abstract class LabelsApply[F[_], A, T, B, L[_[_], _, _]] {
 
-  def apply[C](labels: (Label.Name, B => String)*)(implicit
+  def apply[C](labels: (Label.Name, B => Label.Value)*)(implicit
       initLast: InitLast.Aux[T, B, C]
   ): LabelledMetricDsl[F, A, C, L]
 
@@ -594,7 +594,7 @@ object LabelsApply {
 
   abstract class WithCallbacks[F[_], A, A0, T, B, L[_[_], _, _]] extends LabelsApply[F, A, T, B, L] {
 
-    def apply[C](labels: (Label.Name, B => String)*)(implicit
+    def apply[C](labels: (Label.Name, B => Label.Value)*)(implicit
         initLast: InitLast.Aux[T, B, C]
     ): LabelledMetricDsl.WithCallbacks[F, A, A0, C, L]
 

diff --git a/core/src/test/scala/test/MetricsFactoryDslTest.scala b/core/src/test/scala/test/MetricsFactoryDslTest.scala
@@ -78,7 +78,7 @@ object MetricsFactoryDslTest {
   longCounterBuilder.build
   longCounterBuilder
     .label[String]("label1")
-    .labels[(Int, BigInteger)](("label2", _._1.toString()), ("label3", _._2.toString()))
+    .labels[(Int, BigInteger)](("label2", _._1), ("label3", _._2.toString()))
     .build
     .map(_.inc(("dsfsf", (1, BigInteger.ONE))))
   longCounterBuilder.unsafeLabels(Label.Name("label1"), Label.Name("label2")).build