Enable MiMa

build.sbt

@@ -12,11 +12,10 @@ val pekkoHttpVersion = "1.0.0"
 val jawnVersion      = "1.5.0"
 val scalaTestVersion = "3.2.16"
 
-ThisBuild / crossScalaVersions   := Seq(scala212Version, scala213Version, scala3Version)
-ThisBuild / scalaVersion         := scala213Version
-ThisBuild / organization         := "org.mdedetrich"
-ThisBuild / mimaFailOnNoPrevious := false // Set this to true when we start caring about binary compatibility
-ThisBuild / versionScheme        := Some(VersionScheme.EarlySemVer)
+ThisBuild / crossScalaVersions := Seq(scala212Version, scala213Version, scala3Version)
+ThisBuild / scalaVersion       := scala213Version
+ThisBuild / organization       := "org.mdedetrich"
+ThisBuild / versionScheme      := Some(VersionScheme.EarlySemVer)
 
 lazy val streamJson = project
   .in(file("stream-json"))
@@ -65,9 +64,11 @@ lazy val parent = project
   .dependsOn(httpJson, httpCirce)
   .aggregate(streamJson, httpJson, streamCirce, httpCirce, tests)
   .settings(
-    publish / skip       := true,
-    publishSigned / skip := true,
-    publishLocal / skip  := true
+    name                  := "pekko-streams-circe",
+    mimaPreviousArtifacts := Set.empty,
+    publish / skip        := true,
+    publishSigned / skip  := true,
+    publishLocal / skip   := true
   )
 
 lazy val tests = project
@@ -85,6 +86,7 @@ lazy val tests = project
     publishSigned / skip := true,
     publishLocal / skip  := true
   )
+  .disablePlugins(MimaPlugin)
 
 ThisBuild / scalacOptions ++= Seq(
   "-release:8",

project/Mima.scala

@@ -0,0 +1,35 @@
+import com.typesafe.tools.mima.plugin.MimaKeys._
+import com.typesafe.tools.mima.plugin.MimaPlugin
+import sbt.{AutoPlugin, CrossVersion}
+import sbt.Keys._
+import sbt._
+
+import scala.collection.immutable
+
+object Mima extends AutoPlugin {
+  override def requires = MimaPlugin
+
+  override def trigger = allRequirements
+
+  private def expandVersions(major: Long, minor: Long, patches: immutable.Seq[Int]): immutable.Seq[String] =
+    patches.map(patch => s"$major.$minor.$patch")
+  private def previousArtifacts(projectName: String, organization: String, version: String): Set[sbt.ModuleID] = {
+    val Some((major, minor)) = CrossVersion.partialVersion(version)
+    val currentPatchVersion  = version.split("\\.").last
+    val stripRegex           = """(\d+)(.*)""".r
+
+    val currentPatchVersionStripped = currentPatchVersion match {
+      case stripRegex(v, _) => v.toInt
+    }
+
+    if (currentPatchVersionStripped == 0)
+      Set(organization %% projectName % s"$major.$minor.0")
+    else
+      expandVersions(major, minor, 0 until currentPatchVersionStripped).map(v => organization %% projectName % v).toSet
+  }
+
+  override lazy val projectSettings = Seq(
+    mimaReportSignatureProblems := true,
+    mimaPreviousArtifacts       := previousArtifacts(name.value, organization.value, version.value)
+  )
+}