Add opt-in support for TASTy-MiMa to check Scala 3 compatibility in CI

build.sbt

@@ -187,7 +187,13 @@ lazy val mima = project
   .in(file("mima"))
   .enablePlugins(SbtPlugin)
   .settings(
-    name := "sbt-typelevel-mima"
+    name := "sbt-typelevel-mima",
+    mimaBinaryIssueFilters ++= Seq(
+      ProblemFilters.exclude[IncompatibleResultTypeProblem](
+        "org.typelevel.sbt.TypelevelMimaPlugin.requires"),
+      ProblemFilters.exclude[DirectMissingMethodProblem](
+        "org.typelevel.sbt.TypelevelMimaPlugin.requires")
+    )
   )
   .dependsOn(kernel)
 

ci/src/main/scala/org/typelevel/sbt/TypelevelCiPlugin.scala

@@ -43,6 +43,8 @@ object TypelevelCiPlugin extends AutoPlugin {
       settingKey[Boolean]("Whether to do scalafix check in CI (default: false)")
     lazy val tlCiMimaBinaryIssueCheck =
       settingKey[Boolean]("Whether to do MiMa binary issues check in CI (default: false)")
+    lazy val tlCiTastyMimaCheck =
+      settingKey[Boolean]("Whether to do TASTy-MiMa issues check in CI (default: false)")
     lazy val tlCiDocCheck =
       settingKey[Boolean]("Whether to build API docs in CI (default: false)")
 
@@ -66,6 +68,7 @@ object TypelevelCiPlugin extends AutoPlugin {
     tlCiJavafmtCheck := false,
     tlCiScalafixCheck := false,
     tlCiMimaBinaryIssueCheck := false,
+    tlCiTastyMimaCheck := false,
     tlCiDocCheck := false,
     tlCiDependencyGraphJob := true,
     tlCiForkCondition := "github.event.repository.fork == false",
@@ -129,6 +132,16 @@ object TypelevelCiPlugin extends AutoPlugin {
             ))
         else Nil
 
+      val tastyMima =
+        if (tlCiTastyMimaCheck.value)
+          List(
+            WorkflowStep.Sbt(
+              List("tastyMiMaReportIssues"),
+              name = Some("Check TASTy compatibility"),
+              cond = Some(primaryAxisCond.value)
+            ))
+        else Nil
+
       val doc =
         if (tlCiDocCheck.value)
           List(
@@ -140,7 +153,7 @@ object TypelevelCiPlugin extends AutoPlugin {
           )
         else Nil
 
-      style ++ scalafix ++ test ++ mima ++ doc
+      style ++ scalafix ++ test ++ mima ++ tastyMima ++ doc
     },
     githubWorkflowJavaVersions := Seq(JavaSpec.temurin("8")),
     githubWorkflowAddedJobs ++= {

docs/customization.md

@@ -64,6 +64,7 @@ Both plugins are documented in [**sbt-typelevel-github-actions**](gha.md).
 - `tlCiJavafmtCheck` (setting): Whether to do javafmt check in CI (default: `false`).
 - `tlCiScalafixCheck` (setting): Whether to do scalafix check in CI (default: `false`).
 - `tlCiMimaBinaryIssueCheck` (setting): Whether to do MiMa binary issues check in CI (default: `false`).
+- `tlCiTastyMimaCheck` (setting): Whether to do TASTy-MiMa issues check in CI (default: `false`).
 - `tlCiDocCheck` (setting): Whether to build API docs in CI (default: `false`).
 - `tlCiDependencyGraphJob` (setting): Whether to add a job to submit dependencies to GH (default: `true`).
 - `tlCiForkCondition` (setting): Condition for checking on CI whether this project is a fork of another (default: `github.event.repository.fork == false`).

mima/build.sbt

@@ -1 +1,2 @@
 addSbtPlugin("com.typesafe" % "sbt-mima-plugin" % "1.1.5")
+addSbtPlugin("ch.epfl.scala" % "sbt-tasty-mima" % "1.4.0")

mima/src/main/scala/org/typelevel/sbt/TypelevelMimaPlugin.scala

@@ -20,13 +20,16 @@ import com.typesafe.tools.mima.plugin.MimaPlugin
 import org.typelevel.sbt.kernel.GitHelper
 import org.typelevel.sbt.kernel.V
 import sbt._
+import sbttastymima.TastyMiMaPlugin
 
 import Keys._
 import MimaPlugin.autoImport._
+import TastyMiMaPlugin.autoImport._
+import TypelevelKernelPlugin.autoImport._
 
 object TypelevelMimaPlugin extends AutoPlugin {
 
-  override def requires = MimaPlugin
+  override def requires = TypelevelKernelPlugin && MimaPlugin && TastyMiMaPlugin
 
   override def trigger = allRequirements
 
@@ -85,6 +88,26 @@ object TypelevelMimaPlugin extends AutoPlugin {
         }
       else
         Set.empty
+    },
+    tastyMiMaReportIssues := {
+      if (tlIsScala3.value && publishArtifact.value) tastyMiMaReportIssues.value
+      else ()
+    },
+    tastyMiMaPreviousArtifacts := {
+      if (tlIsScala3.value && publishArtifact.value) {
+        tlMimaPreviousVersions
+          .value
+          .flatMap(v => V(v))
+          .toList
+          .sorted
+          .lastOption
+          .map { v =>
+            projectID.value.withRevision(v.toString).withExplicitArtifacts(Vector.empty)
+          }
+          .toSet
+      } else {
+        Set.empty
+      }
     }
   )