tests: Extract RemigrateTest

* Speed up parallel test execution by extracting a rather long-running
  test into a separate test class (RemigrateTest).
* RemigrateTest: remove output forwarding.

src/test/kotlin/test/migration/RemigrateTest.kt

@@ -0,0 +1,76 @@
+package test.migration
+
+import org.gradle.testkit.runner.GradleRunner
+import org.gradle.testkit.runner.TaskOutcome
+import org.junit.Assert.assertEquals
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.rules.TemporaryFolder
+import support.extractTestProject
+import java.io.File
+
+class RemigrateTest {
+    @Rule
+    @JvmField
+    val testProjectDir: TemporaryFolder = TemporaryFolder()
+    private lateinit var settingsFile: File
+    private lateinit var buildFile: File
+    private lateinit var mpsTestPrjLocation: File
+
+    @Before
+    fun setup() {
+        settingsFile = testProjectDir.newFile("settings.gradle.kts")
+        settingsFile.writeText(
+            """
+            rootProject.name = "hello-world"
+        """.trimIndent()
+        )
+        buildFile = testProjectDir.newFile("build.gradle.kts")
+        mpsTestPrjLocation = testProjectDir.newFolder("mps-prj")
+        extractProject("test-project")
+    }
+
+    private fun extractProject(name: String) = extractTestProject(name, mpsTestPrjLocation)
+
+    @Test
+    fun `Remigrate task works`() {
+        buildFile.writeText(
+            """
+                import de.itemis.mps.gradle.tasks.Remigrate
+
+                plugins {
+                    id("de.itemis.mps.gradle.common")
+                }
+
+                repositories {
+                    mavenCentral()
+                    maven("https://artifacts.itemis.cloud/repository/maven-mps")
+                }
+
+                val mps = configurations.create("mps")
+                dependencies {
+                    mps("com.jetbrains:mps:2021.3.2")
+                }
+
+                val resolveMps by tasks.registering(Sync::class) {
+                    from(Callable { zipTree(mps.singleFile) })
+                    into(layout.buildDirectory.dir("mps"))
+                }
+
+                val remigrate by tasks.registering(Remigrate::class) {
+                    projectDirectories.from("$mpsTestPrjLocation")
+                    mpsHome.set(layout.dir(resolveMps.map { it.destinationDir }))
+                }
+            """.trimIndent()
+        )
+
+        val result = gradleRunner().withArguments("remigrate").build()
+
+        assertEquals(TaskOutcome.SUCCESS, result.task(":remigrate")?.outcome)
+    }
+
+    private fun gradleRunner(): GradleRunner = GradleRunner.create()
+        .withProjectDir(testProjectDir.root)
+        .withPluginClasspath()
+}

src/test/kotlin/test/migration/RunMigrationsTest.kt

@@ -211,43 +211,6 @@ class RunMigrationsTest {
         assertEquals(TaskOutcome.SUCCESS, result.task(":migrate")?.outcome)
     }
 
-    @Test
-    fun `Remigrate task works`() {
-        buildFile.writeText(
-            """
-                import de.itemis.mps.gradle.tasks.Remigrate
-
-                plugins {
-                    id("de.itemis.mps.gradle.common")
-                }
-
-                repositories {
-                    mavenCentral()
-                    maven("https://artifacts.itemis.cloud/repository/maven-mps")
-                }
-
-                val mps = configurations.create("mps")
-                dependencies {
-                    mps("com.jetbrains:mps:2021.3.2")
-                }
-
-                val resolveMps by tasks.registering(Sync::class) {
-                    from(Callable { zipTree(mps.singleFile) })
-                    into(layout.buildDirectory.dir("mps"))
-                }
-
-                val remigrate by tasks.registering(Remigrate::class) {
-                    projectDirectories.from("$mpsTestPrjLocation")
-                    mpsHome.set(layout.dir(resolveMps.map { it.destinationDir }))
-                }
-            """.trimIndent()
-        )
-
-        val result = gradleRunner().withArguments("remigrate").forwardOutput().build()
-
-        assertEquals(TaskOutcome.SUCCESS, result.task(":remigrate")?.outcome)
-    }
-
     private fun gradleRunner(): GradleRunner = GradleRunner.create()
         .withProjectDir(testProjectDir.root)
         .withPluginClasspath()