Add integration test to run scala nightly version

Author: lwronski

modules/integration/src/test/scala/scala/cli/integration/RunTests212.scala

@@ -31,4 +31,21 @@ class RunTests212 extends RunTestDefinitions(
       )
     }
   }
+  test("2.12.nightly") {
+    TestInputs(os.rel / "sample.sc" -> "println(util.Properties.versionNumberString)").fromRoot {
+      root =>
+        val res =
+          os.proc(
+            TestUtil.cli,
+            "run",
+            ".",
+            "-S",
+            "2.12.nightly",
+            TestUtil.extraOptions
+          )
+            .call(cwd = root)
+        val version = res.out.trim()
+        expect(version.startsWith("2.12"))
+    }
+  }
 }

modules/integration/src/test/scala/scala/cli/integration/RunTests213.scala

@@ -1,7 +1,27 @@
 package scala.cli.integration
 
+import com.eed3si9n.expecty.Expecty.expect
+
 // format: off
 class RunTests213 extends RunTestDefinitions(
   scalaVersionOpt = Some(Constants.scala213)
-)
+){
 // format: on
+  test("2.13.nightly") {
+    TestInputs(os.rel / "sample.sc" -> "println(util.Properties.versionNumberString)").fromRoot {
+      root =>
+        val res =
+          os.proc(
+            TestUtil.cli,
+            "run",
+            ".",
+            "-S",
+            "2.13.nightly",
+            TestUtil.extraOptions
+          )
+            .call(cwd = root)
+        val version = res.out.trim()
+        expect(version.startsWith("2.13"))
+    }
+  }
+}

modules/integration/src/test/scala/scala/cli/integration/RunTestsDefault.scala

@@ -47,4 +47,21 @@ class RunTestsDefault extends RunTestDefinitions(scalaVersionOpt = None) {
       archLinuxTest()
     }
 
+  test("3.nightly") { // should run code using scala 3 nightly version
+    TestInputs(os.rel / "sample.sc" -> """println("Hello World")""").fromRoot {
+      root =>
+        val res =
+          os.proc(
+            TestUtil.cli,
+            "run",
+            ".",
+            "-S",
+            "3.nightly",
+            TestUtil.extraOptions
+          )
+            .call(cwd = root)
+        expect(res.out.trim() == "Hello World")
+    }
+  }
+
 }