Added tests

main/eval/test/src/mill/eval/TaskTests.scala

@@ -2,7 +2,7 @@ package mill.eval
 
 import utest._
 import mill.T
-import mill.define.{Module, Worker}
+import mill.define.{Module, Task, Worker}
 import mill.testkit.UnitTester
 import mill.testkit.UnitTester.Result
 import mill.testkit.TestBaseModule
@@ -121,6 +121,16 @@ trait TaskTests extends TestSuite {
       superBuildTargetOverrideWithInputCount
     }
 
+    def sometimesFailing(fail: Boolean): Task[String] = T.task {
+      if (!fail) mill.api.Result.Success("Success")
+      else mill.api.Result.Failure("Failure")
+    }
+
+    def sometimesFailingWithException(fail: Boolean): Task[String] = T.task {
+      if (!fail) "Success"
+      else T.fail("Failure")
+    }
+
     // Reproduction of issue https://github.com/com-lihaoyi/mill/issues/2958
     object repro2958 extends Module {
       val task1 = T.task { "task1" }
@@ -258,6 +268,23 @@ trait TaskTests extends TestSuite {
     test("duplicateTaskInResult-issue2958") - withEnv { (build, check) =>
       check(build.repro2958.command()) ==> Right(Result("task1,task1", 3))
     }
+
+    test("sometimeFailing") {
+      test("success") - withEnv { (build, check) =>
+        check(build.sometimesFailing(false)) ==> Right(Result("Success", 0))
+      }
+      test("failure") - withEnv { (build, check) =>
+        check(build.sometimesFailing(true)) ==> Left(mill.api.Result.Failure("Failure", None))
+      }
+    }
+    test("sometimeFailingWithException") {
+      test("success") - withEnv { (build, check) =>
+        check(build.sometimesFailingWithException(false)) ==> Right(Result("Success", 0))
+      }
+      test("failure") - withEnv { (build, check) =>
+        check(build.sometimesFailingWithException(true)) ==> Left(mill.api.Result.Failure("Failure", None))
+      }
+    }
   }
 
 }