Restore returning of functional types from repl eval

add tests for the broken case as well for the return value representation
#KT-29490 fixed

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/repl/GenericReplEvaluator.kt

@@ -110,7 +110,7 @@ open class GenericReplEvaluator(
 
             val resultFieldName = scriptResultFieldName(compileResult.lineId.no)
             val resultField = scriptClass.getDeclaredField(resultFieldName).apply { isAccessible = true }
-            val resultValue: Any? = if (!compileResult.isFunctionType) resultField.get(scriptInstance) else "<function>"
+            val resultValue: Any? = resultField.get(scriptInstance)
 
             return if (compileResult.hasResult) ReplEvalResult.ValueResult(resultFieldName, resultValue, compileResult.type)
             else ReplEvalResult.UnitResult()

compiler/testData/repl/functionResult.repl

@@ -0,0 +1,5 @@
+>>> { 1 + 2 }
+() -> kotlin.Int
+>>> val x = { "abc" }
+>>> x
+() -> kotlin.String

compiler/tests/org/jetbrains/kotlin/repl/ReplInterpreterTestGenerated.java

@@ -84,6 +84,11 @@ public class ReplInterpreterTestGenerated extends AbstractReplInterpreterTest {
         runTest("compiler/testData/repl/functionReferencesPrev.repl");
     }
 
+    @TestMetadata("functionResult.repl")
+    public void testFunctionResult() throws Exception {
+        runTest("compiler/testData/repl/functionResult.repl");
+    }
+
     @TestMetadata("imports.repl")
     public void testImports() throws Exception {
         runTest("compiler/testData/repl/imports.repl");

libraries/examples/kotlin-jsr223-local-example/src/test/kotlin/org/jetbrains/kotlin/script/jsr223/KotlinJsr223ScriptEngineIT.kt

@@ -233,6 +233,17 @@ obj
         Assert.assertTrue("eval in eval is too long: ${times.joinToString { "(${it.first.ms()}, ${it.second.ms()})" }} (expecting no more than 5x difference)",
                 adjustedMaxDiff.third < 20 /* assuming it measurement error */ || adjustedMaxDiff.first * 5 > adjustedMaxDiff.second )
     }
+
+    @Test
+    fun `kotlin script evaluation should support functional return types`() {
+        val scriptEngine = KotlinJsr223JvmLocalScriptEngineFactory().scriptEngine
+
+        val script = "{1 + 2}"
+        val result = scriptEngine.eval(script)
+
+        Assert.assertTrue(result is Function0<*>)
+        Assert.assertEquals(3, (result as Function0<*>).invoke())
+    }
 }
 
 fun assertThrows(exceptionClass: Class<*>, body: () -> Unit) {