feature: emit nullable path in tuples

removed test as hang the build after rebase
instead use integration test

Signed-off-by: Jorge Aguilera <jorge.aguilera@seqera.io>

Author: jorgeaguileraseqera

modules/nextflow/src/test/groovy/nextflow/script/InputNullablePathTest.groovy

@@ -519,7 +519,7 @@ class ScriptDslTest extends Dsl2Spec {
     def 'should fail because process is not defined'() {
         when:
         dsl_eval(
-                '''
+        '''
         process sleeper {
             exec:
             """

modules/nextflow/src/test/groovy/nextflow/script/OutputNullablePathTest.groovy

@@ -203,22 +203,21 @@ class ScriptRunnerTest extends Specification {
 
         def runner = new TestScriptRunner(session)
 
-        def randomVar = Nextflow.randomString(5,false)
-        def script = """
+        def script = '''
             process test {
                 script:
-                "echo \$$randomVar"
+                "echo $HELLO"
             }
 
-            """
-        println script
+            '''
+
         when:
         runner.setScript(script).execute()
         then:
         session.fault.error instanceof ProcessUnrecoverableException
         session.fault.error.cause instanceof MissingPropertyException
-        session.fault.error.cause.message =~ /Unknown variable '$randomVar' -- .*/
-        session.fault.report =~ /No such variable: $randomVar -- .*/
+        session.fault.error.cause.message =~ /Unknown variable 'HELLO' -- .*/
+        session.fault.report =~ /No such variable: HELLO -- .*/
 
     }