N/task Module
MapReduceScriptTaskStatus.stage
Property Description: Current stage of processing for a map/reduce script deployment instance. Returns a task.MapReduceStage enum value. For general information about map/reduce stages, see Map/Reduce Key Concepts. For information about the execution of map/reduce scripts, see SuiteScript 2.0 Map/Reduce Script Submission.
Type: string (read-only)
Supported Script Types: Server scripts For more information, see SuiteScript 2.0 Script Types.
Module: N/task Module
Since: 2015.2
Search NetSuite - https://system.netsuite.com/app/help/helpcenter.nl?search=MapReduceScriptTaskStatus.stage

// Code Example 1

//Add additional code

//...

var summary = task.checkStatus(scriptTaskId);

if (summary.stage === task.MapReduceStage.SUMMARIZE)

    log.audit({

    details: 'Almost done...'

    });

//...

//Add additional code



//SOURCE: https://system.netsuite.com/app/help/helpcenter.nl?fid=section_460753112791.html