Variable not being reset to empty state

Queries and Resources
1

I have a variable, dealsWithIssue, that I'd like to set to an empty dictionary with each invocation of a Run JS Code resource. My JS code looks like the following

function saveDealIssue(dealId, issue) {
  // load all issues
  const dwi = dealsWithIssues.value
  const issuesForDeal = dwi[dealId]
  if (!deal) {
    dealsWithIssues.setValue({...dwi, [dealId]: [issue]})
  } else {
    dealsWithIssues.setValue({...dwi, [dealId]: [...issuesForDeal, issue]})
  }
}

function doStuff() {
   // ...
   saveDealIssue(123, 'lol')
   // ....
}


dealsWithIssues.setValue({})
doStuff()

I find that if I run this multiple times, the state for dealsWithIssues goes from
{123: [lol]} to {123: [lol, lol]}, etc... (where new entries keep being added with each subsequent invocation)

How can I correctly reset the state of my variable prior to calling doStuff?