Generating javascript programs from a set of characters

generate-programs.js

"use strict"
const chars='+[]'.split('')
let pastStrings=[...chars]
const outs=[]
const num = 12 // number of characters to try appending
let best = null
mainLoop:
for(let i=0;i<num;++i){
  let newStrings=[]
  for(const preStr of pastStrings){
    for(const c of chars){
      const newStr = preStr + c
      newStrings.push(newStr)
      try {
        const val = eval(newStr)
        outs.push([newStr, val])
        console.log(`${newStr} -> ${val}`)
        if(val === 1){
          best = newStr
          break mainLoop
        }
      } catch (err){
      }
    }
  }
  pastStrings=newStrings
}
console.log(`${outs.length} valid program outputs`)
if(best){
  console.log('Found: ', best)
}