TypeError: Cannot read property 'length' of undefined

[RichardHoOoOo]

TypeError: Cannot read property 'length' of undefined
at generateFunctionParams (/Users/jiajunhu/Google_Drive/Research/ICSE2020/jalangi2/node_modules/esotope/esotope.js:651:34)
at generateFunctionBody (/Users/jiajunhu/Google_Drive/Research/ICSE2020/jalangi2/node_modules/esotope/esotope.js:705:9)
at Object.generateMethodDefinition [as MethodDefinition] (/Users/jiajunhu/Google_Drive/Research/ICSE2020/jalangi2/node_modules/esotope/esotope.js:1234:13)
at Object.generateClassBody [as ClassBody] (/Users/jiajunhu/Google_Drive/Research/ICSE2020/jalangi2/node_modules/esotope/esotope.js:1569:34)
at Object.generateClassDeclaration [as ClassDeclaration] (/Users/jiajunhu/Google_Drive/Research/ICSE2020/jalangi2/node_modules/esotope/esotope.js:1591:32)
at Object.generateBlockStatement [as BlockStatement] (/Users/jiajunhu/Google_Drive/Research/ICSE2020/jalangi2/node_modules/esotope/esotope.js:1526:36)
at stmtToJs (/Users/jiajunhu/Google_Drive/Research/ICSE2020/jalangi2/node_modules/esotope/esotope.js:2143:28)
at Object.generateTryStatement [as TryStatement] (/Users/jiajunhu/Google_Drive/Research/ICSE2020/jalangi2/node_modules/esotope/esotope.js:1858:26)
at Object.generateBlockStatement [as BlockStatement] (/Users/jiajunhu/Google_Drive/Research/ICSE2020/jalangi2/node_modules/esotope/esotope.js:1526:36)
at Object.generateWhileStatement [as WhileStatement] (/Users/jiajunhu/Google_Drive/Research/ICSE2020/jalangi2/node_modules/esotope/esotope.js:2103:32)

Test sample:

<script type="text/javascript">
	
	class myDate extends Date {
		
		constructor() {
			super();
		}

		
		getFormattedDate() {
			var months = ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'];
			return this.getDate() + "-" + months[this.getMonth()] + "-" + this.getFullYear();
		}
	}

	

function foo(){
		return "foo ";
	}

	function bar(){
		return "bar ";
	}

	function test() {
		var d = new myDate();
  s = ""
		s = d.getFormattedDate();
		for (var i = 0; i < 10; i++){
			if (i%2 === 0){
				s += foo();
			} else {
				s += bar();
			}
		}
		return s;
	}	
</script>

[amiduai]

Same here, anyone has solved it ?