tsv-to-json.js

//var tsv is the TSV file with headers
function tsvJSON(tsv){
 
  var lines=tsv.split("\n");
 
  var result = [];
 
  var headers=lines[0].split("\t");
 
  for(var i=1;i<lines.length;i++){
 
	  var obj = {};
	  var currentline=lines[i].split("\t");
 
	  for(var j=0;j<headers.length;j++){
		  obj[headers[j]] = currentline[j];
	  }
 
	  result.push(obj);
 
  }
  
  //return result; //JavaScript object
  return JSON.stringify(result); //JSON
}

On line 4, I am using tsv.trim().split("\n"); to ensure there is not an empty object at the end.