json-search.js

RegExp.escape = function(text) {
   return text.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&");
}
function searchScore(query, data) {
  var query = query.toString().replace(/\s+/g, " ");
  var queryRegEx = new RegExp(RegExp.escape(query), "g");
  function uniqueArray(array) {
    var result = [];
    for(var i in array) {
      if (result.indexOf(array[i]) === -1) {
        result.push(array[i]);
      }
    }
    return result;
  }
  function getScore(data) {
    if (typeof data !== 'object') {
      data = {value: data};
    }

    data.score = 0;
    var words = uniqueArray(query.replace(/\s+/g, ' ').split(/\s/g));

    for(var key in data) {
      var val = data[key].toString();
      var fullMatches = val.match(queryRegEx) || [];
      if (fullMatches && fullMatches.length >= 1) {
         data.score += fullMatches.length;
      } else {
         data.score += words.map(function(str) {
            return (val.match(new RegExp(RegExp.escape(str), "g")) || []).length/words.length*0.9 || 0;
         }).reduce(function(a, b) {
            return a + b;
         });
      }
    }

    return data;
  }
  return arguments.length > 1 ? getScore(data) : getScore;
}

function search(query, rows) {
  return rows.map(searchScore(query)).sort(function(a, b) {
    return a.score < b.score;
  });
}

usage.js

search("test", ["test1", "test2"]);
// => [{"value":"test1","score":1},{"value":"test2","score":1}]

search("test this", [{
  key: "value",
  anotherKey: "test"
}, {
  key: "test this",
  anotherKey: "this test"
}]);
// => [{"key":"test this","anotherKey":"this test","score":1.9},{"key":"value","anotherKey":"test","score":0.45}]