Function Outlining

Description

Function Outlining transforms a single or group of statements into a new function declaration.

Code Annotation Example

// @jscrambler define functionOutlining {features: [opaqueFunctions]} as fo
// @jscrambler enable fo

Examples

Consider the following function declaration:

function addPrefix (array, prefix) {
  var i = array.length - 1;
  for (i; i >= 0; i--) {
    array[i] = prefix + array[i];
  }
}

After transformation the addPrefix function will depend on functions to evaluate expressions that were previously inline:

var o = function (D) {
    return {
        M: function () {
            var V, W = arguments;
            switch (D) {
            case 0:
                V = W[0] - W[1];
                break;
            case 1:
                V = W[1] + W[0];
                break;
            }
            return V;
        },
        E: function (v) {
            D = v;
        }
    };
}();

function addPrefix(array, prefix) {
    var i;
    o.E(0);
    i = o.M(array.length, 1);
    for (i; i >= 0; i--) {
        o.E(1);
        array[i] = o.M(array[i], prefix);
    }
}

Function Outlining also has the parameter opaqueFunctions that will difficult determining which function will be executed.

Option Types

Name	Required	Default Value	Description
freq	No	1	Probability of applying the transformation when the node allows for the transformation to happen.
features	No	[]	List of available features

Features

Name	Description
opaqueFunctions	Opaque Functions conceals which functions generated by function outlining are executed

Browser Compatibility

Browser	Compatible Versions	Tested Versions	Notes
Chrome	80+	80+
Firefox	90+	90+
Internet Explorer	8+	8+
Microsoft Edge	116+	116+
Safari	13.1+	13.1+

API Parameters

Example:

{
  "keys": {
    "accessKey": "XXXXXX",
    "secretKey": "YYYYYY"
  },
  "applicationId": "ZZZZZZ",
  "params": [
    {
      "name": "functionOutlining",
      "options": {
        "features": []
      }
    }
  ]
}