SafeRange bug restricts certain ranges

[ksritharan]

Version

• Phaser Version: 3.55.2

• Operating system:

• Browser:

Description

The condition startIndex + endIndex > len, in SafeRange.js is not necessary, and it restricts valid ranges.

/* src/utils/arrays/SafeRange.js */
var SafeRange = function (array, startIndex, endIndex, throwError)
{
    var len = array.length;

    if (startIndex < 0 ||
        startIndex > len ||
        startIndex >= endIndex ||
        endIndex > len ||
        startIndex + endIndex > len)
    {

The purpose of this function is to validate ranges in the form of [startIndex, endIndex). Where [ includes startIndex and ) excludes endIndex.
The fix will allow the following ranges to be validated:

[n, Array.length), n = {1, ..., Array.length-1}, Array.length > 1
[n, m), n = {1, ..., Array.length - 1}, m = {n+1, ..., Array.length}, Array.length > 1

For example,

var arr = [0, 1, 2, 3, 4];
console.log(Phaser.Utils.Array.SafeRange(arr, 0, arr.length)); // true, since [0, 5) is a valid range for arr that gives [0, 1, 2, 3, 4]
console.log(Phaser.Utils.Array.SafeRange(arr, 1, arr.length)); // false, but should be true since [1, 5) is a valid range for arr that gives [1, 2, 3, 4]
console.log(Phaser.Utils.Array.SafeRange(arr, 2, 4)); // false, but should be true since [2, 4) is a valid range for arr that gives [2, 3]

It restricts the following static methods in Phaser.Utils.Arrays: CountAllMatching, EachInRange, GetAll, GetFirst, RemoveBetween, SetAll.
The proposed fix will allow these methods to be able to operate on the aforementioned ranges.
For example, this code snippet demonstrates the change for GetAll (Phaser.GameObjects.Group::getMatching)
https://jsfiddle.net/z7w96k53/1/

  create() {
    var gameObjects = [];
    for (let i = 0; i < 5; i++) {
      var gameObject = new Phaser.GameObjects.Container(this);
      gameObject.setData('num', i);
      gameObjects.push(gameObject);
    }
    var group = new Phaser.GameObjects.Group(this, gameObjects);
    var newGroup = new NewGroup(this, gameObjects)
    console.log("Before");
    console.log(group.getMatching('active', true, 0).map(element => element.getData('num'))); // [0, 1, 2, 3, 4]
    console.log(group.getMatching('active', true, 1).map(element => element.getData('num'))); // []
    console.log(group.getMatching('active', true, 2, 4).map(element => element.getData('num'))); // []
    console.log("After");
    console.log(newGroup.getMatching('active', true, 0).map(element => element.getData('num')));  // [0, 1, 2, 3, 4]
    console.log(newGroup.getMatching('active', true, 1).map(element => element.getData('num'))); // [1, 2, 3, 4]
    console.log(newGroup.getMatching('active', true, 2, 4).map(element => element.getData('num'))); // [2, 3]
  }

Example Test Code

This snippet contains the unit tests: https://jsfiddle.net/7x5Lpse1/16/

[photonstorm]

Thanks for opening this issue, and for submitting a PR to fix it. We have merged your PR into the master branch and attributed the work to you in the Change Log. If you need to tweak the code for whatever reason please submit a new PR.