Debugger not showing variables with a specific "reserved" name

[HiranChaudhuri]

Describe the bug

While I was trying to use an object variable "owner" I perceived it does not get values assigned as expected. This thread covers the events in this respect: https://forum.gdevelop-app.com/t/how-do-i-work-with-string-values-in-object-variable/24941

Only when I renamed the variable to "shotby" the game acted normally. My conclusion is that there are some reserved words that should not be used as variables. Be it a bug that can be removed or a necessity that should be documented, I believe something should be done about this pitfall.

To Reproduce

I attach an almost empty game. It just contains one scene with one object containing three variables. Run this game in the debugger and have a look at the instance. The variable 'owner' shows the value 'undefined' although 'onethousand' is expected.

Other details

This happened on GDevelop 5.0.0.beta93 on Ubuntu 18 amd64

[HiranChaudhuri]

As Github does not allow to upload text files I am listing game.json here:

{
  "firstLayout": "",
  "gdVersion": {
    "build": 98,
    "major": 4,
    "minor": 0,
    "revision": 0
  },
  "properties": {
    "adMobAppId": "",
    "adaptGameResolutionAtRuntime": true,
    "folderProject": false,
    "linuxExecutableFilename": "",
    "macExecutableFilename": "",
    "orientation": "landscape",
    "packageName": "com.example.gamename",
    "projectFile": "/home/hiran/Documents/GDevelop projects/My project2/game.json",
    "scaleMode": "linear",
    "sizeOnStartupMode": "adaptWidth",
    "useExternalSourceFiles": false,
    "version": "1.0.0",
    "winExecutableFilename": "",
    "winExecutableIconFile": "",
    "name": "Project",
    "author": "",
    "windowWidth": 800,
    "windowHeight": 600,
    "latestCompilationDirectory": "",
    "maxFPS": 60,
    "minFPS": 20,
    "verticalSync": false,
    "platformSpecificAssets": {},
    "loadingScreen": {
      "showGDevelopSplash": true
    },
    "extensions": [
      {
        "name": "BuiltinObject"
      },
      {
        "name": "BuiltinAudio"
      },
      {
        "name": "BuiltinVariables"
      },
      {
        "name": "BuiltinTime"
      },
      {
        "name": "BuiltinMouse"
      },
      {
        "name": "BuiltinKeyboard"
      },
      {
        "name": "BuiltinJoystick"
      },
      {
        "name": "BuiltinCamera"
      },
      {
        "name": "BuiltinWindow"
      },
      {
        "name": "BuiltinFile"
      },
      {
        "name": "BuiltinNetwork"
      },
      {
        "name": "BuiltinScene"
      },
      {
        "name": "BuiltinAdvanced"
      },
      {
        "name": "Sprite"
      },
      {
        "name": "BuiltinCommonInstructions"
      },
      {
        "name": "BuiltinCommonConversions"
      },
      {
        "name": "BuiltinStringInstructions"
      },
      {
        "name": "BuiltinMathematicalTools"
      },
      {
        "name": "BuiltinExternalLayouts"
      }
    ],
    "platforms": [
      {
        "name": "GDevelop JS platform"
      }
    ],
    "currentPlatform": "GDevelop JS platform"
  },
  "resources": {
    "resources": [],
    "resourceFolders": []
  },
  "objects": [],
  "objectsGroups": [],
  "variables": [],
  "layouts": [
    {
      "b": 209,
      "disableInputWhenNotFocused": true,
      "mangledName": "New_32scene",
      "name": "New scene",
      "oglFOV": 90,
      "oglZFar": 500,
      "oglZNear": 1,
      "r": 209,
      "standardSortMethod": true,
      "stopSoundsOnStartup": true,
      "title": "",
      "v": 209,
      "uiSettings": {
        "grid": false,
        "gridB": 255,
        "gridG": 180,
        "gridHeight": 32,
        "gridOffsetX": 0,
        "gridOffsetY": 0,
        "gridR": 158,
        "gridWidth": 32,
        "snap": true,
        "windowMask": false,
        "zoomFactor": 1
      },
      "objectsGroups": [],
      "variables": [],
      "instances": [
        {
          "angle": 0,
          "customSize": false,
          "height": 0,
          "layer": "",
          "locked": false,
          "name": "NewObject",
          "width": 0,
          "x": 402,
          "y": 247,
          "zOrder": 1,
          "numberProperties": [],
          "stringProperties": [],
          "initialVariables": []
        }
      ],
      "objects": [
        {
          "name": "NewObject",
          "tags": "",
          "type": "Sprite",
          "updateIfNotVisible": false,
          "variables": [
            {
              "name": "numberVar",
              "value": "42"
            },
            {
              "name": "stringVar",
              "value": "fourtytwo"
            },
            {
              "name": "owner",
              "value": "onethousand"
            }
          ],
          "behaviors": [],
          "animations": []
        }
      ],
      "events": [],
      "layers": [
        {
          "name": "",
          "visibility": true,
          "cameras": [
            {
              "defaultSize": true,
              "defaultViewport": true,
              "height": 0,
              "viewportBottom": 1,
              "viewportLeft": 0,
              "viewportRight": 1,
              "viewportTop": 0,
              "width": 0
            }
          ],
          "effects": []
        }
      ],
      "behaviorsSharedData": []
    }
  ],
  "externalEvents": [],
  "eventsFunctionsExtensions": [],
  "externalLayouts": [],
  "externalSourceFiles": []
}

[4ian]

I think it's a limitation of the debugger that removes "owner" thinking that this is a reserved name - but the variable should be working properly in the game itself (there should be not reserved name at all in the container holding variables in memory - any name can be used).

[HiranChaudhuri]

Your analysis coudl very well be true. I trusted the debuggerr and assumed the variable would contain a wrong value. After all I also accessed it with the wrong methods.

There is no logging or other output method for variables - thus I believe a correctly working debugger is absolutely required. However it is acceptable to mark some words as reserved so developers do not run into the same issue.

[PascalLadalle]

Issue confirmed on my side, undefined pops up when owner is used, even with global variables. Variable content works fine, as suggested by @4ian.

beta 93 installed on Windows10 64-bit.

[ghost]

Confirmed that this is still an issue in v5.0.140:

I wonder what (if any) other variable names do this...?

[ghost]

Ah ha! It appears to be this list of 'excluded keys' that cause problems: https://github.com/4ian/GDevelop/blob/e22611625ed2010725f9131cf74e2e022c74669e/GDJS/Runtime/debugger-client/abstract-debugger-client.ts#L315

Examples:

• _debuggerClient
• linkedObjectsManager
• HSHG
• owner
• baseTexture
• etc.

Granted, most of them aren't likely to be used as variable names. But still...