TypeError: Cannot set properties of undefined (setting 'cursor')

[MrCoder]

Bug Description

There is a TypeError occurring when trying to set the cursor property on an undefined object in the application.

Error Details

Uncaught TypeError: Cannot set properties of undefined (setting 'cursor')
    at userscript.js:29:28

Root Cause

The error occurs in two locations where the code attempts to set app.store.state.cursor without properly checking if app.store and app.store.state exist:

1. src/extension/script.js:20

if (app && (cursor !== null || cursor !== undefined)) {
  app.store.state.cursor = cursor; // Error: app.store.state is undefined
}

2. src/computes.js:197

if(app && (cursor !== null || cursor !== undefined)) {
  app.store.state.cursor = cursor; // Error: app.store.state is undefined
}

Problem Analysis

While both code blocks check if app exists, they don't verify that app.store or app.store.state are defined before attempting to access them. This can happen when:

• The ZenUML app hasn't fully initialized yet
• The store hasn't been created or is in an invalid state
• There's a timing issue between app creation and message handling

Proposed Solution

Add proper null/undefined checks before setting the cursor:

if (app && app.store && app.store.state && (cursor !== null || cursor !== undefined)) {
  app.store.state.cursor = cursor;
}

Files Affected

• src/extension/script.js (line 20)
• src/computes.js (line 197)

Impact

This error prevents proper cursor synchronization and may cause the application to fail silently when handling cursor position updates.

[MrCoder]

app does not expose store anymore. So just remove this code.