Remove old chart instance when screen resizes to prevent memory leak

[cocarmon]

New Pull Request

This PR fixes the issue of the memory leak described in #5028 .

Each time the screen is resized, a new chart is created and added to the global Apex._chartInstances array. However, old chart instances were not being cleaned up on window resize, which led to a significant increase in memory usage over multiple resizes.

I extracted the logic used in the ApexCharts class’s destroy() method to remove old chart instances, moved it into a private method (_removeOldChartInstance()), and now call that method from both update() and destroy().

Fixes #5028

Below is a comparison of the memory after resizing the window 7 times. After multiple tests the average is a ~97% reduction in memory usage.

Before:

After:

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• My branch is up to date with any changes from the main branch

[junedchhipa]

@cocarmon Can you create a codepen for the issue where _chartInstances is not being cleared during resize?
When I logged _chartInstances during resize, it's always being cleared.