Steps to Reproduce

    <charts id="chart" type="line" title="Season Average Temperature"/>
    <script defer="true" src="promise.js"/>

1. run the page in Firefox and Safari
2. open developer tool > console tab

Current Result

Uncaught TypeError: (new Promise(...)).finally is not a function

Expected Result

no error

Debug Information

• Chrome doesn't produce the error.
• a real use case: a user includes a 3rd-party js library that calls Promise.finally, and it produces the error in the browser developer tool console. Because canvg.js override Promise.prototype, so there is no finally() available.

Workaround

1. put an empty canvg.js in the below path to override existing canvg.js in zkcharts.jar