Shiny Updates: postMessage and browser extensions conflict

[afercia]

Noticed in Chrome, using the "Accessibility Developer Tools" extension, see ​https://github.com/GoogleChrome/accessibility-developer-tools-extension

Looks like some browser extensions may use postMessage and conflict with the updates postMessage events:

In this case, the "Accessibility Developer Tools" extension triggers two "message" events when opening the plugin details modal and passes as data an object.

Maybe, in 'updates.js' it would be safer to check if the event data is a string before trying to parse it because this line:
message = $.parseJSON( originalEvent.data );
assumes originalEvent.data is a well-formed JSON string while browser extensions or maybe also plugins might pass other types of data.

[swissspidy]

We might be able to use wp.updates.isValidResponse() inside the postMessage handler.

[swissspidy]

Actually, a simple try {} catch() {} is enough.

[swissspidy]

Fixed in [37976]