webview - message passing broken since 1.56.0 (extension->content window)

[tintinweb]

My extension tintinweb.graphviz-interactive-preview used to work fine until the 1.56.0 update arrived a couple of days ago. Users started to report an issue with the webview not rendering dot graphs anymore Consensys/vscode-solidity-auditor#72.

The extension renders dot graphs in a webview by loading an index.html (set via webview.html), waiting for a webview.postMessage({"command":"renderDot", "value":"<dotgraph>"}).

Now, this seems to be broken since 1.56.0 for some reason and I was trying to debug it without success. I tried to keep my code very much aligned with the examples but cannot seem to find the issue.

I am using webview.postMessage() to send messages to the content window and webview.onDidReceiveMessage(handler) to receive msgs from the content window but it looks like messages that I post do not arrive at the content window's message eventlistener but instead appear in webview.onDidReceiveMessage(). This hasn't happened before 1.56.0 and I assume this may be a breaking change introduced with the latest webview changes.

https://github.com/tintinweb/vscode-interactive-graphviz/blob/master/src/features/interactiveWebview.js#L69

Would be great if someone could verify what's happening here. Either I am somehow misusing the API or this might be a bug that could affect more extensions.

Note: My extension still receives messages from the contentWindow (e.g. save dot file from the menu, initiated from within the contentWindow), however, the contentWindow does not seem to receive any messages.

Version: 1.56.2
Commit: 054a9295330880ed74ceaedda236253b4f39a335
Date: 2021-05-12T17:44:30.902Z
Electron: 12.0.4
Chrome: 89.0.4389.114
Node.js: 14.16.0
V8: 8.9.255.24-electron.0
OS: Darwin x64 19.6.0

This used to work

Steps to Reproduce:

1. get tintinweb.graphviz-interactive-preview
2. open a graphviz dot file and hit cmd + shift + p -> interactive graphviz preview beside
3. empty window (because content window is not receiving messages from the extension :/ they instead appear in the extensions message handler?! - see "unexpected command" in console (this is the extension not expecting the command that should have been posted to the contentwindow))
4. clicking on the toolbar menu - save dot opens a vscode saveas dialog -> message from contentwindow to extension works fine

[tintinweb]

closed / invalid. one of my scripts defined a postMessage method which was the root cause of the problem. seems to be working now. thanks!

[maximgx]

it works now with 0.11

[jan-dolejsi]

@tintinweb, you are a genius. I was looking at this the whole week. Same issue - I too had a convenience function postMessage. I think you saved me another week of guessing.