Request textDocument/formatting failed error when trying to use the AbstractFormatter

[RuanVanRooyenDSA]

Hey,
I am attempting to create a formatter for my language using the AbstractFormatter class. When I format the code (without saving the document) it works perfectly, but the moment I save my document and then attempt to format it I get the following popup in my VSCode extension:

Do you perhaps have any idea why this would be?

[msujew]

Hey @RuanVanRooyenDSA 👋

Can you perhaps narrow down where the error is thrown? The range property is used quite frequently throughout the abstract formatter, which makes it hard to tell where this error originates.

I believe every one of these errors should be shown (with its stack trace) in the output view of the language server. Does this help you track down the exact method/line? Note that you should disable minification for the language server build for this to work. Alternatively, you could also try debugging through the formatter.

but the moment I save my document and then attempt to format it

This is rather weird though. I can't really think of a reason why the formatting during live editing works flawlessly, but crashes once saved.

[RuanVanRooyenDSA]

Hi @msujew,
So firstly, the screenshot I provided gets thrown in the actual Extension host.
The only error I get from the language server is:

[Error - 3:09:25 PM] Request textDocument/formatting failed.
  Message: Request textDocument/formatting failed with message: Cannot read properties of undefined (reading 'range')
  Code: -32603 

Within the extension's developer tools console it also displays the following:

notificationsAlerts.ts:42 Request textDocument/formatting failed.
ERR Error: Request textDocument/formatting failed with message: Cannot read properties of undefined (reading 'range')
    at handleResponse (c:\Users\ruan.vanrooyen\Desktop\DSA\Projects\otx-editor\extension\node_modules\vscode-jsonrpc\lib\common\connection.js:565:48)
    at handleMessage (c:\Users\ruan.vanrooyen\Desktop\DSA\Projects\otx-editor\extension\node_modules\vscode-jsonrpc\lib\common\connection.js:345:13)
    at processMessageQueue (c:\Users\ruan.vanrooyen\Desktop\DSA\Projects\otx-editor\extension\node_modules\vscode-jsonrpc\lib\common\connection.js:362:17)
    at Immediate.<anonymous> (c:\Users\ruan.vanrooyen\Desktop\DSA\Projects\otx-editor\extension\node_modules\vscode-jsonrpc\lib\common\connection.js:334:13)
    at processImmediate (node:internal/timers:485:21)
    at process.callbackTrampoline (node:internal/async_hooks:130:17)

[msujew]

Hm, that's rather annoying, since the error seems to be rethrown, which changes the stack. Can you try debugging through the calls to range within the AbstractFormatter to see which one is actually throwing? You should be able to use conditional breakpoints to test for undefined to find this quickly.