Braces inside snippet placeholders don't work correctly

[jedwards1211]

• VSCode Version: 1.40.0
• OS Version: N/A

Steps to Reproduce:

1. Create the following snippet:

	"tmp": {
		"prefix": "tmp",
		"body": "${1:{test}}"
	},

2. Insert the snippet. Cursor position will be before the closing brace:

{test|}

3. Press backspace. The closing brace will remain:

}

The cursor should start outside the closing brace, and backspace should delete the closing brace as well.

Does this issue occur when all extensions are disabled?: Yes

[vscodebot]

(Experimental duplicate detection)
Thanks for submitting this issue. Please also check if it is already covered by an existing one, like:

• Go to matching brace choosing wrong brace when selection is active. (#68551)
• Closing Brace auto-indent doesn't work properly (#40235)
• Auto-indent on closing brace (#67678)

[jedwards1211]

Well, dupe of #59292, but the fact that we have to escape the closing brace and not the opening brace is gross

[jedwards1211]

I guess there are cases where it wouldn't be desirable to avoid escaping the closing brace. I wish there were some kind of JS API for defining snippet placeholders and transforms though.

snippet`
this is a ${placeholder(1, '{test}')}
${placeholder(1, text => text.toUpperCase())}
`