What problem does this feature solve?

So, here's the situation: while reviewing some code, I came across a console output stating that the ::v-deep usage as a combinator has been deprecated, and we should use :deep(<inner-selector>) instead.

then I tried to fix this warning by doing a global search of ::v-deep in vscode, but found out that no one in the project actually used this deprecated method.

I feeling perplexed, I decided to set a breakpoint at the logging location in the compiler/sfc file. There, I found out that when n.nodes.length is 0 (I guess n.nodes is the sum of all selectors inside the parentheses) it will output this warning.

I suddenly realized that some people might use it like this :deep { property: value }, and this doesn't seem to be an illegal usage.

In the end, I fixed this error usage and the warning disappeared.

I actually wanted to ask if it's possible to improve the output of this warning ?

The picture below is while I was debugging

What does the proposed API look like?

:deep(selector) { }

😹 Okay，It's seems like no one think it need to solve, so let's close it.