next.js

b72f91b4 - [ts-next-plugin] remove typescript vfs and related metadata plugin (#78237)

[ts-next-plugin] remove typescript vfs and related metadata plugin (#78237) PR https://github.com/vercel/next.js/pull/77213 introduced replacing the custom language service and host with the `@typescript/vfs` package. It did improve performance for large codebases, but it is still a problem when the plugin is initialized multiple times with multiple virtual language services from multiple apps, resulting in **freezing the IDE**. Why did we need the "virtual language service" in the first place? It was to support features like providing completions and diagnostics for metadata export without explicitly setting the type. To achieve this, we stored a copy of the file in the virtual language service with the additional type: ```diff - export const metadata = {} + export const metadata: Metadata | null = {} ``` However, the trade-off loss is big compared to the win, and it can easily be replaced by importing the actual type — which is rational. We should carefully reconsider the support details and revisit the improvement. It could be a combination of semantic suggestion/warning to add type and auto-importing. As the first step, this PR removes the `@typescript/vfs` package and the metadata plugin features that depend on it.