Return proper error code when server is loading

[ceronman]

When requests are made to rust-analyzer and the server is still loading, a response error is returned with the code ContentModified and text "Rust Analyzer is still loading...". This error code doesn't seem to be the more appropriate for this situation. Using ServerNotInitialized seems better.

As this is such a small change, I have not created an issue for it.

[matklad]

Unsure about this. The spec doesn't specify when ServerNotInitialized should be emmited at all. I suspect it is for the cases where (an erroneous) client sends requests before initialization sequence completed.

ContentModified is used according to it's intended cases here: sereve is initialized, but it still constantly modifies it's internal model of the world, as fileds are still being rear from the disk.

Why does this matter at all? The clients should just silently ignore content modified errors.

[ceronman]

@matklad This doesn't matter much. I was just surprised by the message and thought that ServerNotInitialized was more suitable. But what you say makes sense. Feel free to close the PR.

[matklad]

Let's just change the message to "waiting for cargo metadata or cargo check" while keeping the error code.

[ceronman]

@matklad I updated the PR with your suggestion just in case. Feel free to merge or close.

[matklad]

Thanks!

bors r+

[matklad]

In case your are curious, microsoft/language-server-protocol#511 is the related protocol issue z

[bors]

Build succeeded:

• Rust (macos-latest)
• Rust (ubuntu-latest)
• Rust (windows-latest)
• TypeScript (ubuntu-latest)
• TypeScript (windows-latest)

[lnicola]

changelog fix (first contribution) improve "still loading" error message

[kjeremy]

See rust-analyzer/lsp-server#29 for clarification of ServerNotInitialized