Client requests textDocument/diagnostics before textDocument/didOpen

[andrewbranch]

I don’t know how to reproduce this reliably in a fresh repo, but it’s happening every time I restart the language client/server in my window right now. In the logs, you can see two textDocument/didOpen, followed by textDocument/diagnostic for file:///Users/andrew/Developer/microsoft/typescript-go/Herebyfile.mjs, which is not one of the two that's been already opened. The textDocument/didOpen for Herebyfile.mjs comes later (very end of the logs pasted), and after that, there’s no subsequent textDocument/diagnostic request for it. This must be a bug, because I have unsaved changes in that file's editor, so the didOpen content is going to be different from the text on disk, which is the only thing we could access in order to compute diagnostics.

This actually causes us (TypeScript) to return an error, because from observation we counted on the client only asking for diagnostics for files it’s already opened. But even if we gracefully served the request, the diagnostics shown would be for the wrong content.

2026-02-05 14:51:37.763 [trace] Sending request 'shutdown - (11)'.
2026-02-05 14:51:37.764 [trace] Received response 'shutdown - (11)' in 1ms.
No result returned.
2026-02-05 14:51:37.764 [trace] Sending notification 'exit'.
No parameters provided.
2026-02-05 14:51:37.764 [trace] Received notification 'window/logMessage'.
Params: {
    "type": 3,
    "message": "handled method 'shutdown' (11) in 11.333µs"
}
2026-02-05 14:51:37.766 [trace] Sending request 'initialize - (0)'.
Params: {

}
2026-02-05 14:51:37.775 [trace] Sending notification 'initialized'.
Params: { (removed for brevity) }
2026-02-05 14:51:37.776 [trace] Sending notification 'textDocument/didOpen'.
Params: {
    "textDocument": {
        "uri": "file:///Users/andrew/Developer/microsoft/typescript-go/_packages/api/src/path.ts",
        "languageId": "typescript",
        "version": 59,
        "text": "import { Path } from \"@typescript/ast\";\r\n\r\nconst ..."
    }
}
2026-02-05 14:51:37.776 [trace] Sending notification 'textDocument/didOpen'.
Params: {
    "textDocument": {
        "uri": "file:///Users/andrew/Developer/microsoft/typescript-go/_packages/api/src/node.ts",
        "languageId": "typescript",
        "version": 44,
        "text": "import {\r\n    type Node,\r\n    type NodeArray,\r\n    type SourceFile,\r\n    ..."
    }
}
2026-02-05 14:51:37.776 [trace] Sending request 'textDocument/diagnostic - (1)'.
Params: {
    "textDocument": {
        "uri": "file:///Users/andrew/Developer/microsoft/typescript-go/Herebyfile.mjs"
    }
}
2026-02-05 14:51:37.776 [trace] Sending request 'textDocument/diagnostic - (2)'.
Params: {
    "textDocument": {
        "uri": "file:///Users/andrew/Developer/microsoft/typescript-go/_packages/api/src/path.ts"
    }
}
2026-02-05 14:51:37.776 [trace] Sending request 'textDocument/diagnostic - (3)'.
Params: {
    "textDocument": {
        "uri": "file:///Users/andrew/Developer/microsoft/typescript-go/_packages/api/src/node.ts"
    }
}
2026-02-05 14:51:37.776 [trace] Sending notification 'textDocument/didOpen'.
Params: {
    "textDocument": {
        "uri": "file:///Users/andrew/Developer/microsoft/typescript-go/_packages/api/src/async/api.ts",
        "languageId": "typescript",
        "version": 19,
        "text": "/// <reference path=\"../node.ts\" preserve=\"true\" / ..."
    }
}
2026-02-05 14:51:37.777 [trace] Sending notification 'textDocument/didOpen'.
Params: {
    "textDocument": {
        "uri": "file:///Users/andrew/Developer/microsoft/typescript-go/_packages/api/src/base/api.ts",
        "languageId": "typescript",
        "version": 12,
        "text": "/**\r\n *  ..."
    }
}
2026-02-05 14:51:37.777 [trace] Sending notification 'textDocument/didOpen'.
Params: {
    "textDocument": {
        "uri": "file:///Users/andrew/Developer/microsoft/typescript-go/_packages/api/src/proto.ts",
        "languageId": "typescript",
        "version": 2,
        "text": "export interface ConfigResponse {..."
    }
}
2026-02-05 14:51:37.778 [trace] Sending notification 'textDocument/didOpen'.
Params: {
    "textDocument": {
        "uri": "file:///Users/andrew/Developer/microsoft/typescript-go/Herebyfile.mjs",
        "languageId": "javascript",
        "version": 112,
        "text": "// @ts-check\r\n\r\nimport AdmZip from \"adm-zip\";\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n..."
    }
}

[dbaeumer]

@andrewbranch I investigated and here is what I think is happening:

• due to the code here in the TypeScript-Go extension : https://github.com/microsoft/typescript-go/blob/main/_extension/src/client.ts#L63 a diagnostic requests is sent for the tab before an open event is fired.
• the pull diagnostic code in the the language client receives the open event but since the diagnostic requestor already knows the document it skips the request. See https://github.com/microsoft/vscode-languageserver-node/blob/main/client/src/common/diagnostic.ts#L868. This is wrong for documents that are basically dirty or are restore from hot exit.

When you see this happening was the tab for Herebyfile.mjs already full restores / visible ... ?

The fix for this would be to sent another diagnostic request for Herebyfile.mjs on open even if we have already sent one for the tab. The tab one could be canceled in this scenario.

I want to point out one thing though: LSP explicitly allows sending requests for document which are not open. The contract then is that a server can use its internal state for the document to fulfil the request.

[dbaeumer]

Possible fix is here: https://github.com/microsoft/vscode-languageserver-node/tree/dbaeumer/radical-amphibian-lime

[andrewbranch]

When you see this happening was the tab for Herebyfile.mjs already full restores / visible ... ?

No, it was not visible. However, I had an agent mode chat session open. I don't recall whether that session had made edits to Herebyfile.mjs, but I've observed separately that Copilot Chat sessions tend to open, and never close, every file it's ever touched, even after restarting the editor.