How to enable logs for Language server in Visual Studio Code

Question

In the Language Server Extension Guide it says:

'If you are using vscode-languageclient to implement the client, you can specify a setting [langId].trace.server that instructs the Client to log communications between Language Client / Server to a channel of the Language Client's name.

For lsp-sample, you can set this setting: "languageServerExample.trace.server": "verbose". Now head to the channel "Language Server Example". You should see the logs:

Where and how exactly do I specify this setting in VS Code?

Answer 1

What I do for php language server is adding "log": true to launch.json file, Then the compiler will try to show logs when you press f5 to start debugging. But from what I understand from the documentation you have shared in your question, You can follow this instructions (I don't guarantee this will work, As I mentioned this is the instruction for what you have shared in your question):

• Press Ctrl+comma.
• Search for "trace server".
• Now languages should be listed. If you are on the latest version of vscode, choose verbose in any language server you want.
• If you are on an older version of vscode, then choose the pencil button next to the language you want, and select "verbose".

Answer 2

Found it!

You need to create a new Node.js Attach run configuration in your launch.json.

{
    "name": "Attach",
    "port": 6009,
    "request": "attach",
    "skipFiles": [
        "<node_internals>/**"
    ],
    "type": "pwa-node"
},

And change the port from default 9229 to 6009. You also need to pass this 6009 port in the ServerOptions when instantiating new LanguageClient():

After that, when you start your plugin with F5, you can now go to the Run view and run the newly created "Attach" configuration alongside your client process:

When both processes are running, you can switch between them in the Call Stack section to see either your client console.logs or your language server's:

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