LSP Example for Log Streaming

This is a repository adapted from lsp-sample to demonstrate

• Usage of the JSON output
• Streaming the JSON into LSP Inspector

Demo

Synopsis

• With vscode-languageclient@5.1.0-next.9, you can specify a JSON log output format with [langId].trace.server as follows:

  "languageServerExample.trace.server": {
    "format": "json", // or "text"
    "verbosity": "verbose" // or "off" | "messages"
  }

• A webview build of the LSP Inspector can be downloaded here: https://marketplace.visualstudio.com/items?itemName=octref.lsp-inspector-webview
• When using the Webview LSP Inspector, it will open a WebSocket Server taking incoming connection that sends logs following this format.
• You can stream the JSON log of any Language Server using vscode-languageclient to the LSP Inspector, and it will show a live view of the LSP connection.

Running the Sample

• Install the LSP Inspector Webview extension
• Compile and Run this Extension
  • npm install
  • npm run compile
  • F5 to run the extension
• Add the following setting:

  "languageServerExample.trace.server": {
    "format": "json",
    "verbosity": "verbose"
  },

• Open a txt file so this Language Server gets activated
• Run command "LSP Inspector: Start LSP Inspector"
• Run command "Start Stream Logs into languageServerExample.port"
• As you are typing, doing auto-completion, many messages should show up in the inspector, such as
  • textDocument/didChange
  • textDocument/completion
  • textDocument/publishDiagnostics