Intercept client paths

[nojaf]

I'm trying to run my language server inside a docker container.

    var _require = __webpack_require__(/*! child_process */ "child_process"),
        spawn = _require.spawn;

    return new Promise(function (resolve, reject) {
      var cp = spawn("docker", args);
      cp.stderr.on('data', function (data) {
        console.error("stderr: ".concat(data));
      });
      resolve({
        reader: cp.stdout,
        writer: cp.stdin
      });
    });

This works out but the host is on Windows and the language server is running inside Docker.
So I'm getting errors like:

stderr: [14:24:50.423 ERR] [LSP Server] HandleClientMessage - Error {"Code": -32601, "Message": "Method not found", "Data": null, "$type": "Error"} when handling notification {"Version": "2.0", "Method": "$/cancelRequest", "Params": {"Value": [[[]]], "$type": "Some"}, "$type": "Notification"}

c:\Users\nojaf\AppData\Local\Programs\Microsoft VS Code\resources\app\out\bootstrap-fork.js:5
stderr: [14:24:50.679 ERR] [LSP] PositionHandler - Getting file checker options for /workspace/c:\Users\nojaf\Projects\fantomas\src\Fantomas\RangeHelpers.fs failed

Notice: /workspace/c:\Users\nojaf\Projects\fantomas\src\Fantomas\RangeHelpers.fs
/workspace is the folder inside the container where the server is running.
c:\Users\nojaf\Projects\fantomas\src\Fantomas\RangeHelpers.fs is the client path.

Could I somehow intercept messages on the client before they go to the server to update the file path?

PS: Yes, I'm aware of devcontainers, that is not an option as I'm not running my extension in VSCode.
Please answer if file path interception is a thing here.

[dbaeumer]

LanguageClientOptions#uriConverters is your friend.

[nojaf]

@dbaeumer thank you for this pointer.
I noticed it is currently not used for the root path. Is that by design?

vscode-languageserver-node/client/src/common/client.ts

Lines 3188 to 3190 in 7d7b702

	let rootPath = this._clientOptions.workspaceFolder
	? this._clientOptions.workspaceFolder.uri.fsPath
	: this._clientGetRootPath();

[dbaeumer]

That is an oversight.

[dbaeumer]

My mistake. It is by design. The rootPath is a path not a URI. The rootURI goes through the transformer. See https://github.com/microsoft/vscode-languageserver-node/blob/master/client/src/common/client.ts#L3207