Add command to dump LSP server state

Author: nojaf

client/src/commands.ts

@@ -9,6 +9,7 @@ export { createInterface } from "./commands/create_interface";
 export { openCompiled } from "./commands/open_compiled";
 export { switchImplIntf } from "./commands/switch_impl_intf";
 export { dumpDebug, dumpDebugRetrigger } from "./commands/dump_debug";
+export { dumpServerState } from "./commands/dump_server_state";
 
 export const codeAnalysisWithReanalyze = (
   targetDir: string | null,

client/src/commands/dump_server_state.ts

@@ -0,0 +1,38 @@
+import {
+  ExtensionContext,
+  StatusBarItem,
+  Uri,
+  ViewColumn,
+  window,
+} from "vscode";
+import { LanguageClient } from "vscode-languageclient/node";
+import * as fs from "fs";
+import { createFileInTempDir } from "../utils";
+
+export async function dumpServerState(
+  client: LanguageClient,
+  _context?: ExtensionContext,
+  _statusBarItem?: StatusBarItem,
+) {
+  try {
+    const result = await client.sendRequest("rescript/dumpServerState");
+    const outputFile = createFileInTempDir("server_state", ".json");
+
+    // Pretty-print JSON with stable ordering where possible
+    const replacer = (_key: string, value: any) => {
+      if (value instanceof Map) return Object.fromEntries(value);
+      if (value instanceof Set) return Array.from(value);
+      return value;
+    };
+
+    const json = JSON.stringify(result, replacer, 2);
+    fs.writeFileSync(outputFile, json, { encoding: "utf-8" });
+
+    await window.showTextDocument(Uri.parse(outputFile), {
+      viewColumn: ViewColumn.Beside,
+      preview: false,
+    });
+  } catch (e) {
+    window.showErrorMessage(`Failed to dump server state: ${String(e)}`);
+  }
+}

client/src/extension.ts

@@ -371,6 +371,10 @@ export function activate(context: ExtensionContext) {
     customCommands.dumpDebug(context, debugDumpStatusBarItem);
   });
 
+  commands.registerCommand("rescript-vscode.dump-server-state", () => {
+    customCommands.dumpServerState(client, context, debugDumpStatusBarItem);
+  });
+
   commands.registerCommand("rescript-vscode.showProblems", async () => {
     try {
       await commands.executeCommand("workbench.actions.view.problems");

package.json

@@ -88,6 +88,10 @@
       {
         "command": "rescript-vscode.debug-dump-start",
         "title": "DEBUG ReScript: Dump analysis info"
+      },
+      {
+        "command": "rescript-vscode.dump-server-state",
+        "title": "DEBUG ReScript: Dump LSP Server State"
       }
     ],
     "keybindings": [

server/src/server.ts

@@ -1485,6 +1485,50 @@ async function onMessage(msg: p.Message) {
       if (extName === c.resExt) {
         send(await signatureHelp(msg));
       }
+    } else if (msg.method === "rescript/dumpServerState") {
+      // Custom debug endpoint: dump current server state (config + projectsFiles)
+      try {
+        const projects = Array.from(projectsFiles.entries()).map(
+          ([projectRootPath, pf]) => ({
+            projectRootPath,
+            openFiles: Array.from(pf.openFiles),
+            filesWithDiagnostics: Array.from(pf.filesWithDiagnostics),
+            filesDiagnostics: pf.filesDiagnostics,
+            rescriptVersion: pf.rescriptVersion,
+            bscBinaryLocation: pf.bscBinaryLocation,
+            editorAnalysisLocation: pf.editorAnalysisLocation,
+            namespaceName: pf.namespaceName,
+            hasPromptedToStartBuild: pf.hasPromptedToStartBuild,
+            bsbWatcherByEditor:
+              pf.bsbWatcherByEditor != null
+                ? { pid: pf.bsbWatcherByEditor.pid ?? null }
+                : null,
+          }),
+        );
+
+        const result = {
+          config: config.extensionConfiguration,
+          projects,
+          workspaceFolders: Array.from(workspaceFolders),
+        };
+
+        let response: p.ResponseMessage = {
+          jsonrpc: c.jsonrpcVersion,
+          id: msg.id,
+          result,
+        };
+        send(response);
+      } catch (e) {
+        let response: p.ResponseMessage = {
+          jsonrpc: c.jsonrpcVersion,
+          id: msg.id,
+          error: {
+            code: p.ErrorCodes.InternalError,
+            message: `Failed to dump server state: ${String(e)}`,
+          },
+        };
+        send(response);
+      }
     } else {
       let response: p.ResponseMessage = {
         jsonrpc: c.jsonrpcVersion,