Initial SendLogNotification

Author: nojaf

package.json

@@ -212,6 +212,12 @@
           ],
           "default": null,
           "description": "Path to the directory where platform-specific ReScript binaries are. You can use it if you haven't or don't want to use the installed ReScript from node_modules in your project."
+        },
+        "rescript.settings.logLevel": {
+          "type": "string",
+          "enum": ["error", "warning", "info", "log"],
+          "default": "info",
+          "description": "Controls the log level of the language server. Logs below this level will be filtered out."
         }
       }
     },

server/src/config.ts

@@ -26,6 +26,7 @@ export interface extensionConfiguration {
       enable?: boolean;
     };
   };
+  logLevel: "error" | "warning" | "info" | "log"
 }
 
 // All values here are temporary, and will be overridden as the server is
@@ -55,6 +56,7 @@ let config: { extensionConfiguration: extensionConfiguration } = {
         enable: true,
       },
     },
+    logLevel: "info"
   },
 };
 

server/src/server.ts

@@ -28,6 +28,38 @@ import * as ic from "./incrementalCompilation";
 import config, { extensionConfiguration } from "./config";
 import { projectsFiles } from "./projectFiles";
 
+const notificationLevelMap = new Map([
+  ["error", p.MessageType.Error],
+  ["warning", p.MessageType.Warning],
+  ["info", p.MessageType.Info],
+  ["log", p.MessageType.Log]
+])
+
+/**
+ * Sends an LSP log notification that will appear in the ReScript Language Server Output window in VSCode. 
+ * Other LSP clients will also receive this notification, 
+ * as we utilize LanguageClient in the VSCode extension, providing this functionality at no extra cost.
+ */
+function sendLogNotification(level: p.MessageType, message: string) {
+  const currentLogLevel = notificationLevelMap.get(config.extensionConfiguration.logLevel) || p.MessageType.Info;
+
+  if (currentLogLevel >= level) {
+    const logMessageParams: p.LogMessageParams = {
+      type: level,
+      message
+    }
+    const notificationMessage: p.NotificationMessage = {
+      method: "window/logMessage",
+      jsonrpc: c.jsonrpcVersion,
+      params: logMessageParams
+    }
+
+    if (send) {
+      send(notificationMessage);
+    }
+  }
+}
+
 // This holds client capabilities specific to our extension, and not necessarily
 // related to the LS protocol. It's for enabling/disabling features that might
 // work in one client, like VSCode, but perhaps not in others, like vim.
@@ -55,18 +87,18 @@ let stupidFileContentCache: Map<string, string> = new Map();
 let codeActionsFromDiagnostics: codeActions.filesCodeActions = {};
 
 // will be properly defined later depending on the mode (stdio/node-rpc)
-let send: (msg: p.Message) => void = (_) => {};
+let send: (msg: p.Message) => void = (_) => { };
 
 let findRescriptBinary = (projectRootPath: p.DocumentUri | null) =>
   config.extensionConfiguration.binaryPath == null
     ? lookup.findFilePathFromProjectRoot(
-        projectRootPath,
-        path.join(c.nodeModulesBinDir, c.rescriptBinName)
-      )
+      projectRootPath,
+      path.join(c.nodeModulesBinDir, c.rescriptBinName)
+    )
     : utils.findBinary(
-        config.extensionConfiguration.binaryPath,
-        c.rescriptBinName
-      );
+      config.extensionConfiguration.binaryPath,
+      c.rescriptBinName
+    );
 
 let createInterfaceRequest = new v.RequestType<
   p.TextDocumentIdentifier,
@@ -333,9 +365,9 @@ let openedFile = (fileUri: string, fileContent: string) => {
             message:
               config.extensionConfiguration.binaryPath == null
                 ? `Can't find ReScript binary in  ${path.join(
-                    projectRootPath,
-                    c.nodeModulesBinDir
-                  )} or parent directories. Did you install it? It's required to use "rescript" > 9.1`
+                  projectRootPath,
+                  c.nodeModulesBinDir
+                )} or parent directories. Did you install it? It's required to use "rescript" > 9.1`
                 : `Can't find ReScript binary in the directory ${config.extensionConfiguration.binaryPath}`,
           },
         };
@@ -419,6 +451,7 @@ export default function listen(useStdio = false) {
     send = (msg: p.Message) => process.send!(msg);
     process.on("message", onMessage);
   }
+  utils.setSendLogNotification(sendLogNotification);
 }
 
 function hover(msg: p.RequestMessage) {
@@ -1183,15 +1216,15 @@ function onMessage(msg: p.Message) {
           inlayHintProvider: config.extensionConfiguration.inlayHints?.enable,
           codeLensProvider: config.extensionConfiguration.codeLens
             ? {
-                workDoneProgress: false,
-              }
+              workDoneProgress: false,
+            }
             : undefined,
           signatureHelpProvider: config.extensionConfiguration.signatureHelp
             ?.enabled
             ? {
-                triggerCharacters: ["("],
-                retriggerCharacters: ["=", ","],
-              }
+              triggerCharacters: ["("],
+              retriggerCharacters: ["=", ","],
+            }
             : undefined,
         },
       };
@@ -1202,6 +1235,8 @@ function onMessage(msg: p.Message) {
       };
       initialized = true;
 
+      sendLogNotification(p.MessageType.Info, `LSP Server started!`)
+
       // Periodically pull configuration from the client.
       pullConfigurationPeriodically = setInterval(() => {
         askForAllCurrentConfiguration();