Download language server on startup

esbuild.js

@@ -13,9 +13,10 @@ async function main() {
     'README.md': './README.md',
     'language-configuration.json': './language-configuration.json',
     'package.json': './package.json',
-    'language-server/build/libs/language-server-all.jar': 'bin',
     'node_modules/mermaid/dist/mermaid.min.js': 'media',
   };
+  if( !production )
+      files['language-server/build/libs/language-server-all.jar'] = 'bin'
   await build({
     entryPoints: [
       'src/extension.ts'

package.json

@@ -144,6 +144,11 @@
                     "type": "boolean",
                     "default": false,
                     "description": "Enable additional warnings for things like future deprecations, discouraged patterns, and so on."
+                },
+                "nextflow.targetVersion": {
+                    "type": "string",
+                    "default": null,
+                    "markdownDescription": "Target version of Nextflow to be used by the language server."
                 }
             }
         }
@@ -154,6 +159,7 @@
         "package": "npm run check-types && node esbuild.js --production && (cd build ; vsce package -o nextflow.vsix)"
     },
     "devDependencies": {
+        "@microsoft/vscode-file-downloader-api": "^1.0.1",
         "@types/node": "^20",
         "@types/vscode": "^1.73.1",
         "@vscode/vsce": "^3.2.1",
@@ -163,5 +169,8 @@
         "typescript": "^5.7.2",
         "vscode-jsonrpc": "^8.0.2",
         "vscode-languageclient": "^8.0.2"
-    }
+    },
+    "extensionDependencies": [
+        "mindaro-dev.file-downloader"
+    ]
 }

src/extension.ts

@@ -1,7 +1,9 @@
 import buildMermaid from "./utils/buildMermaid";
 import findJava from "./utils/findJava";
+import * as fs from 'fs';
 import * as path from "path";
 import * as vscode from "vscode";
+import { getApi } from "@microsoft/vscode-file-downloader-api";
 import {
   LanguageClient,
   LanguageClientOptions,
@@ -13,6 +15,35 @@ let extensionContext: vscode.ExtensionContext | null = null;
 let languageClient: LanguageClient | null = null;
 let javaPath: string | null = null;
 
+function getDefaultVersion() {
+  return "1.0.3";
+}
+
+async function getLanguageServerPath() {
+  if (!extensionContext) {
+    return null;
+  }
+  const devPath = path.resolve(
+    extensionContext.extensionPath,
+    "bin",
+    "language-server-all.jar"
+  );
+  if( fs.existsSync(devPath) ) {
+    vscode.window.showInformationMessage("Using local build of language server.");
+    return devPath;
+  }
+  const version = vscode.workspace
+    .getConfiguration("nextflow")
+    .get("targetVersion") as string ?? getDefaultVersion();
+  const fileDownloader = await getApi();
+  const serverUri = await fileDownloader.downloadFile(
+    vscode.Uri.parse(`https://github.com/nextflow-io/language-server/releases/download/v${version}/language-server-all.jar`),
+    "language-server-all.jar",
+    extensionContext
+  );
+  return serverUri.fsPath;
+}
+
 function startLanguageServer() {
   vscode.window.withProgress(
     { location: vscode.ProgressLocation.Window },
@@ -57,13 +88,15 @@ function startLanguageServer() {
             protocol2Code: (value) => vscode.Uri.parse(value),
           },
         };
+        let serverPath = await getLanguageServerPath();
+        if (!serverPath) {
+          resolve();
+          vscode.window.showErrorMessage("Failed to retrieve language server.");
+          return;
+        }
         let args = [
           "-jar",
-          path.resolve(
-            extensionContext.extensionPath,
-            "bin",
-            "language-server-all.jar"
-          ),
+          serverPath,
         ];
         // uncomment to allow a debugger to attach to the language server
         // args.unshift("-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=5005,quiet=y");