Add configuration option for adl-server path (#395)

packages/adl-vscode/extension.ts

@@ -1,40 +1,55 @@
-import { ExtensionContext } from "vscode";
+import { ExtensionContext, workspace } from "vscode";
 import { LanguageClient, LanguageClientOptions, Executable } from "vscode-languageclient/node.js";
 
 let client: LanguageClient | undefined;
 
 export function activate(context: ExtensionContext) {
-  const id = "adlLanguageServer";
-  const name = "ADL Language Server";
   const exe = resolveADLServer(context);
-
   const options: LanguageClientOptions = {
     documentSelector: [{ scheme: "file", language: "adl" }],
   };
 
+  const name = "ADL";
+  const id = "adlLanguageServer";
   client = new LanguageClient(id, name, { run: exe, debug: exe }, options);
   client.start();
 }
 
-/**
- * In development, resolve to the locally built server.js, and when installed
- * from VSIX, resolve to the globally installed `@azure-tools/adl` package using
- * adl-server on PATH.
- *
- * Eventually, we'll want to prefer a local install of the adl package to the
- * user's project location, but that isn't implemented yet.
- */
 function resolveADLServer(context: ExtensionContext): Executable {
   const nodeOptions = process.env.ADL_SERVER_NODE_OPTIONS;
   const args = ["--stdio"];
 
+  // In development mode (F5 launch from source), resolve to locally built adl-server.js.
   if (process.env.ADL_DEVELOPMENT_MODE) {
     const script = context.asAbsolutePath("../adl/cmd/adl-server.js");
+    // we use CLI instead of NODE_OPTIONS environment variable in this case
+    // because --nolazy is not supported by NODE_OPTIONS.
     const options = nodeOptions?.split(" ") ?? [];
     return { command: "node", args: [...options, script, ...args] };
   }
 
-  const command = process.platform === "win32" ? "adl-server.cmd" : "adl-server";
+  // In production, first try VS Code configuration, which allows a global machine
+  // location that is not on PATH, or a workspace-specific installation.
+  let command = workspace.getConfiguration().get("adl.adl-server.path") as string;
+  if (command && typeof command !== "string") {
+    throw new Error("VS Code configuration option 'adl.adl-server.path' must be a string");
+  }
+
+  if (command?.includes("${workspaceRoot}")) {
+    const workspaceRoot = workspace.workspaceFolders?.[0]?.uri?.fsPath ?? "";
+    command = command.replace("${workspaceRoot}", workspaceRoot);
+  }
+
+  // Default to adl-server on PATH, which would come from `npm install -g
+  // @azure-tools/adl` in a vanilla setup.
+  if (!command) {
+    command = "adl-server";
+  }
+
+  if (process.platform === "win32" && !command.endsWith(".cmd")) {
+    command += ".cmd";
+  }
+
   return { command, args, options: { env: { NODE_OPTIONS: nodeOptions } } };
 }
 

packages/adl-vscode/package.json

@@ -62,6 +62,19 @@
         "configuration": "./language-configuration.json"
       }
     ],
+    "configuration": [
+      {
+        "title": "ADL Language Server Path",
+        "properties": {
+          "adl.adl-server.path": {
+            "type": "string",
+            "default": "",
+            "description": "Path to `adl-server` command that runs the ADL language server.\n\nIf not specified, then `adl-server` found on PATH is used.\n\nExample (User): /usr/local/bin/adl-server\nExample (Workspace): ${workspaceRoot}/node_modules/.bin/adl-server",
+            "scope": "machine-overridable"
+          }
+        }
+      }
+    ],
     "grammars": [
       {
         "language": "adl",