Enable always using the latest nightly Dafny release (#196)

### Changes

Add an option "latest nightly" at the end of the "Preferred version" list, that will cause the IDE to download and use the latest nightly Dafny release

### Testing

Manually configured the IDE to use the latest nightly and used that, and the same for 3.7.

package.json

@@ -207,7 +207,8 @@
             "3.5.0",
             "3.4.2",
             "3.3.0",
-            "3.2.0"
+            "3.2.0",
+            "latest nightly"
           ],
           "default": "latest",
           "description": "The preferred Dafny version to use (overriden by custom compiler and language server paths, requires restart)."
@@ -275,7 +276,7 @@
   "devDependencies": {
     "@types/glob": "^7.1.4",
     "@types/mocha": "^9.1.0",
-    "@types/node": "^12.12.70",
+    "@types/node": "^16.11.43",
     "@types/promise.any": "^2.0.0",
     "@types/proxyquire": "^1.3.28",
     "@types/vscode": "^1.68.0",
@@ -286,10 +287,11 @@
     "eslint": "^7.32.0",
     "glob": "^7.1.7",
     "mocha": "^9.2.0",
+    "node-fetch": "^3.2.6",
     "ts-loader": "^9.2.5",
     "typescript": "^4.4.3",
     "webpack": "^5.52.1",
-    "webpack-cli": "^4.5.0"
+    "webpack-cli": "^4.10.0"
   },
   "dependencies": {
     "extract-zip": "^2.0.1",

src/constants.ts

@@ -45,7 +45,8 @@ export namespace DotnetConstants {
 }
 
 export namespace LanguageServerConstants {
-  export const Latest = 'latest';
+  export const LatestStable = 'latest';
+  export const LatestNightly = 'latest nightly';
   export const LatestVersion = '3.7.0';
   export const UnknownVersion = 'unknown';
   export const DafnyGitUrl = 'https://github.com/dafny-lang/dafny.git';

src/extension.ts

@@ -32,7 +32,6 @@ export async function deactivate(): Promise<void> {
 export async function restartServer(): Promise<void> {
   await extensionRuntime?.restart();
 }
-
 class ExtensionRuntime {
   private readonly installer: DafnyInstaller;
   private client?: DafnyLanguageClient;
@@ -58,7 +57,7 @@ class ExtensionRuntime {
       return;
     }
     await createAndRegisterDafnyIntegration(this.context, this.client!, this.languageServerVersion!);
-    commands.registerCommand(DafnyCommands.RestartServer, restartServer),
+    commands.registerCommand(DafnyCommands.RestartServer, restartServer);
     this.statusOutput.appendLine('Dafny is ready');
   }