add extraFlags setting

Author: LiemLB

package.json

@@ -50,6 +50,11 @@
           "type": "boolean",
           "default": false,
           "description": "allow impure environment (nix develop --impure)"
+        },
+        "shells.nixCommandExtraFlags": {
+          "type": "array",
+          "default": [],
+          "description": "additional flags can be add via this option (eg. ['--impure', '--fallback', '--refresh'])"
         }
       }
     }

src/extension.ts

@@ -62,14 +62,19 @@ async function isNixAvailable(): Promise<boolean> {
  * Securely extracts environment variables from nix develop
  */
 function getFlakeEnvironment(flakeDir: string): Promise<NodeJS.ProcessEnv> {
-	const config = vscode.workspace.getConfiguration('shells');
-	const impure = config.get<boolean>('impure');
-	const args = (impure) ? ['develop', flakeDir, '--impure', '--command', 'env'] : ['develop', flakeDir, '--command', 'env']
+	const config = vscode.workspace.getConfiguration("shells");
+	const impure = config.get<boolean>("impure");
+	const nixCommandExtraFlags = (impure ? ["--impure"] : []).concat(
+		config.get<string[]>("nixCommandExtraFlags", [])
+	);
+	const args = ["develop", flakeDir]
+		.concat(nixCommandExtraFlags)
+		.concat(["--command", "env"]);
 
 	return new Promise((resolve, reject) => {
 		const env: NodeJS.ProcessEnv = {};
 
-		outputChannel.appendLine(`[${new Date().toISOString()}] Running: nix develop ${flakeDir} ${(impure) ? '--impure' : ''} --command env`);
+		outputChannel.appendLine(`[${new Date().toISOString()}] Running: nix ${args.join(" ")}`);
 		outputChannel.appendLine('='.repeat(80));
 
 		const proc = spawn('nix', args, {