test: add tests for antigravity-nix feature

Author: duizendstra

test/antigravity-nix/scenarios.json

@@ -0,0 +1,7 @@
+{
+    "image": "debian:bookworm-slim",
+    "remoteUser": "vscode",
+    "features": {
+        "antigravity-nix": {}
+    }
+}

test/antigravity-nix/test.sh

@@ -0,0 +1,39 @@
+#!/bin/bash
+set -e
+
+# Test script for antigravity-nix feature
+echo "=== Testing antigravity-nix feature ==="
+
+# Test 1: Check vscode user exists
+echo "Test 1: Checking vscode user exists..."
+id vscode || (echo "FAIL: vscode user not found" && exit 1)
+echo "PASS: vscode user exists"
+
+# Test 2: Check vscode can sudo without password
+echo "Test 2: Checking passwordless sudo..."
+sudo -n true || (echo "FAIL: passwordless sudo not working" && exit 1)
+echo "PASS: passwordless sudo works"
+
+# Test 3: Check Nix is installed
+echo "Test 3: Checking Nix installation..."
+if [ -e '/home/vscode/.nix-profile/etc/profile.d/nix.sh' ]; then
+    . '/home/vscode/.nix-profile/etc/profile.d/nix.sh'
+fi
+nix --version || (echo "FAIL: nix not found" && exit 1)
+echo "PASS: Nix is installed"
+
+# Test 4: Check flakes are enabled
+echo "Test 4: Checking flakes are enabled..."
+nix flake --help > /dev/null 2>&1 || (echo "FAIL: flakes not enabled" && exit 1)
+echo "PASS: Flakes are enabled"
+
+# Test 5: Check essential commands exist
+echo "Test 5: Checking essential commands..."
+for cmd in git wget curl sudo ps; do
+    command -v $cmd > /dev/null 2>&1 || (echo "FAIL: $cmd not found" && exit 1)
+    echo "  - $cmd: OK"
+done
+echo "PASS: All essential commands available"
+
+echo ""
+echo "=== All tests passed! ==="