registry: use aqua backend for npm

registry/npm.toml

@@ -1,4 +1,4 @@
-backends = ["npm:npm"]
+backends = ["aqua:npm/cli", "npm:npm"]
 description = "the package manager for JavaScript"
 idiomatic_files = ["package.json"]
 overrides = ["node"]

src/backend/npm.rs

@@ -64,8 +64,10 @@ impl Backend for NPMBackend {
         let package_manager = settings.npm.package_manager;
         let tool_name = self.tool_name();
 
-        // Avoid circular dependency when installing npm itself
-        // But we still need the configured package manager for installation
+        // Explicit `npm:npm` still bootstraps through node's bundled npm even
+        // when the registry shorthand prefers aqua. Keep node here so users of
+        // the npm backend, or the registry fallback, wait for that bootstrap
+        // npm before installation starts.
         if tool_name == "npm" {
             return match package_manager {
                 NpmPackageManager::Auto => Ok(vec!["node"]),

src/cli/args/backend_arg.rs

@@ -701,11 +701,20 @@ mod tests {
         let fa: BackendArg = "gem:bashly".into();
         assert_eq!(BackendType::Gem, fa.backend_type());
 
-        let fa: BackendArg = "npm".into();
+        let fa: BackendArg = "npm:npm".into();
         assert_str_eq!("npm:npm", fa.full());
         assert_eq!(BackendType::Npm, fa.backend_type());
     }
 
+    #[tokio::test]
+    async fn test_bare_npm_uses_registry_tool() {
+        let _config = Config::get().await.unwrap();
+
+        let fa: BackendArg = "npm".into();
+        assert_str_eq!("aqua:npm/cli", fa.full());
+        assert_eq!(BackendType::Aqua, fa.backend_type());
+    }
+
     #[tokio::test]
     async fn test_backend_arg_pathname() {
         let _config = Config::get().await.unwrap();