refactor: adapters configured from config crate

crates/adapters/nats/src/tests/config.rs

@@ -28,3 +28,20 @@ fn invalid_mode_errors() {
         NatsConfig::from_vars(Some("nats://test:4222"), Some("kafka"), None, None, None).is_err()
     );
 }
+
+#[test]
+fn from_config_requires_url() {
+    assert!(NatsConfig::from_config(&::config::NatsConfig::default()).is_err());
+}
+
+#[test]
+fn from_config_uses_section_values() {
+    let section = ::config::NatsConfig {
+        url: Some("nats://test:4222".into()),
+        mode: "core".into(),
+        ..Default::default()
+    };
+    let cfg = NatsConfig::from_config(&section).unwrap();
+    assert_eq!(cfg.url, "nats://test:4222");
+    assert_eq!(cfg.mode, NatsMode::Core);
+}