refactor: adapters configured from config crate

crates/adapters/nats/src/config.rs

@@ -14,13 +14,13 @@ pub struct NatsConfig {
 }
 
 impl NatsConfig {
-    pub fn from_env() -> anyhow::Result<Self> {
+    pub fn from_config(config: &::config::NatsConfig) -> anyhow::Result<Self> {
         Self::from_vars(
-            std::env::var("NATS_URL").ok().as_deref(),
-            std::env::var("NATS_MODE").ok().as_deref(),
-            std::env::var("NATS_SUBJECT_PREFIX").ok().as_deref(),
-            std::env::var("NATS_STREAM_NAME").ok().as_deref(),
-            std::env::var("NATS_CONSUMER_NAME").ok().as_deref(),
+            config.url.as_deref(),
+            Some(&config.mode),
+            Some(&config.subject_prefix),
+            Some(&config.stream_name),
+            Some(&config.consumer_name),
         )
     }
 

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);
+}