review: address Copilot feedback on async-config-poll

- ConfigWatchService: read feature.enabled from the bucket's nested "keys" map
  (matching the config-stub's response shape) instead of the top level, where
  it never resolved.
- ConfigWatchService: demote the per-poll "version advanced" log to DEBUG (the
  poller runs forever and the version can advance every poll), and log the poll
  exception object so a stack trace is available under DEBUG.
- ConfigWatchService: make the boot-failure message actionable (check the
  config service is reachable / app.config.baseUrl is correct).
- RulesResource: make the response-shape Javadoc example valid JSON.

Content-Type feedback on /health and /rules is already handled by each method's
@produces("application/json...") (recorded responses carry application/json), so
no change there.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Signed-off-by: Aditya Sharma <aditya282003@gmail.com>

Author: Aditya-eddy

async-config-poll/src/main/java/com/example/asyncconfig/config/ConfigWatchService.java

@@ -53,8 +53,8 @@ public void init() {
         Map<String, Object> features = fetchBucket("app-features");
         Map<String, Object> appConfig = fetchBucket("app-config?watch=false"); // get current version
         this.appConfigVersion = intFrom(appConfig, "version", 0);
-        Object flag = features == null ? null : features.get("feature.enabled");
-        this.featuresEnabled = flag == null || Boolean.parseBoolean(String.valueOf(flag));
+        // The config bucket carries flags under a nested "keys" map (see config-stub).
+        this.featuresEnabled = boolFromKeys(features, "feature.enabled", true);
         log.info("ConfigWatchService initialized; featuresEnabled={} appConfigVersion={}",
             featuresEnabled, appConfigVersion);
 
@@ -78,12 +78,15 @@ private void startWatchPoller() {
                     int v = intFrom(resp, "version", appConfigVersion);
                     if (v > appConfigVersion) {
                         appConfigVersion = v;
-                        log.info("config watch: app-config advanced to version {}", v);
+                        // Debug, not info: the poller runs forever and the version
+                        // can advance on every poll, so info would flood normal runs.
+                        log.debug("config watch: app-config advanced to version {}", v);
                     }
                 } catch (Exception e) {
                     // At replay the async engine keep-alives when nothing is
-                    // armed; a failed poll is non-fatal to the running app.
-                    log.debug("config watch poll failed: {}", e.getMessage());
+                    // armed; a failed poll is non-fatal to the running app. Pass
+                    // the exception so a stack trace is available under DEBUG.
+                    log.debug("config watch poll failed", e);
                 }
             }
         }, "config-watch-poller");
@@ -103,8 +106,9 @@ private Map<String, Object> fetchBucket(String name) {
             return rt.getForObject(url, Map.class);
         } catch (Exception e) {
             throw new IllegalStateException(
-                "ConfigWatchService: failed to fetch config bucket '" + name
-                    + "' from " + url + " — application cannot boot", e);
+                "ConfigWatchService: failed to fetch config bucket '" + name + "' from " + url
+                    + " — application cannot boot. Ensure the config service is reachable and "
+                    + "that app.config.baseUrl points at it.", e);
         }
     }
 
@@ -119,6 +123,16 @@ private static int intFrom(Map<String, Object> m, String key, int dflt) {
         }
     }
 
+    /** Reads a boolean flag from the bucket's nested "keys" map (its real shape). */
+    @SuppressWarnings("unchecked")
+    private static boolean boolFromKeys(Map<String, Object> bucket, String key, boolean dflt) {
+        if (bucket == null || !(bucket.get("keys") instanceof Map)) {
+            return dflt;
+        }
+        Object v = ((Map<String, Object>) bucket.get("keys")).get(key);
+        return v == null ? dflt : Boolean.parseBoolean(String.valueOf(v));
+    }
+
     public boolean isFeaturesEnabled() {
         return featuresEnabled;
     }

async-config-poll/src/main/java/com/example/asyncconfig/rules/RulesResource.java

@@ -17,8 +17,12 @@
 /**
  * Rule-engine endpoint: GET /rules/{useCase}. Requires the X-Tenant-Id and
  * X-Agent-Id headers and returns the ordered rules for the (useCase, tenant),
- * read from MySQL:
- * [{"use_case","tenant","rules":[{"rule_id","constraints","actions":[...],"rule_type"}]}]
+ * read from MySQL, e.g.:
+ * <pre>
+ * [{"use_case":"ORDER_FLOW","tenant":"ACME","rules":[
+ *   {"rule_id":14,"constraints":"...","rule_type":"POST","actions":[
+ *     {"basic_action":"...","action_details":"{}","sequence":1}]}]}]
+ * </pre>
  */
 @Component
 @Path("/rules")