src/index.ts (2)

15-15: Use a type-only import for DEvent.

Minor clarity/perf nit: mark DEvent as a type-only import.

-import { DEvent, getRecentEvents } from "./events.js";
+import type { DEvent } from "./events.js";
+import { getRecentEvents } from "./events.js";

---

671-693: Hoist fact keys to constants and consider exposing totals/success rate.

• Define FACT_* constants for the new facts (consistency with existing facts block).
• Optionally add total and success rate to ease downstream analysis.
• Rename unknown to avoid confusion with the TS unknown type.

Add constants near the existing “Facts”:

 const FACT_SENT_SIGTERM = "sent_sigterm";
+const FACT_NIX_BUILDS_SUCCEEDED = "nix_builds_succeeded";
+const FACT_NIX_BUILDS_FAILED = "nix_builds_failed";
+const FACT_NIX_BUILDS_UNKNOWN_EVENT = "nix_builds_unknown_event";
+const FACT_NIX_BUILDS_TOTAL = "nix_builds_total";
+const FACT_NIX_BUILDS_SUCCESS_RATE = "nix_builds_success_rate";

Refactor the method:

-  async reportPassFailCount(events: DEvent[]): Promise<void> {
-    let built = 0;
-    let failed = 0;
-    let unknown = 0;
+  async reportPassFailCount(events: DEvent[]): Promise<void> {
+    let built = 0;
+    let failed = 0;
+    let unknownCount = 0;

     for (const event of events) {
       switch (event.c) {
         case "BuiltPathResponseEventV1":
           built++;
           break;
         case "BuildFailureResponseEventV1":
           failed++;
           break;
         default:
-          unknown++;
+          unknownCount++;
       }
     }

-    this.addFact("nix_builds_succeeded", built);
-    this.addFact("nix_builds_failed", failed);
-    this.addFact("nix_builds_unknown_event", unknown);
+    const total = built + failed + unknownCount;
+    const successRate = total > 0 ? built / total : 0;
+    this.addFact(FACT_NIX_BUILDS_SUCCEEDED, built);
+    this.addFact(FACT_NIX_BUILDS_FAILED, failed);
+    this.addFact(FACT_NIX_BUILDS_UNKNOWN_EVENT, unknownCount);
+    this.addFact(FACT_NIX_BUILDS_TOTAL, total);
+    this.addFact(FACT_NIX_BUILDS_SUCCESS_RATE, successRate);
   }

If desired, I can also add a small block to the job summary showing these counts.

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

💡 Knowledge Base configuration:

• MCP integration is disabled by default for public repositories
• Jira integration is disabled by default for public repositories
• Linear integration is disabled by default for public repositories

You can enable these sources in your CodeRabbit configuration.